How To Measure Voltage on an Incandescent Bulb

Model Railroader Electronics and DCC
1

I have no idea.

Anyone have any suggestions for determining voltage…other than trial and error?

I don’t mind the trial part, it is the error part that concerns me.

Rich

2

Assuming you mean to determine the rated voltage: I’d take a powerpack, hook a voltmeter across the terminals, connect the bulb tot he terminals and slowly raise the voltage till the light is as bright as youd like.

But since most mrr type bulbs are either 1.5 or 12 volt, just hook a AA battery to one, if it’s bright it’s 1.5v bulb, if it doesn’t even glow its 12 volt.

3

I like that idea. Simple and telling.

Rich

4

Avoid bulbs…put in a warm white led with a 1000ohm resistor and never worry about it failing.

5

I agree, David, just curious about those incandescents that manufacturers continue to install in their locos.

Rich

6

I replied to the other thread before you started a new one.

–Randy

7

Good stuff, Randy, thanks.

Sorry about this second thread.

I was afraid that my question might get lost in the other thread.

Rich

8

Rich,

Why not! We have four Model Power threads. [:D]

Take Care!

Frank

9

There are standards based on the bulb style, base style, and color of the glass bead inside on the filament. Somewhere I’ve got a book of them (for pin-ball repairmen), I presume they can be found on-line somewhere. I have no idea if those standards were ever applied to grain-of-wheat or micro-minature bulbs.