(Modified) Dave Lawton PWM - Overview

Basic overview of the Dave Lawton Pulse Width Modulator while on Radio Shack Learning Lab breadboard. Covers "oscillator" circuit, "pulser" circuit, and (n-MOSFET) cell/VIC driver circuit.

My version of the Lawton PWM is modified such that the oscillator and pulser 555 timers have 6 capacitors each. This allows finer granularity and overlapping frequency selection while maintaining 50% duty cycle.

Other difference: n-MOSFET = (Motorola) MJE-13009 (400V, 12A)

Freq range: ~300 Hz - ~18 KHz
Duty cycle: ~99% - ~1%

Oscillator caps: .1uF, .22uF, .47uF, 1uF, 2.2uF, 4.7uF

Pulser caps: .01uF, .022uF, .047uF, .1uF, .22uF, .47uF

Otherwise, the circuit is identical to the "solid state" version of the Dave Lawton PWM.

Category:

Nonprofits & Activism

Tags:

• WFC
• electrolysis
• HHO
• generator
• Dave
• Lawton
• PWM

[evolution2015]

Hi,i would like to build this same circuit but i can`t find these capacitors, maybe you can help me. these are the capacitors i need.

100mf 16v electrolytic

47mf 16v electrolytic

10mf 16v electrolytic

1mf 16v electrolytic

220nf 0.22 mf ceramic or polyester

100nf 0.1 mf ceramic or polyester

10nf 0.01 mf ceramic or polyester

thank you

[usuryfree1776]

evolution2015,

i bought all the necessary components to build this circuit at my local Radio Shack. If yours does not have the components in stock, then either go to their web site & buy them on-line, or have the store place the order so you can pick it up there.

I would not be fixated on 16V either, you could use 35V caps w/o concern. also, look for radial as well as axial lead caps. this will sometimes help.

[earthhydro]

pulser circuit has different amplitudes? naw it takes a step generator to do that. meyers showed the stepped waveform after secondary of step up transformer was loaded with water cavity. not that meyers was really telling the truth on what he was doing but he showed us that much

[stevengates45]

Very impressive video, I have a question for you as I am trying to get a microprocessor to play musical notes. I have a formula for my PIC that can set a period and the same formula is used for pulse width. What I am stuck on is what ratio do I have the pulse width set at and what should I set my period to to have the correct duty cycle that will output the intended frequency? This is really troubling me. Any help is greatly appreciated.

[evolution2015]

Hi,usuryfree1776,

thank you for responding to my question.

i`ll try radio shack on line.

thanks again.

[turbulentflow187]

Great video and I like how well you explained things. I am having trouble with my Mosfet. It seems to put out a straight DC current (on the Oscope)with a pulsing gate signal being fed to it.

[nycresistance]

You are calling your zener diode a 220 ohm resistor at the end of your video, maybe you have your resistor where your diode should be and your diode where your resistor should be.