bulb out indicator

Yeah thats what I figured I was just going to regulate the 12v down to 3v to make it work...and no I'm not budget restricted I had plans to put all of this in a project box to make out look more cleaner...but working with resistors and leds I have already done...I just figured the 3v need ed to go in..if 12v is ok then I'll just use resistors for the leds and wire the rest...as for the comparator I'm using all the outputs so there's nothing on the comparator that will be unused

Now for this setup..the diagram I assume is only for 1 light correct? So I would have to build that diagram for as many lights as i, want to use right...and as for the 100k resistor..that goes in between the on/off switch? So connecting both ends of the power together?

wth is this?

Sorry about that there was a bunch of spam... Anyways do you have any input on that?...do I have to wire separate ones for each light out can I use just one?...I have no problem wiring different ones just thought maybe it would be an easier way

Dang - they deleted my reply as well. Or did I change my mind...? And you said all comparators will be used, hence no problems with unused comparators (both inputs must be grounded to prevent oscillation etc). If you want multiple comparators to light the one LED just connect the comparator outputs together. (That's the beauty of Open Connectors outputs; since they switch to GND (or are otherwise "floating" so a pull-up resistor is needed to output +12V etc), ie, like a ground switch (closed when on), so parallel outputs (for LED/s etc) are merely connected together. It's the equivalent of multiple +V sources through diodes, but whereas the +V needs isolation (with diodes to prevent once source back-feeding into another), the Open-Collector or GND-switched circuit doesn't.    Are you building a twin-voltage ref comparator - ie, 0.5 Ohm and 7W bulb, & 10k resistor & (say) 390k variable resistor - with (eg) the 339 quad comparator? Or using the LT1637 circuit (and LT1637?)?

All ill be doing is building the circuit you have nd the diagram for...but I will have the quad comparator...so that way it will control 4 leds..but what I'm wondering is if the diagram you gave me is for one led does that mean that I have to build that circuit 4 times and connect it to the comparator or can I build the diagram once and have it monitor 4 lights? If the quad has 4 out puts then it will monitor 4 lights...so basically I'm building that diagram 4 times for each light

Any input?

Yes - one circuit for each comparator.

Alright thought so..thanks for all your help oldspark I really appreciate it

I just thought of something...now in the diagram its using 3v as the source...if I'm using 12v as the source does that mean all the resistors in the diagram change or is it just the 100m that changes