I'm looking documentation about this circuit. But I'm not able to find about it because I do not know the word associated to this circuit.

enter image description here

I would like to have a document which explains all the different steps in function of the time of the circuit.

Also, if you have a book to recommend me about power electronics, it would be a pleasure to hear its name.

  • \$\begingroup\$ (1) Where did you find the circuit? (2) What was it supposed to do? \$\endgroup\$
    – Transistor
    Commented Dec 18, 2019 at 8:07

2 Answers 2


This topology is known as an Asymmetric bridge. It is useful when you only need unidirectional current but also must manage a free-wheel path. The classic use of this is in Switch-Reluctance drives or induction heating

3KW SR motor gate driver and simulation questions

Switched reluctance motor inverter


You need to turn both switches on to build up current. You then have two additional states available to you.


  • Turn both switches off. This exposes the coil to a negative voltage loop which will cause the current to decay quickly
  • Turn bottom switch off. This exposes the coil to a zero voltage loop as the current freewheel via to the top diode and the top switch. This reduces current ripple.

Typically the zero-volt loop method is used during an SR sector then switching to negative to decay for next phase


Both transistors are switched on at once allowing current to flow. This current is usually limited by peak current detection. On time is limited to prevent coil saturation. When the transistors are turned off inductive energy is returned to the input via the diodes. I lashed this up 2 decades ago as a way to measure coil losses. Usually the winding is a ferrite transformer primary and the secondary extracts power. Common output rectifier schemes are diode and capacitor for flyback and two diodes and choke for foward. Most power electronic texts describe two switch flyback and two switch foward.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.