Thursday, September 1, 2016

12V/1A Regulated Power Supply Circuit Based on Transistor 2N3055

Electronic Kit School. - Usually semiconductor IC designed for voltage regulator like LM78xx and other have low current output. But although it is work with low current output, this component can produce constant voltage and current in it's output.

Maybe do you ever how to produce regulated power supply with high current over 1A with using this component? It is sue need additional component to produce this current output higher.

In this article we will give you one circuit that can produce 12V/1A regulated power supply based on transistor 2N3055 like in Figure 1 below. In this circuit we not used LM7812 to produce 12V output, but in here we will use zener diode 12V for stability of output voltage.


Figure 1. 12V/1A Regulated Power Supply Circuit Based on Transistor 2N3055

Component Parts

  1. Transistor 2N3054
  2. Transistor 2N3055
  3. Zener Diode 12V
  4. Diodes
  5. Transformer 12V-Ct-12V, 5A
  6. Capacitors
  7. Resistors
  8. Fuse

Circuit like in Figure 1 above show you about the 12V/1A Regulated Power Supply Circuit Based on Transistor 2N3055 that can produce regulated voltage output with 12V regulated voltage and 1A output constantly using tansistors.

From Circuitstoday site that also publish this circuit describe that transistor Q1 and Q2 form a darlington pair. Resistor R1 2k2 provides the base current for Q1 and also keeps the zener diode D3 12V in the active region. The overall working of the circuit can be demonstrated by explaining two situations.

When the input voltage (output of the rectifier section) increases, the output voltage of the regulator (Vout) also increases. This increase in Vout decreases the base emitter voltage of Q2 because the zener diode D3 is operating in the breakdown region and the voltage across it is unchangeable. This decrease in VBE increases the collector emitter resistance  of Q2 and so the output voltage (Vout) gets reduced accordingly.

When the output load increases, the output voltage (Vout) gets reduced. This decrease of output voltage (Vout) makes VBE of Q2 to decrease. This reduces the collector emitter resistance of Q2 and so the output voltage gets increased accordingly.


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