Hello dc42 !
Sorry about that.
1) Voltage can vary between 50 to 80Vdc (although it should be nominal at 75Vdc)
2) For each input, I need to put 1 led onboard, and 1 led in a case (that means there will be a 7 pin connector in the PCB to connect the external leds)
3) Voltage supply (75Vdc) has no power supply restrictions, (it can use far more than this board will need)
4) Reverse voltage requiered (in case its connected wrongly, or to prevent a certain channel feeding another one)
5) Negative for the 75Vdc will be common to all inputs
6) At first I wanted to use zener diode to make a clear distinction between voltages under around 50Vdc and over it. The reason was that it should be around 75, so anything lower than 50Vdc does not make sense. However, I wouldnt mind if it can detect a range like under 50Vdc (logic 0) over 50Vdc (logic 1)
7) Using SMD components (0805, 1206) so 250mW for the latest as max power dissipation I guess.
One of the two leds (the external mounted) will need to be hocked afterwards directly to ground. That way for 6 inputs I only need to extend a 7 wire cable (6 leds+1ground). If the led is between the circuit I would have to extend 2 wires for each input. Also that would make this external led necesary for the rest of the circuit to work which I dont want.
please let me know if more details are required, and thanks for looking into it.
screenshot Option1H is working correctly, but as I mentions has some problems when voltages go under 60Vdc, also the 10K resistors can not be replaced to allow more power to the led as they will get too hot.
Thanks again !