Sep 14, 2012 #1 7 7102 Newbie level 6 Joined Jul 13, 2012 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,386 Hi, I need a circuit for low battery indication my battery volatge is 24V. if the voltage is 23V the led in the circuit has to OFF. if the voltage is 21V the led has to switch ON. please help. thanks, 7102.
Hi, I need a circuit for low battery indication my battery volatge is 24V. if the voltage is 23V the led in the circuit has to OFF. if the voltage is 21V the led has to switch ON. please help. thanks, 7102.
Sep 14, 2012 #2 B BradtheRad Super Moderator Staff member Joined Apr 1, 2011 Messages 15,436 Helped 2,905 Reputation 5,822 Reaction score 3,028 Trophy points 1,393 Location Minneapolis, Minnesota, USA Activity points 115,635 This low-battery monitor has worked in simulation. Schematic: Values were selected so that (a) led cannot be exposed to overmuch current, and (b) circuit uses 8 mA or less when the led is off.
This low-battery monitor has worked in simulation. Schematic: Values were selected so that (a) led cannot be exposed to overmuch current, and (b) circuit uses 8 mA or less when the led is off.