Hi all, I am in the middle of adding an LED panel near the driver seat of my RV so that I can check on the status of certain doors and voltages and settings. The one I am having a little trouble with now is the duplication of the LEDs on my 3-way refrigerator. I would like to tap into one of the legs of each of 3 LEDs (circuit board is pretty small and thats about all I can get at) on the frig and then duplicate those on some new standard LEDs on my panel.

I can read diagrams pretty good and am a whiz at wiring and soldering, but my circuit design skills just aren't there.

I have easy access to transistors, caps, resistors, op-amps, and other simple stuff, and obviously I don't want to "drag down" the operation of the LEDs at the frig.
I am attaching a PDF and JPEG of the voltage measurements I have made at the frig in the different settings. Any help would be greatly appreciated.

 

It sure looks like the rotary switch is grounding the common anode led's. That would mean the led's are shown backwards in the schematic. Supplying your panel mount leds with battery power thru 1kΩ resistors, then routing the individual led cathode wires thru to the switch positions, or the cathode side of the fridge leds, should do it. The cathode should be on the lower voltage reading of the leds. The difference between the two readings being the diode drop, or the forward voltage of the led.

 

Thanks for the information, I guess I will set up a little circuit to try it out.

 

thanks nickelflipper, I tried your suggestion as a test and it worked great !!

 

Good deal. What would be interesting would be to watch if the fridge pilot goes out when in propane mode. Now that would require an op-amp circuit to amplify the flame sensor signal. Also, all the dc mode has ever done is serve up a dead battery because you forget to change back over. A blinky led for the dc mode and when the flame goes out would be great.