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Power device with higher voltage battery and still get battery reading (lemmy.world)

submitted 1 year ago* (last edited 1 year ago) by LazaroFilm@lemmy.world to c/askelectronics@discuss.tchncs.de

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I want to power this board with a 14v battery. The board has a 1s battery connector that can power the board and read the voltage via ADC. Is there something I could place between the two to lower the voltage and still have a battery voltage reading? I would not be charging the battery through this. The usb port would not be open in the final product.

My understanding is that voltage splitting with resistors is not recommended for powering. And a buck converter will only give constant voltage reading.

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[–] elDalvini@discuss.tchncs.de 3 points 1 year ago (1 children)

You could use a voltage divider followed by a unity-gain amplifier to lower the output impedance, about like this: (I think that circuit could work, but I haven't thought about it a lot, so it might not)

[–] LazaroFilm@lemmy.world 1 points 1 year ago

Thanks for the pointer. Looks like a buffered voltage divider is the way to go. Now down the rabbit hole I go! 🐰🕳️