How to Build a Zener Diode Voltage Regulator

How to Build a Zener Diode Voltage Regulator

A Zener diode is a very useful device for regulating voltage. By connecting it in the right way in a circuit, it can act as a voltage regulator, to regulate how much voltage it feeds to a device.

To connect a zener diode in a circuit to provide voltage regulation, the zener diode should be connected, in reverse biased, in parallel to the power source which gives the zener diode its voltage, with the power source connected to a resistor. In this project, we will use a 1KΩ resistor.

Below is how the circuit will be connected:

How a Zener Diode Voltage Regulator Circuit Works

The above circuit is the perfect setup to make a zener diode voltage regulator. The 12V power supply drops across the 1KΩ resistor and the zener diode. This particular zener diode in use has a breakdown voltage of 5.1V. This means that the zener diode will have a voltage drop across it of 5.1V while the remaining 6.9V falls across the 1KΩ resistor. The zener diode will maintain a steady, constant voltage of 5.1V across it.

The load that the zener diode then powers is connected in parallel with the zener diode. This is because voltage in parallel is equal. So this means that the voltage the zener diode gives off to a device (if it's in parallel) will be 5.1V.

And this is how voltage regulation works with a zener diode.

If you don't have the exact values above, such as DC voltage or the exact zener diode, experiment with others. You just have to make sure that you have a voltage that is higher than the breakdown voltage of the zener diode and a resistor to dissipate excess voltage from the zener diode, which is the purpose of the 1KΩ resistor above.

To see this zener diode voltage regulator circuit in real life, see the following video shown below.

Related Resources

What is the Zener Voltage, VZ, of a Zener Diode?

What is the Resistance, RZ, of a Zener Diode?

What is the Current, IZM of a Zener Diode?

What is the Power Rating, PZM, of a Zener Diode?

Zener Diode I-V Characteristics Curve