Low Battery Indication circuit

[crazyhorse]

I wish I could figure out how to put one of these things on my wife's 14500 ½" copper tubing mod. I rotated her atomizer last night and she said the clean one was no good. I checked her voltage. 2.82 volts. No wonder it wouldn't work.

[mnealtx]

No need for triggering just do in real time.

What will be determing if the voltage is above or below X or Y - that's what the other LEDs are for. 2 in series giving a rough voltage reference (rather like a zener diode).

Ok...but if it can be done by using a channel of the op-amp, why use the extra components and waste power that could be used for vaping?

Does that make sense?

[kinabaloo]

I wish I could figure out how to put one of these things on my wife's 14500 ½" copper tubing mod. I rotated her atomizer last night and she said the clean one was no good. I checked her voltage. 2.82 volts. No wonder it wouldn't work.

Hi crazyhorse; check out the meerschaum threads.

[kinabaloo]

Ok...but if it can be done by using a channel of the op-amp, why use the extra components and waste power that could be used for vaping?

Does that make sense?

The opamp is the smart way, dont need extra LEDs, but would need a small board.

[mnealtx]

Edit to add.... I think we fell into the 'complexity trap'!!!

Ch 1 - green led, on above 3.4v
Ch 2 - red led, on below 3.9v

That gives you the green at 3.9v +
Yellow between 3.9v and 3.4v
Red below 3.4v

Would that not provide all the necessary voltages and triggers, or am I missing something?

[framitz]

Two lead red/green LEDs that I've experienced are bipolar, so for yellow you have to alternate the polarity. An a-stable multivibrator or flip flop could server that purpose.

You're probably using three lead which is simpler for this application.

[mnealtx]

Yes, we were talking about a 3 lead (at least I was!!), but thanks for the information!

[Scubabatdan]

So could you actually have a row of LED's red being the last, and as the voltage drops the LED's go out until the red on is left?

[mnealtx]

With enough op-amp channels, it appears so. Remember, however, that the op-amp itself and the LEDs are all taking power that could be running your atomizer...