Can I use discarded decoders for lighting bldgs/cars?

[Fawlty Logic]

I have heard that one can use the lighting functions of discarded old loco decoders (Lenz100s for example) to control lights in passenger cars and buildings etc.

I would be grateful for any tips/directions/links to this process.

For a buidling/diy track signal bridge, how would I connect them to the power source?  Would I run a lead to a drop feeder from the track?

I do not use function decoders.  Could these old motor decoders be controlled like a function decoder connected to my Zephyr or would I be assigning an address as if it was in a loco?  I am clueless here as I haven't bothered at all with learning about this function decoders through the zephyr.

 I can see easily how to use the old motor decoder for a light function in rail car with wipers etc.  What is an economical way to light them up?  I see some light bar sets from Walthers etc. that see a little pricey.  What about wiring some small LEDs in series? parallel?

Thanks for any info. 

 

[wjstix]

I believe whether it's a function decoder or a mobile one, you still have to assign it an ID no. so your system knows who to send the signal to.

[MisterBeasley]

First I have to ask:  Why were these decoders discarded?

If people were just tossing them because they were upgrading to sound (or BEMF, or whatever) then sure, they should be fine and you can use them.  But if they were tossed because somebody toasted the light functions, well, then the light functions are no longer useful.

If they have bad motor functions, you can still use the light functions.  However, you'll have to play games with resistors across the leads to program the address.  A motor decoder in general can not be programmed without a motor attached to it.  That's true regardless of whether the motor function still works or not.

And, please don't use your precious DCC power for running lights in buildings, or anything else stationary.  That's a job for toggle switches.  Even though light bulbs only draw a little bit of current, when you put a few of them together to light a structure, it adds up pretty quickly.  It only takes a few grain-of-wheat bulbs to equal the current draw of a locomotive, after all.

[Fawlty Logic]

Thanks gentlemen.  Yes, Mr. B. you would be correct.  I would need that resistor for loco load, partic. with those Lenz 100s which don't show up on my zephyr without a resistor AND a motor anyway.

But what if used LEDs instead of incandescent in the buildings?  I think they are a little bright, but I could shield them with something I suppose.  Could I then leave them on and wired to track power?  In my partic. layout it would be far easier to connect across to a track than to run another power lead all the way out from my supply. 

LED draw adds up, if I had dozens and dozens on, but a dozen or so on?  Is that a significant draw in your experience?

[richg1998]

In my experiences, LEDs run fine at 10ma. Most LEDs are rated for 20ma max. You can play with the resistance for brightness. There are 1.5 micro lamps that work ok 10 to 20ma. Again, experiment. Very easy to calculate power requirement. Again, you are drawing from the DCC controller. If you have a booster, maybe ok. Running two wires for power with a resistor for each LED or 1.5 volt micro lamps is easier than installing a decoder. You also have to solder the wire to the track.

Inverted cone LEDs are very nice for structures. They emit light 360 degrees.

Rich 

 

[mfm37]

Old loco decoders can be used as function decoders but will need a load across the gray and orange wires while programming. A 12 -16 volt bulb would do the trick.

There are a couple of additional items to understand though.

1. Each loco decoder's address will use up one loco address memory slot.  Function decoders also use a loco slot. Accessory decoders do not tie up a slot as they are not treated as loco decoders.

2. They use "expensive" DCC power to run the accessory.

Use old loco decoders for passenger car lighting and end of train devices. Use accessory decoders for building lighting, etc. (stuff that doesn't roll on the rails) 

Martin Myers 

[jeffrey-wimberly]

 Don't use your DCC power to run anything you don't absolutely need or you may find yourself with a power falloff when you need the power the most. If you feel you must have off track lights run by DCC power use an old Bachmann system for them and save the power of your primary DCC system for your trains.