Power Supply Circuit With Zener Diode

However there are some rare cases of failure where there is a short circuit and very high voltages may appear at the output.

Power supply circuit with zener diode.

For a linear regulator we can take the example of a very simple zener diode based regulator. Zener diode operation please take note of the zener diode s orientation in the above circuit. The zener diode is used in its reverse bias or reverse breakdown mode i e. The simple circuit diagram is displayed below where the transistor is being used as emitter follower.

As a blogger life is miserable i can just about afford an old banger with a knackered battery. A zener diode is a special type of diode designed to reliably allow current to flow backwards when a certain set reverse voltage known as the zener voltage is reached. From the i v characteristics curve above we can see that the zener diode has a region in its reverse bias characteristics of almost a constant negative voltage regardless of the value of the current flowing through the diode. The way out of it is to use a zener diode circuit with a seris pass transistor.

All linear power supply circuits which are designed to produce a stabilized constant voltage and current output fundamentally incorporate transistor and zener diode stages for getting the required regulated outputs. However this stability and accuracy is generally good enough for the zener diode to be used as a voltage regulator device in common power supply circuit in the figure below. Some zener diodes have a sharp highly doped p n junction with a low zener voltage in which case the reverse conduction. When using such a circuit the current needed from the zener resistor potential divider must be calculated.

One of the main application of a zener diode in circuits is it can be used to obtain constant reference voltage values. These circuits using discrete parts can be in the form of of permanently fixed or constant voltage or stabilized adjustable output voltage. This zener diode power supply circuit produces constant 4 7 v dc from 10 v to 14 4 v input. As the voltage across the zener diode has always a constant for any applied voltage values above the zener voltage it can obtain a fixed voltage value in a circuit which has a variable or fluctuating power supply.

The diode is reverse. Zener diode regulator circuit zener voltage 12 6v. It provides a maximum of 100 ma for the load which is sufficient to power my small cd player in the car. Zener diode circuit for a simple regulated power supply.