IR2153 Full Bridge + 4 x EI33 from ATX 1200W

[Dzony_988]

Hi to all..

I make this shematic and in theory (If I didnt miss something) it shuld be work and give it high power with 4 x IRFP450 and 4 x EI33 from ATX power supplay without re-winding and changing anything.

Working freq. is 100KHz (7.5K + 1nF) and two of this gate drivers IR2153 are connected for Full Bridge in PSM (phase shifting modulation) which provide output voltage adjustment with trim pot. (Setting up angle of pahse shifting change voltage of primary winding of 0V to 320V).

On 100KHz for full bridge EI33 can deliver 400W and need 40 turns on primary side because of Full Bridge tipology (double number of turns on primary). For bigger power we can use two EI33 transfomers like one big transformer (each primary in series and secondaries too with GND central tap) but each transformer need only half of number of turns.

Than we can make from the outside (without transformer opening) two paralell windings of 20 turns on primary (original serial winding 20t+20t reconecting in central tap) and connect with two parallel windigs on second transformer to make serial conection of two paralel primary windings.

Two of this gropu of transformers are conected now in parallel for double-doubled power (4 x 300W = 1200W), with separated two caps of 2.2uF for output of the transformers. (This caps are here becase EI33 dont have an air gap)

Because this is SMPS without feedback, i can play with transformers like that. For protection I will make overvoltage protection and overcurrent protection with current sens transformer on primary side, but that is for future.

What do you think, can it work and be powerfull?

Thanks and regards, Nikola
Attached Files

 

[KX36]

You can't put the secondaries of 2 (or 4) transformers in series with their mid point centre tap as ground in a 2 diode rectifier. Each half of a rectified centre tapped winding only conducts in one direction and the imbalance will cause both transformers to build up flux and saturate. You should still be able to combine the secondaries of 2 transformers, just not like that. At a minimum change to your schematic, the secondary rectifier diode pairs could be swapped for bridge rectifiers.

The rest doesn't look too bad, although I can't comment on your part values or the phase shifting implementation.

You may not need gate resistors/diodes on the FETs as IIRC, the IR2153 has a rather high ouput impedance (in the order of 100-150 ohms) so it probably can't really output fast enough edges into a FET to cause its parasitics to ring like most gate drivers can. Haven't had a chance to test that myself.

 

[Dzony_988]

Transformers must be conected just like on schematic (one group of two transformers in series and two groups in parallel. Can I connect Group A secondaries in series with group B secondaries and make central tap? But group A and gropu B have to go in parallel connection.resistor

Diodes and gate resistor is for max death time because IRFP450/60 has high input capacitance.. Result wolud be 5% lower woltage on output and quazy sine input signal who provide better transformer preformanses, low temperature and higher power because transofrmer is cold on 100KHz

 

[KX36]

The problem's with the rectifiers. e.g. you have diode - A1 - A2 - diode. both diodes conduct simultaneously in one direction, but there is no conduction through those transformers in the other direction, so it's impossible for the volt seconds in to balance in both directions for a given transformer. If volt-seconds can't balance, the transformer will saturate and things will start to burn up.
You may be able to put 4 transformers in a series/parallel configuration, but you need to change the rectifiers to bridge rectifiers so that current can flow in both directions through each secondary.

I'd also put the negative inductor in the negative rail rather than ground and if it was a regulated power supply, wind both inductors (with the correct phase) on a single core for improved cross-regulation between positive and negative rails; but that's optional.

 

[AnthonyRF]

Hi to all..

I make this shematic and in theory (If I didnt miss something) it shuld be work and give it high power with 4 x IRFP450 and 4 x EI33 from ATX power supplay without re-winding and changing anything.

On 100KHz for full bridge EI33 can deliver 400W and need 40 turns on primary side because of Full Bridge tipology (double number of turns on primary). For bigger power we can use two EI33 transfomers like one big transformer (each primary in series and secondaries too with GND central tap) but each transformer need only half of number of turns.

Hi, why you have to double the number of turns on primary for use the EI33 transformer en FBT? I'm asking that because is the only transformer avaliable here