Hi i need to reduce voltage of a 4.2v protected battery which is in a circuit. I need the output to be 4.1 or below it .. Also it's not important to do it by not fully charging battery. Any simple solution?
Yes exactly, idk why , maybe protection circuit is broken but that battery exxceds 4.2 easily . I need a solution to prevent that from happening.(by not letting it to charge to 4.2 for example )
Old-fashioned and simple way could be LM3914 and using one of outputs to trigger whatever circuit or function. I think supply current is 'high' for battery-powered circuits.
I am harvesting energy from an NFC device using a tuned antenna on my PCB. Through this method, I am able to generate about 3.05V. I would like to charge a super capacitor using the power harvested...
Not so simple parts-count wise, but as precise as might be desirable - Op amp clamp used to drive homebrew LDO. Or maybe op amp + adjustable Vref + MOSFET constant current source circuit used to limit Vout to 4.1V.
Vref (or Vref driving resistive divider) + comparator(s) is more configurable homemade version of LM3914 with much lower Iq.