I did a quick search on here and didn't find much, but what I want to do is build a 3 digit digital voltmeter and make it relatively small.
The biggest requirement of it that seems to be an issue is that it has to be powered from the source it's measuring without materially affecting the measurement. Ideally the effect of the voltmeter using the source would be less than ~50mV of the measurement.
Everything I've seen so far needs a regulated voltage source to run the logic or MCU of the circuit and I need to somehow use the source I'm measuring to do this rather than an external source.
APPLICATION: I want to use it to hook up to my motorcycle battery and mount the display somewhere easily accessible so that I don' have to take my bike apart to check the voltage after it's been sitting. If I can get a reliable working ckt though I'd like to use it for other applications I have in mind as well.
Any input is appreciated!
The biggest requirement of it that seems to be an issue is that it has to be powered from the source it's measuring without materially affecting the measurement. Ideally the effect of the voltmeter using the source would be less than ~50mV of the measurement.
Everything I've seen so far needs a regulated voltage source to run the logic or MCU of the circuit and I need to somehow use the source I'm measuring to do this rather than an external source.
APPLICATION: I want to use it to hook up to my motorcycle battery and mount the display somewhere easily accessible so that I don' have to take my bike apart to check the voltage after it's been sitting. If I can get a reliable working ckt though I'd like to use it for other applications I have in mind as well.
Any input is appreciated!