NEW LIGHT BULB DESIGNS

Improvements and Problems

We have seen some impressive improvements in light bulb design. But the government ban on the old technology incandescent lamps and T-12 fluorescents brings in a few problems that government does not seem to care about. It should be unconstitutional for government to have the power to ban things that politicians don't like.

Glossary

PROBLEMS WITH NEW TECH LIGHTS

PROBLEMS WITH
EXISTING FIXTURES

  • New lamps too big to fit
  • Need different power supply
  • Need different fixture type
  • Many lamps can't go base-up
  • Can't use existing dimmers
  • Must replace T12 ballast

LIGHT CURVE IS
CHOPPY, NOT FLAT

  • Colors are misidentified
  • Prevent scientific measurement
  • Problems with photography
  • Changes in how things look
  • Filters give wrong colors
  • Paint looks the wrong color

POWER FACTOR,
HARMONICS, & NOISE

  • Draws more current in wires
  • Damage to relay contacts
  • Blocks carrier-current signals
  • Radio and TV interference
  • Low-power-factor utility charges
  • Fakes carrier-current signals

PROBLEMS WITH
SPECIAL USES

  • New lamps deny outdoor use
  • Motion detector wears out CFL
  • Can't use light show controller
  • Motion lamp grid won't rotate
  • Lamps can't be flashed rapidly
  • Blinks when 3-way switches off

PROBLEMS WITH
FURNITURE LAMPS

  • 3-Way bulb switch wears out CFL
  • UV light turns plastic yellow
  • Heat melts plastic lampshade
  • Rainbow lampshade has no color
  • Light makes reading difficult
  • Squiggle bulb looks stupid

OTHER STUFF THAT
DOESN'T WORK

  • Can't use enclosed fixture
  • Floodlight husk overheats bulb
  • Bulb sticks out of tulip shade
  • Bulb-clip shade won't work
  • Bulb blinks when turned off
  • Strobe disc won't show speed
.

LIGHT BULB TABLE
.
Lamp
Type
Used		 Fit
Lamp
Used		 Heat
Diss
Prob		 Must
Vent
Case		 Out-
door
Use		 Mot-
ion
Det		 Dim
or
Touch		 Stage
Light
Use		 Conc
Sou-
rce		 Flat
Spec-
trum		 Sci-
ence
Use		 Color
ID
Match		 Art
Color
Use		 Color
Photo
Use		 Strobe
Disc
Use		 Res-
istor
Load
.
Natural Daylight n.a. n.a. n.a. Yes No No No Hard Yes Some Best Best Best No No
Incandescent Yes Norm OK Yes Yes Yes Yes Yes Slope Yes Good Good Best Some Yes
Halogen Yes Prob Req Some Yes Yes Yes Yes Slope Yes Best Best Best Some Yes
Old  Fluorescent Tube OK OK Case No No No No No No Fair Fair Good Some • No
Phosphor CFL Some OK Req Case No No No No No No Fair Poor Fair No No
Bright Line CFL Some OK Req Case No No No No No No Poor ‡ Poor Poor No No
RGB LED Some OK OK Some OK * Some Some Some No No Poor ‡ Poor ‡ Poor Some ◊ No
Phosphor LED Some OK OK Some OK * Some Some Some No † No Fair Fair † Poor Some ◊ No
Mercury Vapor Huge Prob Req Yes No No No No No No Bad Bad Bad Yes ◊ No
Sodium Low Press Huge Prob Req Yes No No No No No No None None None Yes ◊ No
Sodium High Press Huge Prob Req Yes No No No No No No Bad Bad Bad Yes ◊ No
High Int Discharge Huge Prob Req Yes No No No No No No Bad Bad Poor Yes ◊ No
Plasma Sulfur No Prob Req ? No No No No ? ? ? Good? Good? ? ◊ No
Plasma Mercury No Prob Req ? No No No No ? ? ? Good ? Good ? ? ◊ No
Elect Stim Luminance Some OK OK Case No Yes ? No ? ? Good ? Good ? Good ? No ◊ No
Xenon Flashtube No Some Some Case Yes No SFX Yes No No Fair No Best No No
Neon Tubes No OK OK High No No No Some No No Bad SFX Bad Yes ◊ No
Full Spectrum Source Mult OK Some Some Some Some No No Yes Poss Best Best Best No No
.
n.a. - not applicable
? - unknown or not certain (page author can't obtain)
* - Can damage a relay or TRIAC
† - Used in full spectrum source
‡ - Useful for anomalous color vision
◊ - Must not have switching power supply
• - Must not have lead-lag ballast
Case - Should be in an enclosure 		High - Must be out of reach
Huge - Much larger than normal fixture
Mult - Multiple lamps
OK - No restrictions
Poss - Possibly useful
Prob - Is a problem
Req - Required
Slope - Red end stronger than blue end 		Some - Some products work
SFX - For special effects
Tube - Old-style fluorescent tube
 
 
The full spectrum source combines
several sources to obtain a nearly
flat spectrum.
.

ABOUT THE VARIOUS TECHNOLOGIES

The spectra in this page were obtained using the methods found here:
Build a Spectroscope

How different lights change the appearance of colors in a box of 64 Crayola® crayons:
The Crayon Trials

INCANDESCENT LAMPS

Spectrum: incandescent spectrum

The problems:

  1. The law requires the manufacture of old-style bulbs to end.
  2. The biggest problem with the incandescent lamp is that increasing the efficiency (which the law requires) shortens its life. Halogen technology (see below) improves this somewhat, but adds some of its own problems.
  3. Another problem with incandescent lamps is that they are usually restricted to low color temperatures. Color temperature changes with bulb wattage. Bulb coatings are used on some products to raise the color temperature. While these still produce a continuous spectrum, the spectral response has a notch in it.
  4. Dimming changes color temperature

The biggest problem with the ban is that it leaves some uses with nothing to replace burned-out lamps with. These uses include:

  1. Fixtures the new lightbulbs will not physically fit into
  2. Fixtures that can not take the extra heat of a halogen bulb
  3. Bulbs that need ventilation, and can't be put into an enclosed fixture.
  4. Hostile environments that would cause new technology bulbs to fail quickly (oven, freezer, etc.)
  5. Outdoor uses (often prohibited in the instructions of new technology bulbs)
  6. Touch lamps (won't light, blink the new lamps, or greatly shorten the lives of new lamps)
  7. Motion detector security fixtures (won't light, blink the new lamps, get stuck on, or drastically shorten the lives of new lamps)
  8. Dimmers (won't light, blink the new lamps, dimming is not smooth, flickering, or greatly shorten the lives of new lamps)
  9. Stage lighting and light show devices (won't light, blink the new lamps, or drastically shorten the lives of new lamps)
  10. The need for a concentrated light source for focused lighting or projection equipment
  11. Photometry and colorimetry equipment need a flat spectral curve
  12. The need for a flat continuous spectrum for scientific purposes (none of the currently sold new technologies provide this)
  13. The need for accurate visual color identification (none of the currently sold new technologies provide this)
  14. The need to visually match colors made through different processes accurately
  15. An artist's need for balanced light to create art with
  16. An artistic need for balanced light for interior decorating purposes
  17. Electronic devices that use the current-limiting properties of incandescent filaments as ballasting loads (at least one guitar amp)
  18. Various devices (e.g. incubators) and toys (e.g. the Easy Bake Oven) that use certain light bulbs as controlled heat sources
  19. Users of the techniques outlined below to make other bulbs work with old equipment need old bulbs for the loads

