Led Driver Circuit Using Transistor

The t2 transistor can be bc547 if you use only usual leds the 20ma versions but it is recommended to use bd135 bd137 or bd139 because they have a higher power dissipation.

Led driver circuit using transistor.

Compared to the previous simple current source using two transistors this circuit has. If the led has a higher power requirement then it is best to use an npn transistor as a driver. This circuit allows you to use any voltage between 2v and 24v to drive almost any type of led with power consumption up to 5w. The future of lighting.

Therefore the transistor cannot turn on. Bipolar junction transistors need base current and sufficient positive voltage to the collector in order to provide amplification. When the switch of the circuit is open no current flows to the base of the transistor. An led driver is an electronic circuit that utilises a transistor to switch power to an led.

One typical circuit topology used to drive leds is the linear topology in which the transistor operates in the linear region. Much higher dropout of 2 4v which will significantly reduce efficiency when powering only 1 led. High power led driver circuits. Usually the signal from a microcontroller or logic gate does not possess sufficient drive current to power an led directly.