#12v low battery indicator circuit driver
#12v low battery indicator circuit full
#12v low battery indicator circuit download

If all the ten LEDs (LED1 through LED10) glow, it means voltage level of the battery is full 24V. If, say, LED1 through LED9 start glowing, it means voltage level of the battery is around 90% of 24V, that is, around 21.6V. To see the battery voltage level in bar mode, flip switch S1 towards 24V position and turn switch S2 on. If LED10 glows, it means the battery is fully charged. If, say, LED9 glows, it means voltage level of the battery is around 90% of 24V, that is, around 21.6V. To see the voltage level in dot mode, keep switch S2 open. If you want to check the level of a 24V battery, connect it to the circuit using the crocodile clips and flip switch S1 towards 24V position. The last LED (LED10) will glow at 24V.Īfter this calibration the circuit is ready to use. The first LED (LED1) will start glowing at 2.4V and the second (LED2) at 4.8V, and so on. Now increase the input DC voltage slowly to 24V and observe the LED’s glowing status. Adjust preset VR1 such that LED1 just starts glowing. Connect 12V from the variable power supply in place of 24V battery in the circuit. And you may use a 30V variable power supply instead of the 24V battery for calibration. Use presets VR1 and VR2 to calibrate the circuit. Position of switch S2 will depend on whether you want a dot display or a bar display. Flip switch S1 for checking a 24V battery’s status. Connect red clip to positive terminal of the battery under test and black clip to its negative terminal. One of the clips could be red with red wire soldered to it and the other black with black wire soldered to it. To check voltage level of the battery, use two crocodile clips with about 30cm long wires soldered to each. Pin 3 of IC1 is connected to positive side of 12V to operate the circuit while its pin 2 is connected to ground. The 12.1V Zener diode ZD1 is used along with BC547 transistor T1 to reduce the 24V battery voltage to 12V.

#12v low battery indicator circuit download

5: Component layout of the PCB Download PCB and Component Layout PDFs: click here 4: Single-side PCB layout of 24V/12V Battery Voltage level indicator Fig. For showing the voltage level in dot mode, simply open switch S2. For showing the voltage level in bar mode, connect pin 9 of the IC to positive terminal of the battery using switch S2. This display can be set in dot mode or bar mode. The LED display comprising LED1 through LED10 shows voltage level of the 24V or 12V battery selected. 3: Circuit diagram of 24V/12V Battery Voltage level indicator

#12v low battery indicator circuit driver

It is built around IC LM3914 dot/bar driver IC1, 1N4007 diodes D1 and D2, ten 5mm LEDs (LED1 through LED10), 12.1V Zener diode (ZD1), BC547 transistor T1, BC557 transistor T2, presets VR1 and VR2, and piezo buzzer PZ1. Circuit and WorkingĬircuit diagram of the battery voltage level indicator is shown in Fig. In dot mode only the last LED representing the voltage glows while in bar made all the LEDs up to that LED glow. Switch S2 helps select dot mode or bar mode display. Switch S1 is used to monitor either 24V or 12V battery. When all the LEDs (LED1 through LED10) are glowing, it means the battery level is 100% and it is fit for use. With LED2 also glowing it means the battery level is 20%, and so on. 2: Block diagram of 24V/12V Battery Voltage level indicatorĪs shown in the block diagram, when LED1 alone glows it means the battery level is only 10%. 1 while the circuit’s block diagram is shown in Fig. The author’s circuit rigged on a breadboard is shown in Fig.