constructing an efficent gate drive transformer

so, I am currently working on a sstc (schematics : http://kaizerpowerelectronics.dk/wp-content/gallery/2009_03_15_-_kaizer_SSTC_II/KaizerSSTCIIdriver.gif )

I am almost finished, but the the gate driver transformer is yet to be buildt.

The gate drive transformer is going to isolate the low voltage side from the high voltage side, but i cant seem to find a lot of resources on how to construct a efficent one.

I was wondering if i could get some tips/leads on how to construct one.

Thanks for eny help

michaelkellett over 9 years ago

Don't try to build one - buy one.

Unless you have a lot of experience and suitable HV test gear you can't make a safe one.

They are not (very) expensive.

Are there any spec details associated with the design you are working from ?

MK
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magnus2112 over 9 years ago in reply to michaelkellett

her is the high voltage side: ( http://kaizerpowerelectronics.dk/wp-content/gallery/2009_03_15_-_kaizer_SSTC_II/KaizerSSTCIIbridge.gif )

Specs, this is what i found:

Bridge

4x IRFP460 MOSFETs in a full bridge configuration.

Bridge supply

0 – 260 VAC from a variac, 8 A rectifier bridge and 1500 uF smoothing capacitor.0 – 365 VDC on the bridge.

Primary coil

115 mm diameter, 1.78 mm diameter isolated copper wire, 8 windings.

Secondary coil

110 mm diameter, 275 mm long, 1000 windings, 0.25 mm enamelled copper wire.

Resonant frequency

Self tuning at around 250 kHz.

Topload

100 mm small diameter, 240 mm large diameter, toroid.

Input power

Continues Wave mode: 2000 – 4000 Watt at 200 VAC input voltage.
Interrupted mode: 100 – 2000 Watt at 260 VAC input voltage.
Audio modulated mode: 300 – 400 Watt at 150 VAC input voltage.

Buy one? You mean somthing like this one?:

Transformer Gate Drive 980UH MPN HM42 30002LFTR Bi Technologies | eBay

michaelkellett over 9 years ago in reply to magnus2112

The spec doesn't make any sense to me - 115mm diameter is HUGE - and you don't ever measure wire by its diameter.

The Ebay transformer will kill you.

For mains isolation you need a transformer where the primary and secondary are on two different sections of the bobbin or wound with a decent thick and strong insulating layer between them. The transformer in your Ebay picture relies on the thin insulation on the wire and would not be safe. A decent mains isolating transformer will be flash tested to 4kV.

There are some here that might do - they quote an IEC spec for isolation but also 600V AC working voltage so they should be OK.

https://www.grupopremo.com/147-pi-series-pulse-transformers

Farnell/E14 probably have some as well but since they broke the search engine I can't find stuff like that any more.

MK
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Robert Peter Oakes over 9 years ago

I think he is building a Solid State Tesla Coil, the kind you see in shows where the arcing is in sync with music and other things, hence coils needing to be so big I think... And yes if misshandled it will easily kill you
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