[SOLVED] Detect two voltage ranges without MCU

[Tuppe]

Hello.
I'd need to make an analog circuit, that can differentiate two voltages, about 0.66v and 1.9v, and then toggle a different pin to GND for each event.

So for example:
1. I have normally 5V voltage to the input pin
2. User presses button, which drops the input voltage to 1.9V(button circuit has voltage divider)
3. Then I need to attach pin A to ground

Same goes if I detect voltage around 0.66V, but then I need to attach pin B to ground.

How complicated circuit would it be, if I need to detect e.g. 0.5V-0.7V to toggle a switch and 1.8V-2.0V for another switch?
I was able to make an comparator circuit, that detects +0.6V, but then all the buttons above that will also satisfy the condition. I'd also need to set upper limit.
Would it require 2 stage comparator circuit?

I surely know how to do this with MCU ADC, easy business, but like they say about digital circuits: anyone can count to one.

 

[barry]

You need two 'window comparator' circuits. Each circuit uses two comparators. Or you can buy something like a Linear Tech LTC1042, which is a pre-packaged window comparator.

 

[Tuppe]

You need two 'window comparator' circuits. Each circuit uses two comparators. Or you can buy something like a Linear Tech LTC1042, which is a pre-packaged window comparator.

Oh, that works out very well for the purpose. Thanks for that info, now that I know the actual term, I can now find all the info online.

Thanks!

 

[Mithun_K_Das]

use some comparators to detect the voltage level. you can get idea from here: Op-Amp Comparators