This circuit will indicate the battery charge level, thus giving us idea when are we going to charge or replace it with a new one. Initially when a 12V (marked) lead acid battery is fully charged, the voltage is around 12.7V (100% charge).When the battery is left uncharged for period of time, it starts to loss its charge and there come a time when the battery voltage drops to 10.5 (0% charge).See table below for voltage vs battery charge.
 |
| battery voltage vs charge |
Operation summary:
When battery voltage is above 12.2V (70%-100%), all LED is on. When voltage is between 11.7V to 12.2V (30%-60%), only LED2 is on. When voltage drops below 11.7V, all LEDs are off.
 |
| indicator schematic |
 |
| LM393 pins and internal connections |
Part List:
LM393 comparator
R1 -120 ohms
R2 -560 ohms
R3 -560 ohms
R4 -12 kilo-ohms
R5 -4 kilo-ohms
R6 -2.7 kilo-ohms
R7 -2 kilo-ohms
R8 -2 kilo-ohms
D1 -5.1V zener diode
LED1,LED2 -red, orange, yellow and either LEDs
How can do with 6 volt- need help !
ReplyDelete