2-8-0 Wiring problem

[jonathan]

Oh, I was referring to the switch from a "lamp" to an LED. 

[jbrock27]

 

Got it, thank you J.  Sorry I misundertood which one you were referring to.  Yes, polarity is important to determine when you want the LED lit.

Do you steam guys usually have the headlight stay on when the loco is moving in reverse or do you set it up to go off?

[jonathan]

With conventional 'lamps' I use a zener diode so the reverse light only comes on in reverse.  With an LED, I just wire it with reverse polarity so the light only comes on in reverse.

Regards,

Jonathan

[jbrock27]

Thank you Jonathan.  I did not know about the use of the zener diode.  Good tip.

[Joe Satnik]

Jonathan,

Why a Zener (as opposed to a regular diode with a higher PRV)?

What Zener voltage?

Joe

[jonathan]

Honestly I don't know the answers.  I get them at Radio Shack for 99 cents a pair. They're small and they work. That's my "why".   

Regards,

Jonathan

[Joe Satnik]

What Radio Shack part number?