H-BRIDGE , HIGH SIDE direct coupled PNP-NPN transistor driver

[areza]

Dose any one help me constricting h-bridge driver with transistors , as I don’t want to use dedicated ICs like IR21xx etc (very expensive), the h-bridge will se 220v – 260v high dc current , any advice/infos will be very helpful , thanks

[areza]

Hi everyone , after waiting for a week for a single reply !!, I come up with something, requesting all diyAudio GURU/MEMBERS to have a look on the attached diagram and comment on it, many thanks

[luka]

Hi

Why don't you just use gate trafo?

[sawreyrw]

areza,

The opto coupler is very slow and the data sheet doesn't say anything about common mode rejection which is very important for this application. In addition, where are you going to get the floating 15 volt supply from? You would be better off with an IR 21XX and they are not that expensive for what they do.

[areza]

hi luka, i have seen some of ur work , very impressive, ..... as its a 50Hz H-BRIDGE, i guess the trafo would be bulky and difficult to construct, any other alternative? thanks

[luka]

Hi

Thanks
Half bridge is the best up to 1kw if you ask me, if you would need more then full-bridge would be way to go. You could use toroid instead ETD like cores.

Transformers aren't difficult to construct at all, I had to rewind it few times.ETD like cores will be more easy to wind then toroids, but toroids are lower, if you aim to put it in enclosure that is 1HE or 4cm if you look from inside, like I will.

[darw82]

Just read slup169.pdf from TI, look at page 36, Fig 39.

The good thing about gate drive transformer (Fig 39), you'll have negative bias at turn off. That's minimizing risk of cross conduction. Just be sure you have gate drive buffer at primary side of the gate drive transformer.

The number of turn much depend on the switching frequency.

I recently use the ATX SMPS gate drive transformer, and re-wound it with 0.16mm diameter magnet wire. 30T at primary, 30T at secondary (each). Pretty good at 100khz. For exact calculation about gate drive trafo, look at slup083.pdf (page 4)

[areza]

SORRY FOR MISLEADING EVERYONE, the h-bridge is connected with a transformer secondary generating 260vdc and 2x15vdc (for 2 high side mosfet driver ), the reason I cant use transformer for gate driver cos the h-bridge is running at 50hz , at 50hz the gate driver transformer is not a option, also don’t want to use ir2113 etc cos they cost more then twice then 4 opto controlled driver stage for the h-bridge,

[luka]

Hi

Ok that is something alse. But still you can use more simple drive, like the ones you will find in slup169..., and IR2xxx wouldn't be good anyway because of this low freq.

[areza]

Hi
Thanks to JOE in SWITCH MODE (SMPS) YAHOO GROUP for a new concept I never thought b4 (cutting out the opto), here is the new PSPICE ( I m just a beginner, only 1 week ) files for those who want to try it in there simulator and point out any flaws , have fun