What is the reverse voltage or the backward voltage in the LED that the voltage supply needed to overcome in order to allow LED to be in ON state? For example the
![Voltage Current Measurement | Voltage Measurement Display | Current Voltage Indicator - Voltage Meters - Aliexpress Voltage Current Measurement | Voltage Measurement Display | Current Voltage Indicator - Voltage Meters - Aliexpress](https://ae01.alicdn.com/kf/H34ce17c7ec6e47c3872faf01e0224ea27/Square-LED-digital-display-three-digit-display-voltage-and-current-Hertz-meter-signal-combination-table-indicator.jpg_Q90.jpg_.webp)
Voltage Current Measurement | Voltage Measurement Display | Current Voltage Indicator - Voltage Meters - Aliexpress
![New 2 Wires Dc Digital Display Voltage Table Head 0.56 Inch Led Numeric Voltmeter Dc4.5v-30v - Integrated Circuits - AliExpress New 2 Wires Dc Digital Display Voltage Table Head 0.56 Inch Led Numeric Voltmeter Dc4.5v-30v - Integrated Circuits - AliExpress](https://ae01.alicdn.com/kf/HTB1D2U9aqSs3KVjSZPiq6AsiVXao/New-2-Wires-DC-digital-display-voltage-table-head-0-56-inch-LED-numeric-voltmeter-DC4.jpg)