#Low battery indicator circuit diagram driver#

Using the S2 switch, connect pin 9 of the IC to the positive terminal of the battery to display the voltage level in bar mode. This display supports both dot mode and bar mode. The LED display, which includes LED1 through LED10, indicates the voltage level of the specified 24V or 12V battery.

#Low battery indicator circuit diagram driver#

It is constructed of an IC LM3914 dot/bar driver IC1, 1N4007 diodes D1 and D2, ten 5mm LEDs (LED1 through LED10), a 12.1V Zener diode (ZD1), a BC547 transistor T1, a BC557 transistor T2, preset VR1 and VR2, and a piezo buzzer PZ1.Ĭircuit diagram of 24V/12V Battery Voltage level indicator The figure below depicts the circuit and operation of the battery voltage level indicator. In dot mode, only the final LED denoting the voltage illuminates, but in bar mode, all LEDs up to that point illuminate. Switch S2 allows for the selection of dot mode or bar mode display. The S1 switch is used to monitor either a 12V or 24V battery.

When all of the LEDs (LED1 through LED10) are lit, the battery is fully charged and the device is ready for usage. With LED2 also lit, the remaining battery capacity is 20 percent, and so on. As depicted in the block diagram, when LED1 alone illuminates, the battery level is only 10% full.