Microprocesor Based VIC/PWM Controller

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Geoytex, I have one suggestion if you build such a nice PWM micro controlled.

We are not seeing any positive side pulsing.
Will this work on the positive line?
Work that into the outputs.
I know you don't care for the positive side, but thats more control. More variables!

You can do it.
 

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Mr. Dankie,

I think you may be suffering from unjustified paranoia.    Take a deep breath and relax.

As I said in another post,  I will only consider building something like this  to sell if there is enough interest.
I am building the prototype for my own use in research and experimentation.   If it works out that someone wants and can
afford a system like this,  then I will consider building a few more.     Otherwise I will keep it to myself and  possibly share
the design  in the  Public Domain.  

If I truly wanted to compete with you I would  design a simple manual  dual output PWM board around a  79 cent 8 bit microprocessor,
program it to do whatever yours does (and more),  have it assembled in China,   and  then and sell it for $79 (and actually make money) . But that is not what I am after.   I have little interest in the money.  

But be assured that I am not going to stop what I am doing because you are afraid it my cost you some sales.  What I am doing is not
going to hurt your sales.  

So relax .  You have  nothing to be afraid of  here.  

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Geoytex, I have one suggestion if you build such a nice PWM micro controlled.

We are not seeing any positive side pulsing.
Will this work on the positive line?
Work that into the outputs.
I know you don't care for the positive side, but thats more control. More variables!

You can do it.

Did Meyer pulse the positive side?  I don't  think so.    I went over the WO patent  schematic in detail and saw where the positive side voltage amplitude was controlled by a feedback circuit ,  but that was not actual  pulsing  of the positive side.  It was more like a voltage regulator that adjusted voltage based upon engine demand  and/or gas pressure.
 
Now if there is evidence based  upon someones research and experimentation  that positive side pulsing is beneficial,  I would certainly be interested in seeing  that data.   Certainly the positive side "could" be pulsed ... kind of like a synchronous buck cell.  Not a problem for a micro based system.  The timing would just have to be correct.

Edit:  Let me clarify a bit.  I recently had a discussion with a nice gentleman working on this stuff and he was of the opinion that the circuit in the WO patent was pulsing both the high and low sides simultaneously.  I went over the circuit with him component by component to show that it was not.  Only the low side was actually switched.    This is what I initially thought you were referring to... simultaneous switching of both sides.    I see that it is not what you meant .   

 

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Positive side pulsing.
Fig 8B patent 5149407 shows pulsing positive in 2 places.

FIG6 patent 4798661

Many other examples are available.

I think your basing your data on old Meyer patents.
Newer stuff shows positive pulsing.

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Did Meyer pulse the positive side?  I don't  think so.    I went over the WO patent  schematic in detail and saw where the positive side voltage amplitude was controlled by a feedback circuit ,  but that was not actual  pulsing  of the positive side.  It was more like a voltage regulator that adjusted voltage based upon engine demand  and/or gas pressure.
 
Now if there is evidence based  upon someones research and experimentation  that positive side pulsing is beneficial,  I would certainly be interested in seeing  that data.   Certainly the positive side "could" be pulsed ... kind of like a synchronous buck cell.  Not a problem for a micro based system.  The timing would just have to be correct.

from what i understand is stan was controlling a analog signal on the positive side.. it allowed analog pulse to be produced on the  duty cycle gate and he had a digital signal on negative side of the transformer.. it has the matching duty as the analog but is a digital signal variable from 0-20khz.. these are my understanding from reading his notes on the cell driver circuit and the variable amplitude ... them two, the analog and digital working across the transformer in sync create signal 49axxx49n.. to my best of understanding..  i think you would use the duty cycle gate to send to gass processor and valve gatting as well, and have the logic needed to put them in sync by whatever means..  i also beleive stan had one of his choke electricaly linked to the negative side by the digital gate.. i think thats how he could transfer a clean signal into the cell. by gating it to ground and it would super impose onto primary? just throwing that out there.. i think positive choke is just linked to copper secondary through the diode.

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Positive side pulsing.

Fig 8B patent 5149407 shows pulsing positive in 2 places.

Figure 8B of  5149407 shows a bipolar transistor used as a  "high side switch".    Both switches are high side switches in this
drawing.  Same thing in 4798661.   Meyer uses low side switching other circuits.   I could be wrong,  but I'm not  not sure that the load cares too much  as to which side is switched.   Each causes current  to flow when closed and current to stop when open.  Spice models show no difference in the  final waveforms using either technique.   However there may be some advantages in using a high side switch.  But that is probably something for discussion in another thread. 

In any case,   the PWM  output  of a microprocessor  based system can turn on or off a high side bipolar transistor  just as well as it can  a low side FET. 
 

  I think your basing your data on old Meyer patents.
Newer stuff shows positive pulsing.

The patents you referred to were applied for in  1985 and 1989 and show high side switching for their respective  applications.  These were block diagrams and not actual circuits

WO9207861 applied for  1990 (Later)   shows  low side switching  in figure  5  for a particular application.  In this patent  the low side switch is shown in a more detailed ans specific circuit.   Yet in Figure 10 of the same patent he shows a boiler plate VIC using a high side switching.

My take is that the date of the patent is irrelevant. Newer does not necessarily mean better.   The boiler plate VIC drawings are  meant to show  that the coil is pulsed and not necessarily that it must be with a high side switch.   Again,  I  don't think the transformer primary cares with side the switch is on.  It only cares when and how often the current is allowed to flow.   
 
Goey

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@Goeytex

I need a simple solution to regulate the amplitude of the pulsed/gated signal that has to be controlled with a micro processor.
More external hardware is necessary I think. I can only regulate the amplitude with the FET driver (external power supply +- 15volts ) Input PWM signal of the driver is 3.3 volts.
(I want output to be regulated, that my FET can work as a pulsing resistor)

I have tested my setup with two PWM signals that i can regulate with a windows dot.NET application. Micro processor is connected via USB.


br
Webmug

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Positive side pulsing.

  Again,  I  don't think the transformer primary cares with side the switch is on.  It only cares when and how often the current is allowed to flow.   
 
Goey

I agree with Goey

A coil generates the exact same signal regarless if pulsed using negative or positive switching. Now using both can be an option for gating... but since we can do that using one single switching circuit, I don't see the need for it.

by the way, the PCB for the satble gated 3 channel PWM does have a section to add the positive switching by adding a power PNP or P-Channel FET.