Re: lucky MOSFET find

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dan Strother" <dstroth-at-hotmail-dot-com> 

That's a nice find... Those would do well in a system operating at no more 
than 120VAC in (170VDC). Steve Ward ( http://www.hot-streamer-dot-com/srward16/ 
) has used IRFP260Ns (200V 46A) with great success in an h-bridge 
configuration.

If the gate capacitance is that high, they may not work well in the 
plasmasonic board. However, according to the IXYS site, most of their 
MOSFETs in that range have typical gate capacitances of around 5000pF, 
about half the capacitance of the 32N60s Dan M uses.

It probably would not hurt to install them and observe the gate waveforms. 
Just watch for heating in the MOSFET driver chips and whatnot.


Dan Strother



Original poster: Finn Hammer <f-h-at-c.dk>

>Gang,
>
>Just as the human eyes adjust to the conditions of the available light,
>they adjust to spot the contour of parts that are needed for current
>projects.
>Like today, when I took a stroll on the local scrapyard, and suddenly
>found myself staring at a heap of IXYS IXTN79N20 MOSFET`s carefully
>removed from what appears to be working equipment.
>
>I grabbed 30 pcs. and wondered if they could be made to do service in an
>audio modulated SSTC, for example.
>
>They don`t appear on http://www.ixys-dot-com
>but from the type markings they appear to be 79A 200V types.
>In the unloaded state, the Gate-Source capacitance is 17.7nF, but this
>might change.
>
>How do i test them?
>
>I tried hooking one sample up to a motorcycle lead battery, and apply 12
>volts to the gate, that caused current to flow, so that the isotop
>casing got hot, didn`t break it.
>
>But there has to be a better way, and I don`t want to break my
>Plasmatronic board by just plugging them in, to see what happens.
>
>Cheers, Finn Hammer
>