Make 7805 Voltage Regulator From BC547 Transistor | How to make 7805

In this project, we are going to create a step-down voltage regulator using a BC547 transistor and a resistor voltage divider circuit. The voltage regulator will be able to lower the voltage from a higher input voltage to a stable, lower output voltage.

7805 Voltage Regulator From BC547

The BC547 transistor will be used in a common emitter configuration, which means that the input voltage will be applied to the base of the transistor, and the output voltage will be taken from the collector. The resistor voltage divider circuit will be connected between the input voltage and the base of the transistor to provide a lower voltage input to the transistor.

By using the some basic components I am going to make 7805 Voltage Regulator we need for making this circuit.

  • BC547 Transistor
  • 47K Resistor
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By adjusting the values of the resistors in the voltage divider circuit, we can control the output voltage of the regulator. The output voltage will be stable and regulated, even if the input voltage changes.

To build this circuit, I am providing you a schematic diagram:

7805 Voltage Regulator

This DIY voltage regulator can be used in a variety of electronic projects where a stable, lower voltage is required, such as powering microcontrollers, sensors, or other low-power devices. It is a simple and cost-effective solution that can be easily built using common electronic components.

By the way you can also watch the making video:


  1. You have absolutely no understanding of electronics. You have no idea what 47k resistors will do on the base of a transistor. You have to understand that the transistor will effectively reduce the resistance of the 47k by 100, making it equal 470R and it just like putting a 470R in place of the transistor. The resistor will pass 10mA. This is something that no-one has mentioned before. But in your circuit there is another 47k and this will reduce the effectiveness down to 5mA. This is how to analyse this circuit in your head before doing any calculations and shows how absurd your circuit is.
    See my website
    Colin Mitchell


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