Simple Electronic Circuits For Mini Electronic Projects
Parts Used:
Resistors: (1/4 Watts)
R1 – 10K
R2 – 10K
R3 – 10K (preset)
R4 – 10K (preset)
R5 – 1.5K
R6 – 1.5K
R7 – 1K
R8 – 1.5K
R9 – 1.5K
IC:
U1 Dual Op-Amp LM358
LEDs:
Red
Green
Yellow
Fuse:
100mA
12V Battery
General purpose PCB
Circuit Description:
This circuit monitors the 12V battery voltage. It provides an indication of normal supply voltage as well as low and high voltage. RV1 and RV2 adjust the point at which the red/yellow and yellow/green LEDs are on or off. For example the red LED lights up at 11V and the green LED at 12V. The yellow LED remains on between these values.
