Newbie Module Install #1

[LVRR1856]

Hey all,
Taking the first step and installing my first module. LM3-s into a P2k GP-18, going to try the 8 pin to 9 pin plug out.
I have some milling of the weight to make room, no problem, probably will with most installs ...

Reading some older posts, some guys left the Incandescent bulbs in, others added LEDs.
I'd like to keep the Incand. Bulbs at first, easy to change out later, assume they will work at 5v from what I understand is the voltage putout of the modules.
Question is .... is this a fact? Incand will work? , no resistors needed ? or just bite bullet and do LEDs ?

If LEDs ... question is ...
The ones I have have the preinstalled resistor on the positive wire, LM3s diagrams show it on the neg side ... does it matter ?

Figured I'd start a fresh thread on this. Thanks

[G8B4Life]

...I'd like to keep the Incand. Bulbs at first, easy to change out later, assume they will work at 5v from what I understand is the voltage putout of the modules.
Question is .... is this a fact? Incand will work? , no resistors needed ? or just bite bullet and do LEDs ?

This is incorrect. The output of the LM-3S outputs is slightly less than track voltage, so almost 14v. I don't know what rating of the bulbs used in P2K locomotives was but if they are 12v then your likely fine (just turn the brightness down to essentially lower the output voltage). If the bulbs are 1.5 or 3v etc then you'll need to appropriately lower the voltage with external components, or just replace with LEDs and resistors anyway..

- Tim

[snowdog]

Hey all,
If LEDs ... question is ...
The ones I have have the preinstalled resistor on the positive wire, LM3s diagrams show it on the neg side ... does it matter ?

Figured I'd start a fresh thread on this. Thanks

Electrically, the side of the LED the resistor is on does not matter. It is there to reduce the total current flow through the circuit so the LED does not get blown.

Overall, you'll be happier with LEDs.
Bryan

[LVRR1856]

Thanks - yea LEDs are once and done. Might just do one with incand and see how it goes.
I have run the P2ks at full dc throttle like 16v, but I'm thinking the P2k boards probably have resistors, which will be coming out.

Will be interesting, will report back. Wish me luck.