Using incandescent lamps as loads to keep old devices working with other kinds of lamps:

  1. For a load for a device feeding other kinds of lamps, connect two lamps of twice the wattage of one of the typical lamps in series. They won't burn out.
  2. Keep a few spares in case of breakage. Buy them now. Halogen lamps might work, but they might not.

Techniques to get around the problems:

  • Techniques that adapt the new lamps (but some require some old technology lamps to work) are listed under each new type of lamp.
  • If the lamp is a load in an electronic device, connecting two lamps of twice the wattage in series might work. They won't burn out. But the temperature coefficient curve might not be the same.
  • Replacing fixtures is an expensive solution to bulbs that won't fit or work in old fixtures.

HALOGEN LAMPS

Spectrum: halogen spectrum

The problems:

  1. The major problem with halogen bulbs is heat. Too often, the fixture can't take the heat from the replacement bulb.
    • One solution is expensive: replace the fixture.
    • Another solution is to replace a Bakelite or plastic lamp socket with a porcelain socket.
    • Reduce the wattage of the bulb.
  2. Use in a high temperature environment will shorten life.
  3. Lamp fails quickly if outside surface is contaminated (only exposed quartz tube lamps).
  4. Color temperature changes with wattage.
  5. Dimming changes color temperature

OLD TECHNOLOGY FLUORESCENT LAMPS

Spectrum: old fluorescent spectrum

The problems:

  1. The biggest problem is size. An old-style fluorescent lamp will not fit into the space taken by the incandescent lamp it is replacing
  2. The government has also banned the T-12 fluorescents, necessitating replacing these fixtures when the bulbs burn out.
  3. If a dimmer was used, it will have to be removed, or replaced with a special system designed for fluorescent lamps.
  4. Some remote control and timer systems work if one incandescent lamp is still on the circuit. Use the load technique above.
  5. Can't be used in hostile environments.
  6. Cold environments cause early failure. Enclosing the fixture helps.
  7. Touch lamps are out of the question.
  8. Motion detector security systems drastically shorten lamp life. Do not use.
  9. Not a concentrated light source.
  10. The light curve is not flat. It is usually somewhat flat, with bright-line spikes in it. This is better than new technology bulbs.
  11. Can not provide a flat continuous spectrum for scientific purposes.
  12. See below for scientific, color identification, matching, and artistry solutions.
  13. Provides many different colors and tints for interior decorating purposes.
  14. Will not work for electronic devices that use incandescent filaments as ballasting loads.
  15. Useless as a heat source.
  16. Contains mercury, which scares Democrats to death.
  17. Color temperature is determined by the phosphor mix.

COMPACT FLUORESCENT LAMPS (CFL) - PHOSPHOR

The problems:

  1. Will not physically fit some fixtures. Often the screw shell is recessed too far. Try an outlet tap screw shell adapter.
  2. Most burn out faster if inside enclosed indoor fixtures.
  3. Can't be used in hostile environments.
  4. Outdoor uses might work if the fixture is enclosed.
  5. Touch lamps might work if one incandescent lamp load is still connected.
  6. Motion detector security fixtures drastically shorten the lives of these.
  7. Dimmers require a dimmable bulb.
  8. Stage lighting and light show devices can cause not lighting, blinking, and drastically shortened lamp life.
  9. Not a concentrated light source.
  10. The light curve is not flat. It is usually somewhat flat, but with gaps and bright-line spikes in it.
  11. Can not provide a flat continuous spectrum for scientific purposes.
  12. See below for scientific, color identification, matching, and artistry solutions.
  13. Provides many different colors and tints for interior decorating purposes.
  14. Will not work for electronic devices that use incandescent filaments as ballasting loads.
  15. Useless as a heat source.
  16. Contains mercury, which scares Democrats to death.
  17. Color temperature is determined by the phosphor mix.
  18. Where multiple turns of tubing are placed closely together (as in the squiggle bulbs), light from one tube is lost by striking another tube instead of radiating into the room.
  19. Three-way bulb switches in multiple lamp fixtures shorten CFL life by a factor of two.
  20. Often the power supply fails earlier than the light element itself.

COMPACT FLUORESCENT LAMPS (CFL) - BRIGHT LINE

Spectrum: CFL line spectrum

The problems:

  1. Will not physically fit some fixtures. Often the screw shell is recessed too far. Try an outlet tap screw shell adapter.
  2. Most burn out faster if inside enclosed indoor fixtures.
  3. Can't be used in hostile environments.
  4. Outdoor uses might work if the fixture is enclosed.
  5. Touch lamps might work if one incandescent lamp load is still connected.
  6. Motion detector security fixtures drastically shorten the lives of these.
  7. Dimmers require a dimmable bulb.
  8. Stage lighting and light show devices cause not lighting, blinking, and drastically shortening lamp life.
  9. Not a concentrated light source.
  10. The light curve is not flat. It has an 8 or 9 line bright-line spectrum with no fill between the lines.
  11. Can not provide a flat continuous spectrum for scientific purposes.
  12. See below for scientific, color identification, matching, and artistry solutions.
  13. Provides many different colors and tints for interior decorating purposes.
  14. Will not work for electronic devices that use incandescent filaments as ballasting loads.
  15. Useless as a heat source.
  16. Contains mercury, but not as much as the other fluorescent designs.
  17. Color temperature is determined by the mix of gases.
  18. Where multiple turns of tubing are placed closely together (as in the squiggle bulbs), light from one tube is lost by striking another tube instead of radiating into the room.
  19. Three-way bulb switches on multiple lamp fixtures shorten CFL life by a factor of two.
  20. Often the power supply fails earlier than the light element itself.

