ron pugh replication

[Sprocket]

You can source the MJL21194 from Cricklewood Electronics in London.  It's been a few years since I ordered from them, but I found them excellent and they have really hard-to-find stuff that no others stock - recommended!

http://www.cricklewoodelectronics.com/Cricklewood/search.php?mode=search&page=1

I'm sure there are others much more qualified to advise, but I would expect that what is blowing the transistors is a large BEMF pulse from the driven coils when the transistor switches off.  However, where I would expect to see a large BEMF pulse, the pdf text talks about a large positive voltage (BEMF would be negative) - hmmm...  Since I have never wound anything bigger then single strand coils, I can't offer much more except the observation that while a protection diode is provided to cater for trigger-coil BEMF, the other coils have nothing.  Dunno...

[Ren]

Hi envisioneer,

Nice replication, looks like you have put a fair amount of effort into it. There are lots of tricks for setting up and tuning a multicoil. You only need one trigger winding and one globe etc if all coils are to fire at once. Im sorry to say I would suggest dismantling the whole circuit, it looks right at a first glance, but I cant be sure. You need to get it firing on one coil, one winding first. Once you know you have that coil and power winding firing you can move onto multiple transistors. All bases must have the same resistance but that resistance cant be too high otherwise it just wont fire. Get one running and tune it and you will have a fair idea of what base resistance to use. Reversing the trigger coil could fix your problem, if its polarity is around the wrong way it wont work.

Your right you really jumped into the deep end on this one

Good luck, Ill keep an eye on your progress

[envisioneer]

Thanks Ren and Sprocket for your advice. Waiting for replacement transistors in post to continue. Opted for more BD243C's as they're a tenth of the price of the MJL21194's and can't afford to burn up too many of them at ?4 a pop! Will also use a good charge battery to reduce complications until I'm up and running.

It's easy enough to disconnect the windings without dismantling the whole circuit so I'll start with that and keep you posted.

[Kennyg]

I know this thread is a bit old. Did you have any luck getting your unit to work properly?  I also have solar, wind and have been working on hydro. Would like to refurbish my lead acid battery banks. Been debating on something like this or a solid state device. I've been building small bedini systems for years with good luck. Nothing big enough for my 24v, 875ah battery banks. Hope to hear from you or even others who are into this.

Thanks, Ken