Is the light-emitting diode not bright due to insufficient voltage?
Light-emitting diodes are also called LEDs. LED has covered all levels, from lighting design to indication reminders, LED has been involved. I will explain the phenomenon that the light-emitting diode in the circuit does not light up, and see whether the light-emitting diode does not light up due to insufficient voltage or too small driving current?

Case: The total voltage of the circuit is 3V, and the resistance is 580 ohms. When a 3V light-emitting diode is connected in series, the light-emitting diode is not lit. The voltage and resistance remain unchanged. What causes the light-emitting diode to not light up?

It is known from the case that because the total voltage is 3v, and the resistor is connected in series in the circuit to cause voltage division, the resistance of the diode is too small, not enough to reach its turn-on voltage (approximately 0.7v), so it cannot be turned on. Divide the current on the diode in parallel with the resistor, and don't let its current exceed the rated value. The wiring should be calculated in advance to determine whether it meets the standard. If it is not in compliance with the standard, you can replace a power supply before debugging.

In addition, there is also a convenient way to use red LEDs for lighting, because red LEDs have relatively low voltage and are easier to light up. But this method does not fundamentally solve the problem. Therefore, it is very important to be fully familiar with LED tube pressure.

Tube pressure of various LEDs:

Red and yellow are generally 1.8 to 2.2;

Blue-green is generally 3.0 to 3.6;

The forward bias voltage drop of ordinary light-emitting diodes is 1.6V for red, about 1.4V for yellow, and at least 2.5V for blue and white. The working current is about 5-10mA.

There are mainly three colors of super bright light-emitting diodes, but the voltage drop of the three kinds of light-emitting diodes is different, the specific voltage drop reference value is as follows:

The voltage drop of the red light-emitting diode is 2.0--2.2V;

The voltage drop of the yellow light-emitting diode is 1.8-2.0V;

The voltage drop of the green light-emitting diode is 3.0-3.2V;


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