Interesting Powerpack Differences (DC)

[peteski]

I suspect that the earlier assesment that he peak AC component in the older, unfiltered power packs allowed the LED lights to illuminate brightly even with the motor running slow is correct.

So it is a tradeoff - buzzing motor with brighter headlights, or slow quiet running with dim lights.

Many years ago, before DCC, there used to be a constant lighting circuit available. It fed a high frequency voltage to the track, while the power pack still provided the motor voltage. The motor would not react to the AC voltage, but the light-bulbs would see it, and glow brightly.  That way you could have a slow running (or even stopped) trains with headlights and car lighting fully illuminated.  I don't know if you can still buy one of these units.

The other alternative would be to rework all your locos with constant lighting circuit. That would require replacing all the lights with 1.5V bulbs and installing diodes in each loco.

[mmagliaro]

That high-frequency AC constant-brightness circuit is covered in Peter Thorne's "Practical Electronic Projects for Model Railroaders", from which I built the very throttle I use today, even though that book came out in 167 B.C.
(actually, 1973, I believe).

Love that book, by the way.

If you do find a commercial high-frequency AC circuit to drive your headlights (or build one), I am wondering about using that
on coreless motors.  They don't have the high inductance of a conventional motor, so I'm worried that the AC will not
be "invisible" to them and ruin them.  I confess, I am rusty on my motor and inductance theory since college, so maybe
somebody else can help out here.   Will, say, 20 kHz AC at 6 volts or so cook a coreless motor?

[mmagliaro]

I found this:

http://www.rokuhan.com/english/products/index.php

The Rokuhan RC02 throttle.  It appears to have the high-frequency AC built in, controllable by a separate knob.
So you should be able to make our headlights come on just as you wish, before the engine moves, and make them
as bright as you like.  (This is all assuming you are using straight DC, not DCC)

[tehachapifan]

Wow! Thanks for the link. So....this should work with modern N scale locos?

[peteski]

Wow! Thanks for the link. So....this should work with modern N scale locos?

That power pack is designed to supply up to 800mA.   It should be able to supply power to couple of any N scale locos (modern or ancient).  If you were running a lit passenger car train (using old fashion incandescent bulbs), then depending on how many cars you had in the train, you might be reaching the max. capacity of the throttle.