Large Scale Central

DCC and an on/off switch

Electronics
#1

I all. I was just wondering if there is a way to use a function decoder as a on/off switch to turn on some animation figures I have made. The output current on the function decoders seem kind of low to operate a relay. Has anyone had any success with the decoder / relay method? What components did you use?

Thanks

Steve

#2

Many decoders will run 100 ma on the function outputs. You can find relays for that.

Be sure to put a snubbing diode across the coil.

Greg

#3

I have used relays that have the diode built in , easier wiring, check the specs.

This diode is usually in series with the coil, not across it.

Greg, do you think this makes a difference as a snubbing diode conducts/shorts the back-emf whereas a series diode just blocks the kick back.

#4

Thanks Greg and Dan, I’ll start doing some experimenting. Can you recommend a cheap, small, function only decoder? I have the NCE 10 amps system.

Steve

#5

Dan, the diode needs to be across the coil. I can go into the reasons, but a hint is reverse breakdown voltage of the diode is the issue with your suggestion.

Look it up on the internet, it may surprise you, the BEMF WILL be generated, how you handle it is important.

Function only decoder, FL4, from TCS, as long as your DCC track voltage is not too high.

Or even a TL-1, that’s even cheaper.

http://www.traintekllc.com/Function-Decoders/products/73/0/1

Greg