SMPS versus Push-Pull?

[DJ Exprice]

Which is better?
Which sounds better?
Which is safer?
Which is easier to understand?
Which is easier to use?

[Tekko]

Push Pull is a commonly used topology in SMPS designs, or did you refer to Buck/Boost converters ?

[N-Channel]

DJ,

Clarifying Tekko's post, SMPSs come in many topologies, one of which is the Push-Pull (or Center-tap Push-Pull). This topology is most often used where the input voltage is relatively low, say in the 12-36V range. The other topologies are as follows.

Single-ended:
1) Buck
2) Boost
3) Buck-Boost, or Inverting
4) Flyback
5) Forward (One- & Two-Transistor)

Double-ended:
1) C.T. Push-Pull (Two switches)
2) Half-Bridge (Two switches, meduim- to hi-power (500W-1kW), used in 120/240VAC applications)
4) Full-Bridge (Four switches, hi-power (over 1kW), also used in 120/240VAC apps).

Now, on to answering to your questions:

1) Which is better? There is no one "better" topology than all the rest. This depends on your particular application.
2) Which sounds Better? This depends on how well it was designed, the quality of the parts and the quality of the build.
3) Which is safer? The push-pull would be safer if both input and output voltage(s) are low, but if it is hi-powered, there is still danger of shorting either side.
4) Which is easier to understand? Neither. You must first unlearn what you have learned. Oh, wait, that's Yoda's line. You need to take time to understand the basics before choosing a topology.
5) Which is easier to use? See #4.

Hope this helps you understand things a little better. May I recommend a few books dedicated to SMPS design, fabrication and testing?

1) "High Frequency Switching Power Supplies - Theory and Design", by George Chryssis, (c) 1984 (1st ed.), 1989 (2d ed.).
2) "Power Supply Cookbook", by Marty Brown (part of the EDN Design series of books)
3) "Switching Power Design" (??), by Abraham Pressman, (c) 198??.

IMHO, these three books form the Holy Graille of SMPS design, and I refer to them on a daily basis.

Cheers,

Steve