LIGHT EMITTING DIODE (LED) - RGB

Spectrum: 3 color LED spectrum

The problems:

  1. Will not physically fit some fixtures. Often the screw shell is recessed too far. Try an outlet tap screw shell adapter.
  2. Can often handle cold environments, but heat would cause it to fail quickly. Often has a heat radiating surface.
  3. Outdoor uses are usually prohibited in the instructions. Check the box.
  4. Touch lamps might work if one incandescent lamp load is still connected.
  5. The nonsinusoidal waveform has caused the relays of timers and motion detectors to weld in the on position, even at the reduced currents.
  6. The LED lamps with switching power supplies cause more compatibility troubles than the ones with simple rectifier/filter circuits.
  7. Motion detector security fixtures might work if one incandescent lamp load is still connected.
  8. Dimmers work quite well with rectifier/filter types if one incandescent load is still connected. Switching supply types do not work.
  9. Dimmable bulbs are available.
  10. Stage lighting and light show devices work quite well with rectifier/filter types if one incandescent load is still connected.
  11. Some new stage lighting and light show devices are designed to use only LEDs.
  12. Can meet low power needs for a concentrated light source for focused lighting or projection equipment.
  13. The light curve is not flat. It has three bands of nearly single color light (red, green, and blue), with gaps in between.
  14. Can not provide a flat continuous spectrum for scientific purposes.
  15. Can not be used for colorimetry.
  16. See below for scientific, color identification, matching, and artistry solutions.
  17. An increasing palette of colors and tints are available for interior decorating purposes. Some can be set for different colors.
  18. Not useful for ballasting loads.
  19. Useless as a heat source.
  20. Color temperature is determined by the relative currents through the three LEDs.
  21. Usually the power supply fails earlier than the light element itself.

LIGHT EMITTING DIODE (LED) - PHOSPHOR

Spectrum: LED phosphor spectrum

The problems:

  1. Will not physically fit some fixtures. Often the screw shell is recessed too far. Try an outlet tap screw shell adapter.
  2. Can handle cold environments, but heat would cause it to fail quickly.
  3. Outdoor uses are usually prohibited in the instructions. Check the box.
  4. With some brands, a sudden power sag causes the LED bulb to turn off. The switch must be turned off, then on, to light it again.
  5. Touch lamps might work if one incandescent lamp load is still connected.
  6. The nonsinusoidal waveform has caused the relays of timers and motion detectors to weld in the on position, even at reduced currents.
  7. The LED lamps with switching power supplies cause more compatibility troubles than the ones with simple rectifier/filter circuits.
  8. Motion detector security fixtures might work if one incandescent lamp load is still connected.
  9. Dimmers work quite well with rectifier/filter types if one incandescent load is still connected. Switching supply types do not work.
  10. Dimmable bulbs are available.
  11. Stage lighting and light show devices work quite well with rectifier/filter types if one incandescent load is still connected.
  12. Some new stage lighting and light show devices are designed to use only use LED lamps.
  13. Can meet low power needs for a concentrated light source for focused lighting or projection equipment.
  14. The light curve is not flat. It has two bands: One band has blue light. The other covers red, yellow, and green. There is a gap between the bands. The lamp emits no deep red, cyan, or violet.
  15. Can not provide a flat continuous spectrum for scientific purposes.
  16. Can not be used for colorimetry.
  17. See below for scientific, color identification, matching, and artistry solutions.
  18. An increasing palette of colors and tints are available for interior decorating purposes. Some lamps can be set to make different colors.
  19. Not useful for ballasting loads.
  20. Useless as a heat source.
  21. Color temperature is determined by the amount and type of phosphor.
  22. Usually the power supply fails earlier than the light element itself.

MERCURY VAPOR

Spectra: mercury 4 spectrum mercury 5 spectrum

The problems:

  1. The bulbs are too large and too powerful for home use. 400 W was a typical size.
  2. The high voltages needed are not allowed by electrical codes for indoor home use in some areas.
  3. These don't fit standard screw shells. A ballast is required.
  4. Some environments would cause quick failure.
  5. Outdoor use is an expected normal use.
  6. Long warm up/restrike time of several minutes precludes use in touch lamps, motion detectors, and light show equipment.
  7. Dimmers won't work.
  8. Useless for stage lighting.
  9. Can possibly meet the need for a concentrated light source.
  10. The light curve is not flat. It has 4 or 5 bright lines. Some also have a low level continuous or band spectrum from a phosphor on the glass.
  11. Can not provide a flat continuous spectrum for scientific purposes.
  12. Can not be used for colorimetry.
  13. Useless for scientific, color identification, matching, and artistry solutions.
  14. Harsh light is useless for interior decorating.
  15. Not useful as a ballasting load.
  16. Not useful as a heat source.
  17. Source of ultraviolet light unless shielded.
  18. Contains mercury, which scares Democrats to death.
  19. Color temperature is high.

LOW PRESSURE SODIUM (LPS)

The problems:

  1. The bulbs are too large and too powerful for home use. 400 W is a typical size.
  2. The high voltages and temperatures needed are not allowed by electrical codes for indoor home use in some areas.
  3. These don't fit or work in standard screw shells.
  4. Some environments would cause quick failure.
  5. Outdoor use is an expected normal use.
  6. Long warm up/restrike time of several minutes precludes use in touch lamps, motion detectors, and light show equipment.
  7. Dimmers won't work.
  8. Useless for stage lighting.
  9. Can possibly meet the need for a concentrated light source.
  10. The light curve is not flat. It has two closely spaced bright lines. The light is essentially monochromatic yellow.
  11. Can not provide a flat continuous spectrum for scientific purposes.
  12. Can not be used for colorimetry.
  13. Useless for scientific, color identification, matching, and artistry solutions.
  14. Harsh light is useless for interior decorating.
  15. Not useful as a ballasting load.
  16. Not useful as a heat source.
  17. Color temperature is not defined, as only two lines of yellow light are produced.

HIGH PRESSURE SODIUM (HPS)

Spectrum: sodium hi spectrum

The problems:

  1. The bulbs are too large and too powerful for home use. 400 W is a typical size.
  2. The high voltages and temperatures needed are not allowed by electrical codes for indoor home use in some areas.
  3. These don't fit or work in standard screw shells.
  4. Some environments would cause quick failure.
  5. Outdoor use is an expected normal use.
  6. Long warm up/restrike time of several minutes precludes use in touch lamps, motion detectors, and light show equipment.
  7. Dimmers won't work.
  8. Useless for stage lighting.
  9. Can possibly meet the need for a concentrated light source.
  10. The light curve is not flat. It has a nearly continuous spectrum in the reds and yellows, but 7 bright lines for other colors.
  11. Can not provide a flat continuous spectrum for scientific purposes.
  12. Can not be used for colorimetry.
  13. See below for scientific, color identification, matching, and artistry solutions.
  14. Harsh light is useless for interior decorating.
  15. Not useful as a ballasting load.
  16. Not useful as a heat source.
  17. Contains mercury, which scares Democrats to death.
  18. Color temperature is very low.

