Understanding SM Driver Circuit, Building A Test Driver Voltage control Board


HMS-776

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #77, on December 14th, 2016, 08:53 PM »
Let me know if you guys get it working.

I've been working on my own drive circuit. I get good square waves across the primary coil but I still can't find resonance.

I have family coming out so I've got to put everything away to make space.....It might be till the new year that I get things back together to test again :(


Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #79, on December 15th, 2016, 12:58 AM »
Quote from HMS-776 on December 14th, 2016, 08:53 PM
Let me know if you guys get it working.
Well, Russ tested with actual hardware and I spent about as much time with the simulator.  With a few minor adjustments, both of us got the driver to work.  Now having said that, I'm still not real sure what Stan's driver circuit actually accomplishes.  I see a tiny spike on the leading edge when the signal turns on, but I can't say whether this is important or not.

Guess we push forward...


Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #81, on December 15th, 2016, 02:55 AM »Last edited on December 15th, 2016, 03:02 AM
And this setup gives the weirdest response I've seen so far.  Using all 5 volt drives.  Same resistor values.  Unfortunately I can't simulate a TIP120, so I'm using a TIP47 instead--your mileage may very.  Scope offsets for each channel is +/- 1 div from centerline.  And yes, that B channel is really set to 200 volts/div.  Weird aay...?

~Russ

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #82, on December 15th, 2016, 11:39 AM »Last edited on December 15th, 2016, 05:50 PM
ok i'm freed up a bit,

Ill call you after lunch Matt,

be around if you are... its faster to discuss it there than here. will post out come ( below) of our discussions.

~Russ

out come was that we want a driver circuit as identical as stans with out all the bells and whistles manual mode only!, so we diceted to trace the cards once again and make sure that fig 5 its right,

and yeah its not,

so this is the current known configuration of the VIC card driver circuit...

the extra components might only be for the PLL circuit, OR it could be apart of the feed back loop that the driver needs! we dont know but we will test it and sim it...

EVERYONE PLEASE DO THE SAME look at the photos from the estate and TELL ME WHERE I'M WRONG so we can fix it!
if we all dont agree we need to see why, and fix it...

im still not sure about the VCC voltage just yet, i need more time but its tied to the Base Voltage that the card is... im hoping its 5V. but cant seem to trace it back... it could be 10 or 12v but that dose not work in the sim of on the bench, only 5 so im guessing its 5. some one else can check that... until i get time...

give it a sim mat and see if anything funky is going on with that...
~Russ


Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #83, on December 15th, 2016, 05:57 PM »
So, Russ and I have taken a challenge to determine what the outlined components are here in this image, why they are there and to come up with an accurate Figure 5 schematic with those components in-place.  If anyone else would like to participate, by all means, jump-in and lend a hand.

Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #84, on December 15th, 2016, 06:04 PM »
Quote from ~Russ on December 15th, 2016, 11:39 AM
im still not sure about the VCC voltage just yet, i need more time but its tied to the Base Voltage that the card is... im hoping its 5V. but cant seem to trace it back... it could be 10 or 12v but that dose not work in the sim or on the bench, only 5 so im guessing its 5. some one else can check that... until i get time...
I clearly see an LM340T5 (7805) on the VIC housing.  The likelihood we are dealing with 5 volts instead of something else is pretty good, but we need to carefully trace it if possible.


Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #86, on December 15th, 2016, 07:37 PM »
Quote from gpssonar on December 15th, 2016, 06:41 PM
Why don't you guy's just use Don's sketches?
Well, they are better than the patent schematic for sure, but I'm not entirely convinced they tell the whole story.
Quote from gpssonar on December 15th, 2016, 06:41 PM
It clearly shows the +voltage going to the 47K resistor and all the way up to the + power rail that goes to all the IC chips that's on the board.
Which power rail?  12 volt or 5 volt?

So what I need is an accurate schematic to sim and build boards from.  The patent schematic is almost useless.

Nowhere have I seen before a 22K resistor acting as a feedback loop with a small disc capacitor connected to the loop pulled to ground making it an RC filter network.

Then there is the issue of the rectifiers.  The only rectifier in the photographs is a single 5 volt jobbie, so I'm guessing all of the driver circuit and even the PLL runs on 5 volts, not 12 or 10 or anything else.

My hunch is this driver circuit is a little more special than the average bear would think, so I want to get it right and have that piece of the puzzle out of the way, so we can focus on the VIC itself.  I wouldn't be all that surprised if HMS had a proper driver, his VIC would take off and run just as it is; maybe others too.  Probably not mine, but that's another story.  I'll cross that bridge when I get there.

A piece at a time Ronnie.  The closer we get to having the correct setup, the closer we'll be to actually understanding this beast.

Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #87, on December 15th, 2016, 07:46 PM »Last edited on December 15th, 2016, 08:08 PM
So Russ, I'm not fully convinced that jumper wire connected to the 22k resistor actually goes to pin 3 of the PLL (signal G).  Take another look and let me know what you think.  Looks like it may actually go to the next one up on the 5 hole block, which I is VCO Out (pin 4) instead of Comparator In (pin 3)

If this is true, then Don's sketch is not quite accurate.  And it means the feedback is on the other side of the divider network.  However, the divider network is not used at all.  Go figure that one out...


haxar

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #89, on December 15th, 2016, 08:37 PM »Last edited on December 16th, 2016, 02:37 AM
The bodge RC filter is connected:

Primary coil out lead -> 22k -> PLL pin 3 -> .33uf -> GND

This RC filter appears to be connected to PLL pin 3. PLL pin 3 is also connected to a 4001 pin 8 (@ corner of the card).
Quote from Matt Watts on December 15th, 2016, 07:46 PM
And it means the feedback is on the other side of the divider network.  However, the divider network is not used at all.  Go figure that one out...
The last output of the divider network goes to a green LED on the front panel. Output of 4001 pin 11 is used for this LED.



HMS-776

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #92, on December 15th, 2016, 10:09 PM »
Thanks for the compliments Matt, I think your right. I feel like I'm right there but my drive circuit needs more work.

I want to replicate Stan's but feel that I can get something working with less hassle  based on Ronnie's explanation....One thing I would like to see is a scope shot of the signal across Ronnie's primary coil?

~Russ

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #93, on December 15th, 2016, 11:10 PM »
ok, well to my tracing everything is jumped out to 5V  so i can see where there was place for voltages for both stages, however there jumper'd out, and its all tied back to the 5V regulator that's on board!

so my guess is that its all 5V

ill need to test if a 5V Pk-Pk works, i cant remember.

~Russ





Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #95, on December 15th, 2016, 11:13 PM »
Quote from HMS-776 on December 15th, 2016, 10:09 PM
Thanks for the compliments Matt, I think your right. I feel like I'm right there but my drive circuit needs more work.
We'll get you there if we can.  I just ordered components a few minutes ago and should have something in a week or so to confirm what we think things should look like.  I'm pretty curious to see for myself just how pure the signal into the VIC actually is.  From what I can make out, it sure looks like the PLL could be pushing the phasing around--meaning a steady square wave may not cut it.
Quote from HMS-776 on December 15th, 2016, 10:09 PM
I want to replicate Stan's but feel that I can get something working with less hassle  based on Ronnie's explanation....One thing I would like to see is a scope shot of the signal across Ronnie's primary coil?
Yes, that could be helpful.  Don't know if Ronnie scooped up that Tek scope or not someone was offering a while back.  If he did, maybe he could pop a probe on his running unit and snap a pic for us.    :whistle:

Be a good way to see what Coulombs Law looks like.    :giggle:

haxar

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #96, on December 15th, 2016, 11:13 PM »Last edited on December 15th, 2016, 11:19 PM
Quote from Matt Watts on December 15th, 2016, 05:57 PM
So, Russ and I have taken a challenge to determine what the outlined components are here in this image, why they are there and to come up with an accurate Figure 5 schematic with those components in-place.  If anyone else would like to participate, by all means, jump-in and lend a hand.
This RC filter is not in the official Figure 5 WO92/07861 patent. It is a bodge. As for the cap, I have yet to look at.

Attached is what the VIC card should reflect now.

C12 could be some other nF value.

Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #97, on December 15th, 2016, 11:16 PM »
Quote from ~Russ on December 15th, 2016, 11:10 PM
ok, well to my tracing everything is jumped out to 5V  so i can see where there was place for voltages for both stages, however there jumper'd out, and its all tied back to the 5V regulator that's on board!

so my guess is that its all 5V
Yes I think so.  It's the only regulator in there.
Quote from ~Russ on December 15th, 2016, 11:10 PM
ill need to test if a 5V Pk-Pk works, i cant remember.
It's working in my sim, but the signal at the base of the TIP120 is even more crazy.

Matt Watts

Re: Understanding SM Driver Circuit, Building A Test Driver Voltage control Board
« Reply #98, on December 15th, 2016, 11:18 PM »Last edited on December 15th, 2016, 11:26 PM
Quote from haxar on December 15th, 2016, 11:13 PM
This RC filter is not in the official Figure 5 WO92/07861 patent. It is a bodge. As for the cap, I have yet to look at.
Yes, we will have to figure out what the cutoff for the RC filter is since it tells the PLL which way to adjust the phase.

I'm not real sure about this particular PLL, but I think with no input to the comparator it runs at the center frequency plus the offset.