Dave Lawton circuit

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Post of Sebosfato:

this is the last circuit i have worked on it has many possibilities... <br /><br />the frequency mixer can be used with other circuits if you want <br /><br />the A connector is from gas management system and should be held at a logic level to set the pll to run while we don&#039;t have the gas pressure signal the gms system shuts the pll down when the pressure is reached simply that!<br /><br />the accelerator control mess around with the voltage going to the primary coil to detune the circuit to control the rate of gas production during on demand operation.&nbsp; <br /><br />the gate frequency generator is perfect from 0 to 100 percent at whatever frequency you just need many rotary switches for the number of capacitors the potentiometer gives an octave <br /><br />and all the rest work...&nbsp; the feedback coil should be as big as the primary but could be smaller depending where you put it... if it is as same as primary with a capacitor connected in parallel it locks automatically.... if it indicates a lock in automatic mode and goes to the max or min frequency in the manual range than you don&#039;t have resonance happening or if its going to min the polarity of the feedback coil is wrong! <br /><br />don&#039;t forget to look all the pins of all ics some are missing,...<br /><br />If it don&#039;t work you missed something<br /><br /><br />Good luck

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Thanks a lot Steve!! I know about the pin 12 should be connected to the pin11, right? As i´m not electronics expert and i´m not family with these chips, could you tell me where i have to add the rotary switch with the capacitors and values for caps for 40- 46Khz range? at the 555 like Lawton circuit? Maybe working together a better future its possible.
Thanks again!!

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Hi to you all,

I want to use my gas splitter dry cell (using the H2 only for my car) by using a circuit which work with frequencies to avoid the big current consuming. So I stumbled on the Dave Lawton circuit and build it on this PCB (http://i1285.photobucket.com/albums/a600/knovos2/IMG00480-20130224-1419_zps826b8dd1.jpg)
In spite of all the effort I did not get the high voltage spikes (1200 volt?) according to the attached PDF-file cramton-lawton.pdf. Both sections of the circuit work fine but the output is nothing more then spikes from 8 to 9 volt at 0.5 amp. To adjust the 4 pots to get something done is a kind of gambling process I don't like it at all. Further investigation bring me to a guy named Ravi who added some big changes to the Cramton circuit which tells me the Cramton circuit is a good basic design but needs a lot more (see attached pdf-file Ravi Cell). His modifications seems to work very well but take a lot of time and money. It kicked me back in my chair, no I don't want to do all that. Back on the web I discovered a different circuit from Dave Lawton which does the same Stan had, a self tuning resonance circuit. Look at page 10-61 from the attached pdf files chapter10.pdf My question to you all, is it worth trying to build this circuit (http://www.leonknook.com/circuits/Lawton%20self%20tuning%20circuit.jpg)
and is there a PCB available (open source). Are there alternatives who are better or give good results?
Kind regards, Knovos.

Here is the PCB for the PLL Cramton-Dave circuit. http://www.courtiestown.co.uk/index.php/electrolysers/dave-lawton/dave-lawton-pll-full-kit.html

but it only works between 40Hz 18Khz, anybody could help to modidy it to achieve 46Khz? please any idea or info about who could help its very welcome.

Hi Zafiraboss,

Welcome to our forum here.
You made a nice PCB!
Thanks for sharing.

To get the oscillator a little bit higher to 50khz is not a problem.
However, its a question if the pll will take it...

Steve

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Thanks Steve but i just found it. Thats why i want to modify it. Let´s find the way to do it and the PLL catch it at higher frequencies. Spread the question with proffesionals on electronics please!

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here is the circuit

this is the last circuit i have worked on it has many possibilities...

the frequency mixer can be used with other circuits if you want

the A connector is from gas management system and should be held at a logic level to set the pll to run while we dont have the gas pressure signal the gms system shuts the pll down when the pressure is reached simply that!

the accelerator control mess around with the voltage going to the primary coil to detune the circuit to control the rate of gas production during on demand operation.

the gate frequency generator is perfect from 0 to 100 percent at whatever frequency you just need many rotary switches for the number of capacitors the potentiometer gives an octave

and all the rest work... the feedback coil should be as big as the primary but could be smaller depending where you put it... if it is as same as primary with a capacitor connected in parallel it locks automatically.... if it indicates a lock in automatic mode and goes to the max or min frequency in the manual range than you dont have resonance happening or if its going to min the polarity of the feedback coil is wrong!

don't forget to look all the pins of all ics some pins are not show,...

If it dont work you missed something


Good luck

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Thanks a lot!! there is anybody selling this circuit in PCB? or ready mounted? i could try but... will be a disaster lol

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There is a pen that you can use to draw directly on the board and than you simply drop the board into an acid that corrode the copper that is not coated with the pen.

My best tip i can give to you is to not perforate the boards... make the traces over the board on the same side of the ics this way you don't need to make the holes and there is less confusion..

Another good idea is to use double layer boards so this way you don't need many wires to jump...

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Well i will have to face it.  Thanks! God bless you!