HIGH INTENSITY DISCHARGE (HID)

Spectrum: HID spectrum

The problems:

  1. Until recently, the bulbs were too large and too powerful for home use. 400 W was a typical size. Automotive uses have reduced size.
  2. The high voltages and temperatures needed for large sizes are not allowed by electrical codes for indoor home use in some areas.
  3. These don't fit standard screw shells, and need special circuitry.
  4. Some environments would cause quick failure.
  5. Outdoor use is an expected normal use.
  6. Long warm up/restrike time of several minutes precludes use of large sizes in touch lamps, motion detectors, and light show equipment.
  7. With a proper rectifier/filter power supply and special ballasting, small sizes might be used in touch lamps, motion detectors, and light show equipment.
  8. Dimmers won't work.
  9. Useless for stage lighting.
  10. Can possibly meet the need for a concentrated light source.
  11. The light curve is not flat. It has a nearly continuous spectrum with 9 to 12 bright lines superimposed (varies with manufacturer choice).
  12. Can not provide a flat continuous spectrum for scientific purposes.
  13. Can not be used for colorimetry.
  14. See below for scientific, color identification, matching, and artistry solutions.
  15. Harsh light is often inappropriate for interior decorating, but it can be filtered.
  16. Not useful as a ballasting load.
  17. Not useful as a heat source.
  18. Color temperature is determined by the mix of gases and metallic salts.

INDUCTION PLASMA SULFUR

The problems:

  1. Requires a new kind of fixture.
  2. Quite expensive (Typical fixture is $1000).
  3. The bulbs are too large and too powerful for home use. 1000 W was a typical size. Now, 250 W is the smallest size.
  4. The fixture is large. The ballast is almost 2 cubic feet.
  5. The high voltages and temperatures needed are not allowed by electrical codes for indoor home use in some areas.
  6. Some environments would cause quick failure.
  7. Some versions require spinning the bulb to cool it. Needs monitoring for maintenance purposes.
  8. Will not work in an enclosed fixture space. Must have ventilation.
  9. Outdoor use is an expected normal use.
  10. Long warm up/restrike time of 5 minutes precludes use in touch lamps, motion detectors, and light show equipment.
  11. Standard dimmers won't work.
  12. Useless for stage lighting.
  13. Not useful for a concentrated light source.
  14. Useful for photometry and colorimetry equipment
  15. Provides a flat continuous spectrum for scientific purposes.
  16. Meets the need for accurate visual color identification.
  17. Meets the need to visually match colors made through different processes accurately
  18. Meets the artist's need for balanced light to create in.
  19. If the size can be reduced, meets the artistic need for balanced light for interior decorating purposes
  20. Might provide many different colors and tints for interior decorating purposes in the future.
  21. Not useful as a ballasting load.
  22. Not useful as a heat source.
  23. Color temperature is determined by the temperature of the plasma.
  24. Usually the power supply fails earlier than the light element itself.

INDUCTION PLASMA MERCURY

The problems:

  1. Requires a new kind of fixture.
  2. Quite expensive (Typical fixture is $1000).
  3. The bulbs are too large and too powerful for home use. 1000 W was a typical size. Now, 250 W is the smallest size.
  4. The fixture is large. The ballast is almost 2 cubic feet.
  5. The high voltages and temperatures needed are not allowed by electrical codes for indoor home use in some areas.
  6. Some environments would cause quick failure.
  7. Will not work in an enclosed fixture space. Must have ventilation.
  8. Outdoor use is an expected normal use.
  9. Long warm up/restrike time of 5 minutes precludes use in touch lamps, motion detectors, and light show equipment.
  10. Standard dimmers won't work.
  11. Useless for stage lighting.
  12. Not useful for a concentrated light source.
  13. Provides a flat continuous spectrum for scientific purposes.
  14. Meets the need for accurate visual color identification.
  15. Meets the need to visually match colors made through different processes accurately
  16. Meets the artist's need for balanced light to create in.
  17. If the size can be reduced, meets the artistic need for balanced light for interior decorating purposes
  18. Might provide many different colors and tints for interior decorating purposes in the future.
  19. Not useful as a ballasting load.
  20. Not useful as a heat source.
  21. Color temperature is determined by the mix of gases.
  22. Contains mercury, but not as much as the other fluorescent designs.
  23. Usually the power supply fails earlier than the light element itself.

ELECTRON STIMULATED LUMINESCENCE (ESL)

The problems:

  1. Will not physically fit some fixtures. Often the screw shell is recessed too far. Try an outlet tap screw shell adapter.
  2. Hard to find.
  3. Some environments would cause quick failure.
  4. Outdoor use unknown at this time
  5. Warm up/restrike time is a few seconds
  6. Standard dimmers may not work
  7. Not useful for stage lighting.
  8. Not a concentrated light source
  9. Might be useful for photometry and colorimetry equipment with the correct phosphor mix
  10. The light curve is adjustable by changing the phosphor mix
  11. Has the advantage of the phosphors from the old style fluorescent lamps without the superimposed mercury spectrum lines.
  12. Spectrum for scientific purposes can be adjusted by changing the phosphor mix
  13. Scientific, color identification, matching, and artistry depend on the phosphor mix.
  14. Might provide many different colors and tints for interior decorating purposes in the future.
  15. Not useful as a ballasting load.
  16. Not useful as a heat source.
  17. Color temperature is determined by the phosphor mix.
  18. Often the power supply fails earlier than the light element itself.

XENON FLASHTUBE

The problems:

  1. Not useful as a lighting source, but included for photographic flash, strobe light, and comparison purposes
  2. Some environments would cause quick failure.
  3. Outdoor use OK in enclosure
  4. Warm up is instant. Restrike time depends on power supply. Will not sustain light longer than a few milliseconds.
  5. Standard dimmers do not work
  6. Not useful for normal stage lighting, used for lightning effects.
  7. Can be a concentrated light source
  8. Not useful for photometry and colorimetry equipment
  9. The bright line spectrum is useless for scientific purposes involving color
  10. Useless for scientific, color identification, matching, and artistry purposes
  11. Useless for interior decorating purposes
  12. Not useful as a ballasting load.
  13. Not useful as a heat source.
  14. Color temperature is determined by the gas pressure and voltage.

