Looking for Info 9V Cut Off Circuit.

I am looking on info on how to build a circuit to shut power off @ 9v. I am using a 12v input to power a project. I an using 18650 batteries and don't want my 3S pack to drop below 9v for fear of damaging the batteries. So i need it to shut off my projuct when this voltage is reached.

by Antairus
December 24, 2016

How much current do your batteries have to supply when operating? What's an acceptable on-resistance?

by mrobbins
December 25, 2016

1 Answer

Answer by mikerogerswsm

You need to think of this backwards. Rather than turning the power off when below 9V you need to turn it on when there is more than 9V. Pot down the battery voltage and compare it with a reference using a comparator with a teeny tinge of positive feedback. Use the comparator output to drive a bjt or fet in one of the supply leads. Hope this is helpful.

+1 vote
by mikerogerswsm
January 01, 2017

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