Re: Wiring LEDs to a DPST Switch
Vollrath, Don <dvollrath@...>
My mistake Rich.toggle quoted messageShow quoted text
For the RED LED, the cathode of the diode connects to the LED and the anode connects to the resistor and switch terminal. It is backwards in my description. But I think you have the resistor on the wrong side of the switch. It must be in the path to restrict current through both LEDs. It sounds like you are also trying to get them powered from DCC track power... Right? If so, there should be yet another diode to protect the LEDs from reverse voltage. I've put a connection drawing (worth a thousand words) in the files section. Look for RRampmeter LEDs.pdf Aug 29. It shows 2 diodes in series with the Red LED, just in case you have a high V green and low V red LED.
The Green LED will be on when it is safe to remove the RRrampmeter. Red when you are using it.
From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of richhotrain
Sent: Saturday, August 29, 2009 9:40 AM
Subject: [WiringForDCC] Re: Wiring LEDs to a DPST Switch
--- In WiringForDCC@..., "richhotrain" <redking56@...> wrote:
Over night, I had a chance to review my wiring and to review my prior message on this thread.
Here is the current status of my efforts. I can get the green LED to light when the switch is turned on, but I get no light from the red LED at any time.
I wired the circuit as follows: The cathode side of both LEDs are soldered together and wired to the (-) supply. The anode side of the green LED is wired to the NO switch pole with a resistor wired between the LED and the NO switch pole. The anode side of the red LED is wired to the NC switch pole. Between the Red LED and the resistor on the NC switch pole side, I wired in a 1N4xxx diode with the cathode side facing the resistor.
What am I doing wrong? Incidentally, I double checked the red LED and it is operative (not burned out).
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