NEON TUBES

The problems:

  1. Not useful as a lighting source by itself, but included for comparison purposes
  2. A few environments would cause failure.
  3. Outdoor use OK in enclosure
  4. Warm up and restrike are instant.
  5. Standard dimmers do not work
  6. Not useful for normal stage lighting
  7. Can be a concentrated light source
  8. Not useful for photometry and colorimetry equipment
  9. The bright line spectrum of neon is useless for scientific purposes involving color
  10. The white color is essentially a fluorescent lamp.
  11. The blue color is essentially a mercury vapor lamp.
  12. The yellow color is essentially a fluorescent lamp with a yellow phosphor.
  13. The green color is essentially a fluorescent lamp with a green phosphor.
  14. Useless for scientific, color identification, matching, and artistry purposes
  15. Useful for exotic interior decorating purposes
  16. Not useful as a ballasting load.
  17. Not useful as a heat source.
  18. Color temperature is determined by the gas mix and the phosphor mix.

DEALING WITH LIGHT CURVES THAT ARE NOT FLAT

The problems related to light curves that are not linear (or Planckian) and flat can be dealt with in several ways. But the method used depends on the task at hand and the type of lamp. Trading flatness of the spectral curve for lamp efficiency is an unacceptable trade off, but that is what is being done.

The following are the tasks that normally need a flat light spectrum:

  • Scientific measurements
  • Emission Spectrophotometry
  • Reflection Spectrophotometry
  • Transmission Spectrophotometry
  • Colorimetry
  • Accurate visual color identification
  • Accurate visual color matching
  • Mixing color pigments for product use
  • Mixing color pigments for art
  • Colored light for interior decorating
  • Photography

Each use will be dealt with separately:

Scientific measurements

Various scientific measurements are taken using light, including how much light an object reflects, and the spectrum of the light emitted or reflected by an object. The flatness of the light used affects the measurements. Usually one of the measurements below has the characteristics needed for any other scientific measurement.

One effect that can spoil the readings is fluorescence. Many pigments and base materials fluoresce under ultraviolet light, including cotton, many kinds of paper, and a large number of yellow pigments. These fluorescent effects can change the readings if ultraviolet light from the source is also shining on the sample. Since the object may be used under the source providing ultraviolet light, the tests should be made with and without a UV blocking filter covering the light source. Blue light can also cause some fluorescence.

Emission Spectrophotometry

In emission photometry, the amount of light emitted by the test source is measured at each wavelength. Since no other light source is used for the measurement, the primary problem is finding an accurate flat or Planckian source for calibrating the equipment.

If the light source is not in the laboratory (e.g. photometry used in astronomy), the problem is light pollution. Light from sources in the area reflect off the atmosphere and into the measuring equipment, including the bright lines from sodium, mercury, CFLs, and HID lamps. One possible way to compensate is to take a reading of the background light reflected off the atmosphere at the same time, and use a computer to subtract it from the reading.

Reflection Spectrophotometry

Here, the light source is reflected off the sample and into the measuring equipment. The chief way to compensate for the non-flat nature of the source is to compare the reading to a reading taken from the source itself at the same wavelength at the same time. This is done with two identical detectors, one receiving dispersed light from the sample, and the other receiving dispersed light directly from the light source.

In this case, the only requirement is that the source must emit light at all wavelengths under test. This excludes all of the bright-line sources, leaving the incandescent, halogen, phosphor fluorescent, phosphor HID, sulfur lamps, and ESL.

Transmission Spectrophotometry

Here, the light source is passed through the sample and into the measuring equipment. The methods for reflection spectrophotometry work here too. Again, the only requirement is that the source must emit light at all wavelengths under test.

Colorimetry

While not as stringent as spectrophotometry, colorimetry is an attempt to measure the RGB color content of reflected light in the same way the human eye receives it. Special red, green, and blue color filters are used, and the reading is compared to the reading of the unfiltered light source. When used with a flat or Planckian light source, colorimetry returns the same values for most color temperatures of light. It is a measure of the percentage of light absorbed.

One problem with colorimetry is that the result depends on the light source. A flat or Planckian light source is assumed. The results are very different when bright lines or spectral gaps are introduced into the light source. One solution is to use several different light sources, and report readings taken from each source.

Accurate visual color identification

Accurate color identification is needed where color codes are used to identify different electronic components, wires in a cable, sizes of tools, or any other place where a color marking on an object is used to identify it. An example is the resistor color code used in electronics. Bands of color are used to indicate the resistance and tolerance of the part.

Part of the problem is that different manufacturers use different color pigments to indicate the same color. If the light source contains bright lines, or does not have a continuous spectrum, the pigments used by different manufacturers might produce wrong or ambiguous responses.

One solution is to have a guide with different samples of colors and the names of the colors they are supposed to be. Another solution is to provide a flat or Planckian light source for the task. With this solution, avoid the warm colors preferred for office use. A third solution is to use multiple light sources of different types.

Accurate visual color matching

Here the problem is finding a color that matches a desired color. The light is critical for this use. The best solution is to use several light sources, and repeat the matching test under each one. If the colors fail to match under any one source, the colors do not match.

Rather than waiting for some of the sources to start and come up to optimum light, it is better to move the color samples and standards from one place to another. A series of small booths next to each other, each with a different light source, is an ideal way to do this. Another way for larger objects is to put shutters on each light source, blocking it when it is not needed.

Mixing color pigments for product use

The problem here is to make sure the components of a product, made in factories many miles apart, match when the product is assembled. A product that has colors that match under some lights, but not under other lights, might seem to be cheaply made. Clothing is one such case. Another example is an automobile, with plastic and metal parts that are supposed to be the same color.

The method used for color matching used above should be used, but additionally, sunlight, northern sky daylight, and an overcast sky should be used, to make sure the product looks right in all conditions. One method to make matching easier is to use the primary pigments magenta, yellow, and cyan to make the pigment mix. Mixes made using these pigments match under many sources of light without adjustment.

Another related case is that of uniforms (or other sets of products that must all be the same color). When several different manufacturers, often at separated times, make uniforms for the same use, they must all use the above color matching technique, plus colorimetry, to make sure the uniforms match under all light sources. The test should be made under all known sources of artificial light, and also include sunlight, northern sky daylight, an overcast sky, and candles. The light sources used for match tests should be part of the specifications made for the order.

Mixing color pigments for art

Here, the problem is not matching a specific color, but keeping the color from changing into another color under a different kind of light. Two techniques are useful here:

  1. View the work and the mixing palette under more than one kind of light: An arrangement to switch sources of light, or a series of booths with different kinds of light, works well. Usually the following sources will be sufficient: Halogen, 2700K CFL, 6500K CFL, both CFLs on together, LED Phosphor, and HID. But Mercury vapor, sodium vapor, and sulfur are not necessary unless the work is part of a traveling show where the existing light source at the venue must be used. Where the source can not be rapidly lit and extinguished, use a shutter box to contain it, or use booths.
  2. Use mixtures of the pigment primaries Cyan, Magenta, and Yellow. These retain their intended colors under more light sources than any other mixtures (as shown in the Crayon Trials. This is because each pigment acts in only one region of the spectrum. Cyan removes red light, magenta removes green light, and yellow removes blue light. The visual ratios sent to the eye usually match the Planckian ratios expected to come from the source of light present.
  3. Avoid using colors that change hue with concentration, due to light curve slope effects. They are most susceptible to different light sources. The usual RYB primaries cause this effect.

