The transistors are configured as an H-bridge. This series of transistors will take 400 volts. T1 is a 1:10 step-up. T2 is the choke coils bifilar wrapped similar to the 8XA. The bridge diodes should act as the blocking diode. The CD4047 will deliver a near perfect 50/50 pulse. The only thing I’m not sure of is the value of the bias resistors for the transistors, and the overall frequencies. I plan on winding the coils on a large ferrite U core, probably with 18 gauge wire.
I was told M20 for frequencies around 10K by a mag engineer, but Stan's work is not the norm. I'm still not convinced that the core has to be thin and flat.
That is part of the beast of a schematic I have been working on for a long time deciphering the PLL resonant driver of Stan’s. Now that the high res photo’s have been released (many thank you’s to Dan) I have made better progress. Evidently the divided by’s were not used, along with several other mods. In the past I have rushed out the gerber files to get boards to work with, only to end up cutting traces and adding jumpers. Trying not to repeat that as much.
I could use some help with the PLL circuit. Pin 3 (COMP_IN) of the 4046 looks like it goes to a .35 cap then to the emitter of the 2N2222. See actached jpg.
My coils are 600 Primary, 3000 secondary and chokes. Don't have an inductance meter.
If you don't mind, can you PM me on the source of your ferrite? I have a plan to mount them if I can find some. Those bobbins were for a laminate steel setup. I have some better ones on order.
Thanks DynoDon, just wanted to make sure on the wire size. Mine is really a pain to disassemble and rewind. In his Figure 5 diagram he had a diode across the primary coil. I have done this for relays to suppress spikes, but when I add one to my driver circuit it raises the amps and everything heats up (and yes I checked the polarity). Did you see any such animal on the coil pack?
Was the primary also 29-30 guage? Thanks DynoDon, that is the picture I have been looking for. My machinist tells me he finished the test cell. I have been testing out a coil pack with laminate steel with small results.
A friend of mine wanted me to build a Meyer replica along the lines of his 8XA box. I updated the gating circuit to 4000 series chips. It only requires one power input instead of two. Two of the circuit boards should be in tomorrow to test.
Thanks Steve Couple of pics of the circuit working. The scope is hooked to the input side of the opto chip. Also is a shot of most of the 8XA setup. I am in the process of a rebuild of my WFC so I haven't hooked it up today. I believe the original unit used a post mounted SCR. I can still get one but don't know if I will bother.
Thanks Tony, I use 4047’s instead of 555’s. Got tired of the 555s going toes up and dying on me for no reason. It also lets me use a single power rail. By using a 10 volt regulator it is very stable.
I'm guesing this 555 in the Resonant Scanning Circuit, Figure 8, is set up for a 3 secound pulse. Any body know? Think that is a 10uf cap and a pair of 220K resistors.
The 1 kHz signal is separate and is just a guess for a starting point. I have not have time to test my circuit and it was drawn from memory of driving motors forward/reverse.
I have a few ideas of my own based on what info and pics we have seen. I built robots many years ago and to drive the motors I designed H bridges for forward and reverse and used PWM (pulse width modulation) to control the speed, but give full power. I’ll see if I can dig up the circuits I used. If I can get it working, think of this: Take a standard 30 gal electric water heater, build a “Steam Resonator” element to replace the 220 volt element. Hot water using a fraction of the power needs. The only thing I would worry about is leaching of chromium from the stainless. Would run some test before I hooked it into my house. It also would not be a major retrofit to replace my 5 ton propane furnace with a hot water heat system. As for now, I’m just trying to find time to work on the 5 coil VIC stuff.