Half bridge Vs full bridge smps supplies

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Thank you!! actually that's what i tried to do first... to read.....but as the time passed i got confused with what to read first and now im so mess up... so now the problem is where to start reading... whole of my interest came out from designing smps for car amplifier.. and i want to design efficient one and that's where my question came from..!!!
 
I really do not understand why everybody are saying that full bridge are for high power.
Let put it this way, full bridge is a little more complicated and a little more expensive, but is certainly give you more watts/cubic inch. Why? because for the same output power, the half-bridge needs twice the amount of copper in secondary winding. For a lot of applications, you have to use a larger ferrite core just because of that. Half -bridge = half voltage in primary winding => twice the windings for secondary than full bridge for the same output voltage&current. Full bridge is more efficient in using magnetics
 
eh, you only need 1.41 times as much copper for the same watts lost in the secondary over a full bridge rectifier output. but the diode losses are doubled with full bridge. depending on what efficiency you're trying to hit and the secondary voltage a center tapped secondary with 50% more copper is better.

If you're driving the transformer with a capacitor in series then the full bridge lets you use a cap that's rated to say 5% of the dc bus. for example, I actually used some 6.3vdc 1200uF caps back to back in a 2 kw full bridge inverter recently. The duty cycle is locked at 50% so the caps only have a couple volts on them, there is no need for using quite a few cubic inches of film caps.

On the primary side it don't matter half bridge or full bridge. You might be thinking of push-pull, which is analogous to the center tapped, two diode rectified secondary. For the push-pull you'll need 41% more copper on the primary side as well.

Half bridge is often the choice because you only need one 2$ gate driver instead of two. realistically its exactly the same.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.