The artist must also check to see if any of his pigments fluoresce. Use an ultraviolet source and a blue source to check this.

Colored light for interior decorating

This is not so much a matter of selection of the original light source, but of matching the effect with another light source, because the original source is no longer available. Usually matching the color temperature suffices, but the use of sources containing bright-line spectra may visually cause the colors of objects and surfaces in the room to change. Experimentation with multiple sources of different types is advisable here. A check for fluorescence is advisable too, to prevent color surprises.

Choosing colors for interior decorating

Look at the color samples under the types of light that will be used in the actual space. It might be advisable to take actual samples of the colors to be used into the actual space.

Never use a swatchbook printed on a color printer or mass-produced using three-color (CMY) or four-color (CMYK) printing to match pigment colors or select paint colors for a room. Anything other than a swatch of the actual paint or pigment used is useless for this purpose. The actual pigment will be affected by different lights in ways different from the way the inks in the swatchbook will be affected.

Photography

There are several issues to deal with when color photography is attempted in various kinds of lighting. This is complicated by the difference between film photography and digital photography. In addition, the flash on the camera is often either xenon or magnesium, producing yet another light source. The issues are as follows:

  1. Color temperature: For both film and digital photography, the colors can be adjusted in the lab (or on the computer) to cancel out this effect. Adjusting the ratio of red and blue in the picture is usually sufficient, and is done automatically by film developing machines.
  2. Green/Violet ratio: This is usually not a problem, but can be induced by the bright lines in fluorescent, CFL, LED, and HID sources. This is also lab/computer adjustable, and is often done automatically.
  3. Adjustments for color temperature and Green/Violet ratio to correct whites can cause other colors to be wrong.
  4. Flesh tones: these are usually taken care of by the two adjustments above. Occasionally, a bright line in the light source changes flesh tones in relation to the background colors. Or the flash on the camera provides a different color balance than the light in the background. Often the background is sacrificed in favor of the flesh tones.
  5. The effects of bright lines on individual colors: Occasionally, a bright line in the spectrum of the available light causes the color of a particular object being photographed to shift away from the intended color. Thus, a yellow object may look orange, brown, or green in the photo. Changing to a different light source helps. After the picture is taken, the cure is often dodging during color printing, or applying color correction to only a portion of the digital image.
  6. Fluorescence of the object under the ultraviolet light from the flash, or from a room light, may change the color produced by photography.
  7. Magnesium flash is an incandescent source. Xenon is a bright line source, but has a very large number of bright lines.
  8. Sometimes the dyes used in photographic prints or slides appear to change color when viewed using different light sources.

Build a full-spectrum source

Fortunately, we can combine sources to produce a light source containing all wavelengths of visible light in roughly equal amounts. Usually one or two LED sources are combined with sources that provide the missing wavelengths.

This page on a Full Spectrum Light Source shows one way to do this.

The main restriction on this method is that no bright-line sources can be used.

DEALING WITH RELAYS, SILICON CONTROLLED RECTIFIERS, AND TRIACS

The problems:

  1. An inductive load, such as an inductive ballast, can keep a triac or silicon controlled rectifier (SCR) from turning off. This locks the light on, or makes it flash on and off. Use a capacitor in parallel with the lamp to remove the phase shift. It also causes an inductive kick when power is shut off, causing damage to relay contacts.
  2. A rectifier/filter power supply usually draws power only at the highest peaks of the powerline cycle. This causes harmonics of the powerline frequency to get onto the power line, and fools SCR and triac switching devices. It can also cause relay contacts to pit or weld, causing loss of control. Reducing the size of the filter capacitor, and doing more filtering farther down the line can help here.
  3. A switching power supply uses a rectifier/filter supply with low filtering to power a high frequency (20-100 KHz) oscillator. The oscillator then feeds a high-frequency transformer, and a rectifier/filter with a much smaller filter capacitor. This is unpredictable when used with SCRs and triacs. It can also cause relay contacts to pit or weld by raising voltages above normal levels, causing loss of control.
  4. Arc lamps, including neon, fluorescent, and metallic vapor lamps, draw current only when the voltage is at a peak level in the powerline cycle. This causes harmonics to get back into the power lines, and plays havoc with SCR, triac, and relay controls.
  5. To protect relays in AC circuits, bypass them with capacitors large enough to prevent contact arcs, but small enough to not cause the device to operate. Be sure to check the device in the actual circuit, to make sure the capacitor does not cause spurious or improper operation when the relay is off. Also make sure the device shuts down correctly.
  6. To protect relays in DC circuits, connect a rectifier diode across the contacts, with the diode reverse biased. Any inductive kick will pass through the diode instead of damaging the contacts.
  7. Nonlinear current draw can be somewhat compensated for with a resonant transformer/capacitor network. This will always keep the current moving at the power line frequency, storing up energy, and then delivering it at the high points, without suddenly drawing extra current from the lines at the high points. This helps SCRs, triacs, and relays work.
  8. Special dimmers have been made that are less affected by load type. They are three-terminal devices that also need the neutral to use as a reference for the timing of phase-control dimmers.
  9. A special network can be inserted between the dimmer and the bulb to adjust the waveform that each device gets.

DEALING WITH POWER FACTOR, HARMONICS, and NOISE

Power factor is the portion of the power on the power lines that actually came from the generator. Resistive loads give the best (highest) power factor of 1. A purely reactive load (a capacitor or coil) gives a 90 degree leading or lagging phase shift between voltage and current, and a power factor of 0. A low power factor causes more current to flow through the power lines than that coming from the generators. This means the power company must put in larger power lines.

Harmonics are multiples of the powerline frequency that are fed back into the power lines by nonlinear loads, such as gas discharge tubes, rectifiers, and light emitting diodes. They also cause more power to flow through the lines than the generators produce. They also cause mistiming in phase controlled SCR or triac circuits, and can cause overvoltage problems that can damage semiconductors, and relay and switch contacts.

