TLD2331-LM3914 smart car voltage display

Smart car voltage display based on TLD2331 and LM3914. Two LM3914 are cascaded. By adjusting the sampling resistor, the voltage can be collected and displayed through LED in 15 divisions.

Suitable for smart car competition wireless charging set. It can also be used daily to measure and display battery voltage, which is suitable for welding practice. The TLD2331 can be used to protect the LED, but the power supply range needs to be 6~8V, and the nickel metal hydride battery can be directly plugged in. When making simple production without considering the protection of LED, you can not solder TLD2331, short-circuit some pins, and then use 5v power supply. Adjusting the variable resistor can change the indicated voltage of the highest level lamp. U max =2.4*(R8/R7)V. That is to say, it is enough to ensure that the collected voltage after voltage division is less than 2.4. In order to make the tld2331 output a high level, a low level needs to be input to the control pin. The LM3914 display mode can be selected by pad shorting. The attached video is a 12v sine signal, and this project does not support negative voltage display. Negative voltage will show abnormality or even burn the IC.