Circuit diagram of the operation of the two-color LED display voltage fluctuation

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Supply 0603 red green two-color 1615 red green two-color patch LED led light

Figure 1 is a Wien bridge oscillation circuit with three output voltages - high, low and oscillation. The amplitude of the oscillation is determined by the voltage. Use it to drive a two-color LED to display the high and low thresholds of the voltage.

When Vin is above the first threshold voltage, the op amp is in a high voltage output state, and when the input is below the second voltage threshold, the op amp is in a low voltage output state. If the input is between high and low, the output of the op amp oscillates between high and low.

With a two-color diode, the voltage is changed, for example, the green light at high voltage and the red light at low voltage can visually indicate the oscillation state of the voltage.