The problems:

  1. Electric motors are inductive in nature. They cause current to lag behind the voltage, lowering the power factor. Capacitors cause current to lead the voltage, so they can be connected across motors to correct the power factor.
  2. It is better to connect the capacitor to the motor, so it is connected only when the motor is running. But too many power users will not pay for the capacitors for small motors, so the power company has to provide them on the power poles.
  3. Nonlinear devices, such as gas discharge arc lights, rectifier/filter power supplies, switching power supplies, and light emitting semiconductors, cause simultaneous leading and lagging currents, because the currents flow for only a short portion of the powerline cycle. There is no easy way to completely compensate for this. But some devices can partially compensate for it:
    • A properly tuned transformer and capacitor combination can feed any kind of load, while looking like a nearly resistive load to the power source feeding it.
    • Extra rectifiers connected to phase-shift networks can smooth out the loading of a rectifier/filter power supply.
    • Similar devices could also smooth out the draw of a switching power supply.
  4. Nonlinear devices, such as gas discharge arc lights, rectifier/filter power supplies, switching power supplies, and light emitting semiconductors, cause harmonics to be fed back into the power lines. This increases the current in power lines like low power factor does, and can also cause malfunctions in electronic clocks and carrier current devices (power line remote control). The following devices can compensate for this:
    • A properly tuned transformer and capacitor combination can feed any kind of load, while looking like a nearly resistive load to the power source feeding it.
    • A choke input and output filter can remove the harmonics without interfering with carrier currents.
    • Shifting the phase of some of the lamps can smooth out the load somewhat, but cannot completely remove the harmonics.
  5. Switching power supplies and gas discharge devices put noise on the power lines, causing radio and TV interference, and malfunctions in electronic clocks, computers, and carrier current devices. The following devices can compensate for this:
    • A properly tuned transformer and capacitor combination can feed any kind of load, while looking like a nearly resistive load to the power source feeding it.
    • A choke input and output filter can remove the noise without interfering with carrier currents.

DEALING WITH SHORT LAMP LIFE

Certain lamps are not designed for certain uses. Misusing them greatly shortens the life of the lamp. Other lamps are not designed to produce the lamp life promised on the package because of factors other than the life of the light-emitting element. Here are some of the factors causing shorter than expected lamp life:

  1. The lamp is turned on and off too frequently - The average fluorescent lamp or CFL is usually good for about 6500 starts. The act of turning the lamp on is what wears it out, not leaving it on. So fluorescent lamps and CFLs should not be used in applications where they are switched on and off frequently or flashed. Do not use them for security lights with motion detectors. They should also be avoided for light show displays. Note that, because the lifetime is determined by number of starts, not the time the lamp is left on, the life in hours posted on the box are nonsense, but the law requires it to be there.
  2. Many types of lamps have shorter lives when the lamp is dimmed. This includes most gas discharge lamps and all lamps with switching power supplies that are not designed to be dimmed.
  3. A line voltage other than the rated value can shorten the lives of many kinds of lamps. A voltage that is too high will ruin most kinds of lamps. A voltage that is too low will cause electrode failure in some kinds, and cause others to fail to light even though nothing is wrong with them.
  4. Many lamps fail because the power supplies in the lamp bases overheat. This usually happens because the lamp base does not get enough ventilation to keep it cool. Some cheap brands skimp on heat dissipation. Be sure a lamp is rated for enclosed use before putting it in an enclosed fixture.
  5. Often the lifetime of the light emitting element is the life posted on the box, even though some of the components in the power supply in the base have shorter lives.
  6. Some components in the power supply in the lamp base (particularly electrolytic capacitors) have shelf lives that start timing when the part was made, not when the lamp was installed. A lamp of this type can lose all of its life sitting on the shelf as a replacement bulb.
  7. Electrical surges from thunderstorms can damage the components of the power supply in the base of the lamp, causing early failure. Surges can also damage some of the individual LEDs in the LED bulb, causing a reduction in the light output.
  8. Sunlight falling on a white LED can cause the phosphor to degrade, making the lamp dimmer and bluer than it was when new.

DEALING WITH OTHER PROBLEMS

Solutions to other problems:

New lamps too big to fit

Use different bulb or replace fixture.

Need different power supply or fixture type

Use different bulb or replace fixture.

Can't use existing dimmers

Use different kind of bulb or replace dimmer.

Can't get T12 fluorescent bulb

Either the fixture or the ballast must be replaced.

Changes in how things look

Use a different kind of bulb.

Filters give wrong colors

Use a different kind of bulb or a different color filter.

New lamps deny outdoor use

Use a different kind of bulb.

Motion detectors wear out CFLs

Use a different kind of bulb.

Can't use light show controller

Use a different kind of bulb.

Motion image shade won't rotate

Use a halogen bulb.

Lamps can't be flashed rapidly

Use a different kind of bulb.

3-Way bulb switch wears out CFLs

Use a different kind of bulb.

UV light turns plastic yellow

Use a different kind of bulb.

Heat melts plastic lampshade

Use a different kind of bulb.

Rainbow lampshade has no color

Use a different kind of bulb.

Light makes reading difficult

Use a different kind of bulb.

Can't use enclosed fixture

Use a different kind of bulb.

Floodlight husk overheats bulb

Use a different kind of bulb.

Bulb sticks out of tulip shade

Use a different kind of bulb.

Bulb-clip shade won't work

Use a different kind of bulb.

Bare squiggle bulb looks awful

Use a different kind of bulb.

Stroboscope disc gives no reading

Use bulb flashing at AC power rate.

DESIGNING COMPATIBLE ELECTRONICS

Dear Manufacturers: Points to consider when designing more efficient lamps:

  1. A flat continuous spectrum is much better than a bright line spectrum or a spectrum of multiple nonoverlapping bands. It has a CRI of 100.
  2. Give users either a wide choice of color temperatures, or an adjustable color temperature control.
  3. Also provide a variety of colors, including the primary colors of light.
  4. Use the standard names for the color temperatures of the lamps:
    • 2700 K Soft White (orange)
    • 3000 K Warm White (orangish)
    • 3500 K Bright White (yellow-orangish)
    • 4100 K Cool White (yellowish)
    • 5500 K Worklight (green tinge)
    • 6000 K SunLight (close to white)
    • 6500 K Daylight (blue tinge)
    • 7500 K Skylight (bluish)
    • 9500 K Plant Light (blue-white)
    Don't make up your own names. It confuses consumers.
  5. The best design is one that looks like a resistive load to the power source. It causes the fewest compatibility problems.
  6. A properly tuned transformer and capacitor combination can feed any kind of load, while looking like a nearly resistive load to the power source feeding it.
  7. Avoid switching power supplies. They cause more problems than anything else.
  8. Simple rectifier circuits and LEDs in series work well. With a small (7W) resistive load in parallel, these light well and can be dimmed.
  9. Extra rectifiers connected to phase-shift networks can smooth out the loading of a rectifier/filter power supply. Similar devices could also smooth out the draw of a switching power supply. But they do not remove switching frequencies.
  10. A resonant transformer and capacitor combination can feed any kind of load, while looking like a nearly resistive load to the power source feeding it.
  11. A choke input and output filter can remove the harmonics without interfering with carrier control systems.
  12. Remember that customers might have unusual uses with existing equipment, such as stage lighting, light shows, heat lamps, advertising displays, chase lights, various kinds of dimmers, 60 Hz stroboscope discs, light bulbs used as variable resistance loads, and other special devices. Don't render their equipment useless.

