I'm planning on making a switch bus to control lighting (cold cathodes, etc). The switches are simple vandal resistant push button alternate action switches. I want the LED to turn on when the switch is pressed and the lights are on and off when the switch is pressed the 2nd time to turn off the lights. I'm guessing it would be best to wire the LED for each switch in parallel with the inverter/cathode. That would mean putting the (+) leg of the LED after the switch but before the inverter/cathode and the ground leg with the ground of the inverter/cathode. But that can be messy for wiring especially since my cathodes have already been wired neatly to plug into a molex and go. Can I ground the LEDs by having their ground leg connected to my aluminum case chassis? Would that still keep the LED in parallel to the inverter/cathode? The (+) leg would still be between the switch and inverter/cathode. Is that safe? And can I connect all 3 LEDs' ground to one wire and then that wire to the case? This grounding method reminds me of those rocker switches with built in LED - 3 prong (1st for power in, middle for power out, and last for LED ground which connected to the chassis). Below are diagrams for grounding directly back to psu and grounding to the case.
It's probably not a very good idea to attach the LED to the case, even if the case is grounded. Is it really that hard to get the cathode of the LED to he ground of the inverter? It already sounds like the switch will be inline with the inverter, so another connection shouldn't make that much of a difference. Also, you forgot to put a resistor for the LED. Wire it straight up to +12v and you'll fry it in a millisecond (ok, maybe not quite that fast).
Don't worry, there will be a resistor - I just left that out because I was in a hurry with the diagram. It would be sort of a pain to get the LED ground to the inverter ground wire because that is directly attached to the molex, etc. I want to keep everything clean and minimize wires. I guess I could make a pass thru molex for the ground that will fit between the inverter molex and the psu.
