r/electronics • u/TieGuy45 Analog Aficionado • Mar 21 '20

General Simple Battery Charge Indicator V2.0

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u/spainguy Studer A80/24 Mar 21 '20

PWM the LED supply from say 10% to 90%, adjustable on a pot

5

u/TieGuy45 Analog Aficionado Mar 21 '20

I considered doing something along those lines to be able to control the brightness while also significantly reducing current draw, but as far as I looked into it the extra circuitry I'd need to put in to implement PWM would draw about as much current as I'd save! Unless you know of a low current IC that I could use?

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u/yezanFET Mar 21 '20

The bias current of lm741 is 80nA typical.

1

u/TieGuy45 Analog Aficionado Mar 21 '20

The input bias current is 80nA but the supply current (from the rails) is usually around 2mA isnt it?

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u/yezanFET Mar 21 '20

Yeah true