THE STUPID BULB

A manufacturer has made a yellow bug bulb that does not work. It still attracts bugs.

The details:

  • A light bulb attracts bugs because they mistake it for the sun or the moon.
  • Insects navigate by keeping the sun or the moon at a constant angle in their compound eyes.
  • The sun and the moon are so far away that the angle of the light never changes.
  • A light source fools the bugs. It is close enough that the angle changes. The bug compensates by changing its direction of flight to keep the angle constant. Thus, the bug keeps circling the light instead of following its original straight path.
  • Most insects see a band of light from green into the ultraviolet.
  • A bug light works by not emitting light that bugs can see. Thus, it emits only yellow, orange, and red light.
  • Humans can see what they are doing with only yellow, orange, and red light.
  • A sharp cutoff filter keeps the incandescent bug light from emitting any cyan, blue, violet, or ultraviolet light, and very little green. Thus, the bugs don't mistake this light for the moon.
  • This stupid bug lamp makes the color yellow by mixing red and green light from phosphors. It looks yellow to the customer, but emits a lot of green light. The yellow seen in this panel on your monitor is made the same way.
  • Bugs can see this green light as bright. Thus, they are attracted to this lamp.

The stupid bulb is made by Feit, which is otherwise a manufacturer of fine products.

EXPLANATION OF TERMS

  1. Ballast - An electronic device that limits current to the lamp
  2. Band Spectrum - Emission of light in a band of wavelengths
  3. Black Body Radiation - Light emitted by a perfectly black object heated to incandescence
  4. Bright-Line Spectrum - Light emitted by a hot gas, consisting of a number of discrete wavelengths, with no other light emitted
  5. CFL - Compact Fluorescent Lamp
  6. Color Rendering Index (CRI) - The quality of a lamp, measured by correctness of identification and matching of colors
  7. Color Temperature - The point on the Planckian locus of temperature of incandescence, tinting white light with color
  8. Compact Fluorescent Lamp - A small fluorescent lamp that fits a standard Edison base socket.
  9. Complex Power - The vector sum of resistive power and reactive power, measured in volt-amperes
  10. Concentrated Light Source - A light source small enough that it can be used for projectors and spotlights
  11. Continuous Spectrum - Light emitted at all visible wavelengths, with a flat or gently sloped output curve
  12. Electron Stimulated Luminescence (ESL) - Light produced by electrons beamed art a phosphor, as done in an older TV set
  13. Fluorescence - Light of one color (including ultraviolet) causing a phosphor to emit light of a different color
  14. Fluorescent Lamp - An electric arc lamp containing mercury that emits ultraviolet light, which then excites phosphors
  15. Halogen - One of the elements fluorine, chlorine, bromine, or iodine
  16. Halogen Lamp - An incandescent lamp filled with halogen gases, which keep the filament from eroding
  17. Harmonics - Multiples of a fundamental frequency (such as the 60Hz powerline frequency), causing the waveform to change.
  18. HID - High Intensity Discharge
  19. High Intensity Discharge - An electric arc lamp filled with chosen metallic salts, producing a bright-line spectrum
  20. High Pressure Sodium Vapor Lamp - An electric arc lamp filled with high pressure sodium salt, so it emits many bright lines
  21. Idiot - Any public official who thinks that banning products is the solution to anything.
  22. Incandescence - Heating a material hot enough that it emits light in a Planckian continuous spectrum
  23. Incandescent Lamp - A lamp with a carbon or tungsten filament that incandesces when electricity is passed through it
  24. Induction Plasma Lamp - A tube filled with a material that incandesces when current is induced in it by a coil of wire
  25. LED - Light Emitting Diode
  26. Light Emitting Diode - A semiconductor that is doped to give off a band spectrum of light when electrified
  27. Low Pressure Sodium Vapor Lamp - An electric arc lamp filled with low pressure sodium salt, emitting only two yellow lines
  28. Mercury Plasma Lamp - An inductive plasma lamp with mercury as the active ingredient
  29. Mercury Vapor Lamp - an electric arc lamp containing mercury, emitting only 4 visible bright lines, plus ultraviolet
  30. Metallic Arc Lamp - HID lamp
  31. Phosphor - A substance that absorbs energy from one wavelength of light, producing a band spectrum of other wavelengths
  32. Photon - An individual packet of light energy. Each photon has its own wavelength and direction of travel.
  33. Planckian Curve - The hump-shaped emission intensity curve produced by incandescence
  34. Planckian Locus - The curve representing the colors of light given off by incandescence at different temperatures
  35. Plasma - A state of matter where the atoms are hot, ionized, and emitting light
  36. Power - The amount of energy per second used by a device, calculated by multiplying voltage by current to obtain watts
  37. Power Factor - Cosine of power phase angle, with values of 1 for purely resistive loads, and 0 for purely reactive loads
  38. Power Phase Angle - The angle between the voltage peak and the current peak of complex power
  39. Reactive Power - Power with the current leading or lagging the voltage by 90 degrees, caused by coils or capacitors
  40. Rectifier/Filter Power Supply - Produces wanted voltage using transformers, rectifiers, and large capacitors
  41. Resistive Power - Power with the voltage and current in phase, as found with a purely resistive load
  42. Sinusoidal Waveform - The smooth waveform of alternating current. Causes no power problems. The waveform of a photon
  43. Spectral Gap - A portion of the visible spectrum with no light from the lamp
  44. Spectrum - A spread of the content of electromagnetic radiation, sorted by wavelength
  45. Squiggle Bulb - A CFL with the discharge tube coiled in a spiral or other convoluted pattern
  46. Stroboscope Disc - A disc with spaced lines that appear to stand still when the disc is rotating at the correct speed. Requires lamp to flash at the original power line frequency.
  47. Sulfur Lamp - An inductive plasma lamp with sulfur as the active ingredient
  48. Switching Power Supply - Produces wanted voltage using high frequency oscillators, transformers, and other components
  49. Visible Light - Electromagnetic energy with a wavelength between 380 nm and 760 nm, able to stimulate human eyes
  50. Visible Spectrum - A spread of the content of visible light, sorted by wavelength from 380 nm (violet) to 760 nm (red)
  51. Volt-Amperes (VA) - The measure of complex power
  52. Volt-Amperes Reactive (VAR) - The measure of reactive power, or the reactive portion of complex power
  53. Watts (W) - The measure of resistive power, the only portion of power on the wires produced by power generators
  54. Wavelength - The distance between successive wave crests, measured in nanometers (nm) for light, and as spectral color

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