I added three LEDs in series with the gate-supply to take it to one Volt. From there I can adjust it via a variable resistor up to about 15 V (overkill). This meant I could adjust the current in the pulses. Obviously necessary with something so powerful.
There's now a 20 milliOhm reistor in series with the rectified output of the transformer to the cap bank. This is really so I can easily connect a meter and get an idea of what power is going through the system.
I adjusted the pulse to be approx 2 Hz because I thought the transistor array and related parts could manage it.
There is a 10 mFd cap in series with a variable resistor across the relay coil which gives me a broader pulse if I want one.
The purpose of this pulser is to test high-current pulses to see how effective they are at desulphating.
Well it's been a god 12 hours since I connected a 150 A/h to it. The battery had been half-pulsed before by another pulser over ten days, and I took it off to do some batteries I was contracted to fix by a 2nd hand car shop.
When I connected the battery I tested the SG and all cells were nearly at the green or exactly on. Well half a day later they are all at 1260 or perhaps a bit more.
The ten days of pulsing I did before was becoming tedious and towards the end it was difficult to see any further improvement. But a short time on a high-current pulse has finished the job.
My impression is that it worked like a dream. I mean this battery now is like a brand new one in terms of the SG and the plates look good.
I've run out of batteries which are sulphated, but I've got a few I did several months ago which I can try with this new machine.
I'll see if I can find a couple of dumped batteries tonight in the small hours outside battery shops (when no one's watching).
* I wasn't using the full power of this machine, but I would guess the amperage in the pulses I tried were approaching a hundred at the leading edge.
What has been won by the brave at great cost can be lost cheaply by fools and once gone can rarely be regained and only then at great cost.