Circuit that detects input voltage and turns itself on or off

Thread Starter

MikeA

Joined Jan 20, 2013
206
This is for a battery operated device. Say this circuit is connected to a lithium-ion battery pack that is 22.2v at 0% charge and 25.2v at 100% charge. If I want the circuit to turn off at say 10% (22.5v) and turn back on at say 20% (22.8v), how would I go about accomplishing this?
 

eetech00

Joined Jun 8, 2013
1,941
This is for a battery operated device. Say this circuit is connected to a lithium-ion battery pack that is 22.2v at 0% charge and 25.2v at 100% charge. If I want the circuit to turn off at say 10% (22.5v) and turn back on at say 20% (22.8v), how would I go about accomplishing this?
Hello,

Could build a simple voltage level detector

eT
 

Audioguru again

Joined Oct 21, 2019
1,596
A 6 cells Li-ion battery is 25.2V when fully charged (4.2V per cell), 22.2V (3.7V per cell) when half-charged or is in storage), and is 19.2V (3.2V per cell) or a little lower when its load should be disconnected. You want it to turn on and off when it is about half charged.
 

danadak

Joined Mar 10, 2018
4,057
Using mBlock to program a ATTINY85 or a nano board pretty simple to do
this. mBlock is a graphical programming language, you drag and drop blocks,
as shown in middle window, onto design area, right hand window, to create
program. mBlock then converts that to Arduino C like language automatically
and programs board.

1578575185631.png

Using Nano board mBlock can program that directly (thru USB port), or Nano board
in turn can be used to program a ATTINY85, procedure fairly simple and straightforward.

Note the block code not complete, a couple of blocks have to be added to convert read
A/D value to voltage taking into account its Vref and the external divider. Simple math
has to be done.

Regards, Dana.
 
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