10-dot LED display that can replace analog meters

Function of the circuit

Although there are more and more examples of digital display circuits replacing traditional analog instruments, people generally prefer to use intuitive analog displays except for important uses where numerical values ​​are displayed. Recently, bar displays using multiple light-emitting diodes are being widely used.

How the Circuit Works

NS's LM3914 is equipped with 10 comparators, a reference voltage circuit, and a resistor network for dividing resistors. The reference voltage is adjusted to +5V using an external voltage divider circuit. The internal circuit can divide the input voltage of 0~+5V into ten equal parts for comparison and display. When the input is 0V, all LEDs are off. When the input voltage exceeds +0.5V, LED1 lights up. When it is +5V, LED10 lights up. When the switch is turned on, a bar display can be performed. When the switch is turned off, a dot matrix display is performed.

VR1 adjustment method: Input 5.00V from the input terminal, adjust VR1 so that the LED that displays the highest voltage starts to emit light. The light-emitting diodes have been arranged into the array required for bar display. You can also arrange 10 square LEDs together. The display LEDs and circuit board have been assembled on a sound board and can be installed on the instrument panel.