What are 'grain of wheat' bulbs used for?

Question

Just wondered...

Answer 1

growing wheat ??

Answer 2

In model railroading (I am assuming, since this is the rail category), they are used in signal "heads" to display colored aspects to trains.  They are also used where scale street lights are in place, or other very small light sources.

Answer 3

they are used as a simulation for a glimmer of intelligence in an anorak

Answer 4

My car uses them in the A/C switch buttons and on the power window switches...they're just really small light bulbs used where there's not much space.

Answer 5

They are usually used in situation where you are trying to power a light with a solid state circuit.  This way, you do not need a relay to switch.  In cases where the light is part of a circuit board, you can power it directly, and since there is no relay to switch higher voltages to the light, you do not need to have two different voltages going to the board.  This reduces the chances of having a circuit burn up due to a short across the voltage traces.

This also makes it easier to manufacture, easier to install and replace, and also increases revenue for replacement parts as you now need to replace an entire circuit board instead of one small light bulb.

I also use them on the model railroad set because you can use a diode to give it a low voltage, which give a constant light source in the cab of the engine while the motor comes up to speed, instead of having it vary with the voltage.

Answer 6

Illuminating instruments and instrument panels.

Answer 7

Model railroaders use Grain of Wheat bulbs to represent street lights, canopy lights, and interior lights in model buildings and passenger cars.  Color GOW bulbs are used in model railroad signal systems to represent the colored signal lights.

Nowadays they are being replaced by LEDs (light emitting diodes), which use less power and are longer lasting.

GOW bulbs used to be used in electronic equipment and medical instruments, but those jobs are now all done with LEDs.  A couple of the previous answerers seem to be confused about this.  GOW bulbs are not used in circuit boards or in automotive lighted switches.  Those are all LED applications.