Is the LED not bright due to insufficient voltage?

Light-emitting diodes are also called LEDs. LEDs have been covered at all levels, from lighting design to indicating reminders, LEDs are involved. This article will be explained by Xiaobian for the phenomenon that the LED in the circuit is not bright. See if the reason why the LED is not bright is caused by insufficient voltage, or is it caused by too small driving current?

In this example, the total voltage of the circuit is 3V and the resistance is 580 ohms. When a 3V LED is connected in series, the LED is lit. The voltage and resistance remain unchanged. What caused the LED to not light up?

It is known from the case that since the total voltage is 3v and the resistor is connected in series to cause voltage division, this causes the resistance of the diode to be too small to reach its turn-on voltage (about 0.7v). through. Divide the resistor in parallel to the current on the diode. Do not let the current exceed the rated value. The wiring should be calculated in advance to determine whether it meets the standard. If it is not standard, you can replace it with another power supply.

There is also a convenient way to illuminate with a red LED, because the red LED voltage is relatively low and is easier to illuminate. But this method does not solve the problem fundamentally. Therefore, it is especially important to be fully familiar with the tube pressure of LEDs.

Tube pressure of various LEDs:

Red and yellow are generally 1.8 to 2.2;

Blue-green is generally 3.0 to 3.6;

Ordinary LEDs have a positive bias voltage drop of 1.6V, yellow of about 1.4V, and blue and white of at least 2.5V. Working current is about 5-10mA

Super bright LEDs are mainly available in three colors. However, the voltage drop of the three LEDs is different. The specific voltage drop reference values ​​are as follows:

The red LED has a voltage drop of 2.0--2.2V;

The voltage drop of the yellow LED is 1.8-2.0V;

The green LED has a voltage drop of 3.0-3.2V;

After fully understanding the tube pressure of various types of LEDs, you can solve the problem by encountering LED defects caused by insufficient voltage. This paper draws the importance of LED tube pressure by analyzing a case. I hope that after reading this article, friends who have problems in this area can get satisfactory answers.