# Bachmann Heisler Firebox Flicker LEDs



## Homo Habilis (Jul 29, 2011)

I'm looking for a method to flicker the two leds in a Bachmann Heisler firebox. I have removed all of its electronics so as to place a battery (14.8v) and a RailBoss 4 receiver into the tender. The flicker circuit was on the removed Bachmann board unlike, for example, the Shay which is in the firebox and was easy to wire direct to battery voltage. 

I haven't found anything suitable after a bit of wandering the internet so I thought I ask for suggestions here. Thanks for any approaches that you can offer-up.

The best that I have found thus far is using the flicker circuits from battery tea light candles. I am resisting that since I want to use the engine's battery and not have to add a separate 3v battery and switch. Assuming that I'm calculating correctly (being electronically challenged) I'm guessing that about a 220 ohm/1 watt resistor would cut the voltage appropriately. I'm assuming a .05 current draw (amps) for the two leds (too high?). If true, where would one order such a resistor since Radio Shack is in bankruptcy protection and is usually out of stock at local stores anyway?

Again, thanks for any suggestions.

Mark

p.s. Cross-posted to LSC forum.


----------



## JPCaputo (Jul 26, 2009)

Hi, I have a large list of places that sell components besides RadioShack mainly mail order though.

In the USA

Digikey - digikey.com

Allied electronics - Alliedelec.com

Newark - newark.com

Mouser - mouser.com

Parts express - partsexpress.com

Electronics goldmine - goldmine-elec-products.com

All Electronics - allelectronics.com

Frys - frys.com


----------



## Greg Elmassian (Jan 3, 2008)

What voltage do the flicker circuits run from? I think you need to lower the input voltage to the circuit, not assume you can feed it higher voltage.

A voltage regulator IC seems to be in order.

Greg


----------



## Homo Habilis (Jul 29, 2011)

Greg:

There is not a flicker circuit anymore, just the two leds in the firebox with their wires to the tender. It was the Bachmann board that I removed from the tender that contained that circuit along with all of the rest of the original guts for the engine.


----------



## Greg Elmassian (Jan 3, 2008)

??

You said you want a method to flicker the leds

Then you say you are looking at using the circuit for tea candles.

I missed the 3v part...

Get a regulator.

LEDs want current regulating, but the flicker circuit wants 3 volts.

http://www.jameco.com/1/3/linear-3v-voltage-regulator-ic

Look for the $4 one..

Greg



**** Habilis said:


> I'm looking for a method to flicker the two leds in a Bachmann Heisler firebox. I have removed all of its electronics so as to place a battery (14.8v) and a RailBoss 4 receiver into the tender. The flicker circuit was on the removed Bachmann board unlike, for example, the Shay which is in the firebox and was easy to wire direct to battery voltage.
> 
> I haven't found anything suitable after a bit of wandering the internet so I thought I ask for suggestions here. Thanks for any approaches that you can offer-up.
> 
> ...


----------



## Dan Pierce (Jan 2, 2008)

There are 12 volt yellow and red leds available that have built in flashes.
I would have a 12 volt yellow always lit led with a flashing yellow and flashing red in the firebox. Works well.


----------



## Homo Habilis (Jul 29, 2011)

Thank you all for your responses.

I received the following from Del Tapparo of G-Scale Graphics in his reply to an email that I sent to him directly.



> The proper way to do it would be to use a 3V regulator chip, which in theory also requires a couple of capacitors for stabilization, but you could get away with none. http://www.digikey.com/product-detail/en/LP2950-30LPR/296-31454-1-ND/3505909
> 
> If you want to try hacking in a resistor (trial and error), I would try 300 ohms, 1W.


Assuming that no one offers up a different method of providing the flicker I'll probably order both the regulator chip and an assortment of resistors and "hack" away with some tea light chips as Del suggests.

Thanks again.


----------



## East Broad Top (Dec 29, 2007)

I used these in a Shay after I gutted the electronics:

http://www.modeltrainsoftware.com/flickering-fire-kit.html

I ordered the 9v-powered ones by accident, so I put two of them in series since I was using a 14-volt battery. That actually turned out to be the bettery way to go, as the "flicker" from just one set was a little slow to be convincing for a firebox. Two in series gave a faster flicker. 

Later,

K


----------



## Greg Elmassian (Jan 3, 2008)

Yes, as I said earlier "get a regulator"... sorry it was not clear from the previous sentence that it should be the same voltage as your batteries, 3v.

As the datasheet states, ( http://www.ti.com/lit/ds/symlink/lp2951.pdf ) you should have bypass caps, and as Del states you can probably get away without them, but I'd get the little 1 mfd caps and put them on, why risk having to pull something apart for a buck's worth of caps?

Regards, Greg



**** Habilis said:


> Thank you all for your responses.
> 
> I received the following from Del Tapparo of G-Scale Graphics in his reply to an email that I sent to him directly.
> 
> ...


----------



## Homo Habilis (Jul 29, 2011)

Kevin:

I sort of discounted using the flickering leds since I'd have to replace the existing non-flickering ones in the firebox. I have no desire to take the Heisler apart enough to do that other than as a last resort.

Greg:

I just received the 3v regulator in the mail and will wire it up hopefully this coming weekend.


Just as a note, not all tea light candles are created equal. It appears that the latest cheap ones just use a flickering led and do not contain a separate circuit. I was lucky that I had a older set lying around the house that did contain the board. So, two of them have been "re-purposed" to provide the flicker that I desire. Everything works so far using a 3v battery pack external to the loco. 

I'm a basement dweller and the layout is a bit lower than eye-level. Having this flicker adds a bit to the realism and I'm glad that I'm expending the effort to make it work after removing the Bachmann board. 

Again, thanks to all for their responses and advice.


----------

