Hi There,
I have been researching the idea of a PWM controller - say the TL494 - to be used as the basis for a bench power supply pre-regulator.
Basic specs would be 30volt adjustable power supply with current limiting to 10Amp.
What I would like is some input as to whether I am on the right track here. I wanted to use the TL494 (or I think, SG2524) as this was also a learning curve just as much as producing a bench power supply.
The idea was to run a linear regulator after the pre-regulator such that the pre regulator would supply a voltage just above the voltage required by the linear regulator.
The second idea was to do with the type of topology for the pre-regulator. From what I can see there are three different approaches (apart from flyback, and Buck) that I can use to drive the high frequency step down transformer. I can use Half bridge, full bridge or push pull.
I thought I might use push pull as I will be winding the transformer and can add in a centre tap without too much trouble.
Adjusting the voltage level via the pulse width is the intention... feeding this into a large filter cap and then supplying the linear reg from here...
What are the reasons you would use a half or full bridge instead of a push pull topology in this regard? Is the only difference the complexity of the transformer?? or are there other reasons?
I am hoping someone who has a good idea about these concepts might tell me the answer to the above questions and also whether the use of the PWM idea as a pre-reg has merrit....
Kind Regards
Simon