PS-2 Steam Upgrade - Can I run 4 sets of LED's off the headlight circuit using the 50-1901 Upgrade Kit?

Should not be a problem but to be sure wire the ones in front in series pairs. Max current draw for each LED is typically 20 milliamps. Thats if you use the smallest recommended resistor for that LED. You could use a larger resistor with minimal light loss for even lower current draw. I was testing an incandescent bulb from an upgrade kit yesterday and it drew 80ma. I would expect the circuit that drives that bulb could handle even more than that.

Pete

Sure, it'll work fine. I've run 2 markers/class lights, headlight, 2 number boards lights, cab light, and firebox light, all LEDs, off the headlamp circuit of PS32 boards in all these builds:

MTH Premier Santa Fe 2900 class Northern, or lets build a 3rd steam locomotive from junk | O Gauge Railroading On Line Forum (ogaugerr.com)

MTH Premier Western Pacific GS64 to Southern Pacific GS6 | O Gauge Railroading On Line Forum (ogaugerr.com)

MTH Premier Santa Fe Hudson restoration, aka Frankenstein's monster | O Gauge Railroading On Line Forum (ogaugerr.com)

PS2 3V board should have the same capacity on the headlamp circuit as the PS32 board.

If you run all LEDs off the headlamp circuit you just need a resistor on the LED anode. No need for a CV board or the inductor with the LEDs. Since everything is on the headlamp circuit the locomotive is dark until addressed.

as long as you don't exceed the maximum current of the headlight fet you'll be ok ! The fet  in the ps 3/2 boards are rated at 1.7 amps !

Alan

Just to add to what Lou says if you wire the LEDs in series you have to aware of the maximum voltage that the PSx board you are using. If its at least 12 volts then 4 in series ahoukd be OK as each LED drops ~3 Volts. If you wire them all in parallel then figure 20ma per LED.

Pete

Confused, are you using CV board or the PS board.  IF your moving to LED then your down around half to a third of the 6V bulb current draw and can easily handle the 4 on a circuit.  IF your using the CV add the resistor to the spot at light output and us LED instead.  G

Thanks, guys.  George - I am using one cv board.  The other two engines will use the ps3 headlight circuit.  I am going to replace the 6v bulb on the cv board with a 20ma led and proper resistor.