Hello All
I have a DPDT switch which I added to my layout to operate both DC and DCC.
The wire connections are straight forward and easy to add to the switch.
I have tested the switch in both DC and DCC, they work very well.
On my panel, where the DPDT switch is attached, I would like to also add 2 LED lights, one for the DC side and one for the DCC side to light up when one of the functions is working.
I’m not sure how to go about it.
Any help and assistance would be greatly appreciated!
One way would be to wire a pair of bi-color LEDs to the center terminals of the DPDT switch. One would be lit green and one would be lit red at all times.
Rich
Hello Rich,
Is there any other way to connect the 2 LEDS, so that they are only on when the toggle is in either position, instead iof all the time?
The DC side would only be lit with a non-zero voltage, not all the time.
If the OP is okay with that, then all is good. But DC throttle “off” would look the same as DCC powered off.
To solve the DC problem, the simplest way would be to get a triple-pole double-throw switch, and use the third pole to drive the LEDs using a separate power source. The switches are a few dollars each.
Any other means adds complexity.
I would like to make something like this:
Note: two green LEDs, one for DC and one for DCC.
Can you provide a diagram of how the DPDT is currently wired?
Is it DCC on one end and DC on the other end with the rails wired to the center terminals?
Rich
Yes, exactly like you described.
seems like you would need a 3rd pole on the switch or some circuitry.
Looks like RPC Electronics DC/DCC Switch Panel is what you want ($12)
looks like the RPC board is nothing more than a 3PDT switch. That 3rd pole powers one of the 2 LEDs
I’m going to stray a little bit from the main topic to express concern for powering the same layout with two different power sources, DC and DCC.
If DC and DCC locomotives are going to operate on the same trackwork, I think that is risky even with toggle switches and LED warning lights. At a minimum, it would seem to me that at the end of each operating session, the locomotives should be parked on isolated and gapped tracks, separately for DC and DCC. At least that way when the next power up action occurs, no locomotives are “live” until the desired power source is selected and the parking track is activated.
Rich
I have no experience with triple pole, double throw switches, so I will be interested in how such a switch is wired to meet the OP’s panel requirements.
Rich
+1 [Y]
I pulled together a couple of drawings that illustrate the numbering of the 3P2T switching numbering protocol.
thank you all for your input. I will look into this type of switch as well.
722
You should indicate ballast resistances in series with that “12V” supply before he starts manufacturing smokeless DEDs. And I’d route the other side to the common associated with 12V+, not to ‘ground’ unless you’ve wired common ground appropriately for that DC circuit.
I made my first power district switchable, when I converted to DCC. I had not run it on DC since conversion. To protect against frying locos, I am the only person involved and I wrote a procedure to change back and forth. The procedure directs me to power everything down, remove ALL units from the track, then throw the big switch.
I changed temporarily to the old DC electronics today, for the first time. My DCC controller is out for work, and I thought I’d exercise some favorite locos that haven’t been converted to DCC yet.