Increasing the power rating of zener diodes


Posted on Jul 15, 2012

A power transistor can be used to provide a high powered zener voltage from a low wattage zener. A 400 mW zener can be used where a 10 watt zener is required or a 1 W zener can be used where a 50 to 80 watt zener is required by using appropriate transistors for Ql and Q2 in the circuits shown. Where low rating is required, Ql would be an ASZ 15 (germanium) or an AY9140 (silicon). Q2 could be a 2N2955 (silicon). For higher powers, Ql should be an ASZ18 (germanium) or a 2N2955 (silicon) and Q2 a 2N3055 (silicon) or an AY8149 (silicon).


Increasing the power rating of zener diodes
Click here to download the full size of the above Circuit.

A heatsink on the transistor is required. The circuit in A has the advantage that power transistors can be bolted directly on to a chassis which may serve as a heatsink.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Nanoampere sensing circuit
Sequential Flasher
Simple Pulse Generator
Electronic Horn
mosfet Turning a microcontroller on with a flip flop
a better sine wave
please 555 circuit
Comments on the Circuits of the first Transistor Radios
Controlling high-current circuits
Free-Electron Pump (FEP) Experiments
NE566 frequency modulator
Three-start circuit current relay



Top