Adding Fan-Driven DynaChuff smoke unit to older PRR J-1a

Went to Lionel's parts page (not very user friendly unless you know what you are looking for).

Looks like if I want to try this, I would buy the Smoke Unit/Semismart/8 OHM (6308085200) plus the AC Regulator Board (691ACRGE01).  Would this work and fit in the engine?

Thanks

Ron

I'm not sure I'd buy the modern smoke unit with the regulator, why not buy a plain smoke unit and just trigger it with a simple circuit.  You'll have to do additional wiring with the AC regulator.

I have a K-Line steamer upgraded with an MTH smoke unit, it's a real frog-choker.

John,

Thanks for the quick response.

I was looking at a Lionel smoke unit so it could be triggered by the TMCC board.  Is the "simple circuit" really simple?  I like the idea of using an MTH unit but not sure how it would work in my J1.  Is there a more practical Lionel unit to buy than the one I found?

Ron

Lionel has lots of smoke units that just have the 5V regulator and a standard 27 ohm resistor.  You can drop that to a 22 ohm one for more smoke, though you'll get plenty with the 27 ohm one.

If you pick up one with the fan regulator, you could clone this circuit that ERR put into their chuff board.  Since you already have the 5V available, you could probably steal it from the smoke unit. 

This just connects in parallel with the chuff switch going to the locomotive, and the fan is driven from the output.  It isolates the chuff input from voltage spikes from turning the fan on and off.

I've also installed a DP relay on the cuff switch and used one side to drive the fan and the other side to trigger the chuff input.  Same idea, just a mechanical device.

John,

That is great!  Thank you!  This looks like a good winter project.

Ron

You still have to do extra wiring here too.

The AC Reg is pretty simple with AC in and serial data, and output to smoke.  It also is a compact design.

So I guess time and cost are the drivers.  G

I've already had enough AC regulators go up in smoke that I don't think of them first when I'm wiring smoke units.   I think part of the problem is that given the power they're handling, the heatsinking is not sufficient IMO.

Just my opinion, I think John hit it right on the head.

Thanks,

Alex

That is not the reason you used in your explanation:-)  So we will add reliability to the list:-) G

I'm just biased because of the reliability, I know my solution should work as long as the owner is alive.   I have no such faith in the regulator module.  Sometimes it's difficult for folks to find the little connectors Lionel uses as well, though I have a pretty good stock of them.

I have more faith in the manufacturers.  I assume Lionel has fixed what ever the issues were with the early Regs.

You can remove the heat shrink and then attach a heat sink, or attached the regulator to the chassis.  Harness are available.

The other advantage is that the ACREG allows more control with semi-smart smoke units.  It allows more flexibility for hi, med, lo smoke outputs via CAB-1.

It becomes a more elegant OEM upgrade.

A simpler solution to just chuffing the smoke fan is adding a double pole switch or adding a reed switch for serial chuff, and use the micro switch for fan control.  Would allow the chuff rate to be selected if you go the reed switch route.  G

I think I mentioned the DP relay driven from the chuff switch, that's a simple update and keeps the stuff isolated.