Proof of concept - perturbing a static magnetic field

[dutchy1966]

Hi Bob,

That sounds good to me. maybe you can post a schematic at some point.
I'm thinking about using a laptop to control switching through lines from the parallel port.
I'm just not sure if it will be fast enough....

Have you got any ideas on that?

Robert

[gyulasun]

....  I'm thinking about using a laptop to control switching through lines from the parallel port.  I'm just not sure if it will be fast enough....

Hi Robert,

You could use ready made power MOSFET driver ICs between your parallel port output and the MOSFETs gates, to make fast rise/fall times from the laptop's output.

Gyula

[bob.rennips]

....  I'm thinking about using a laptop to control switching through lines from the parallel port.  I'm just not sure if it will be fast enough....

Hi Robert,

You could use ready made power MOSFET driver ICs between your parallel port output and the MOSFETs gates, to make fast rise/fall times from the laptop's output.

Gyula

The IRF2117 are power mostfet drivers but require 10v for logic 1, so these wont work as I believe parallel ports work on 5v ? There are others that work on 3.3v+ for logic 1, so these would be ok. An ir2106 looks like a candidate for a closer look:

http://www.irf.com/product-info/datasheets/data/ir2106.pdf

But word of warning. I've had a well designed, commercial, stepper motor driver board with optoisolators, fuses etc complete fry-up, when messing around with TPU style coils.
I would almost guarantee that at some point your laptop will become a doorstop if you go this route!

This has also been mentioned on this board before. The Bob Boyce pwm3e circuit is very nicely designed and tested. I think he'll even sell you a pcb board. Buy the components and solder in! He even has step by step picture on how to do this!

http://www.oupower.com/index.php?dir=_Other_Peoples_Projects/Bob%20Boyce/Hydroxy%20Gas%20Projects/Control%20Electronics/PWM3E

[starcruiser]

Sorry Robert I was at work and .. well you know how it goes.

I am thinking of using a simple blocking oscillator for the signal source. I know this will not allow sync'ing the pulses but I am thinking this might do the trick, I may even try and use the generator coils as part of the circuit to really keep it simple (KISS is my motto). Besides using this Oscillator will allow me to keep the parts count down and I can use higher voltage transistors to allow for the higher voltages down the road.

I also have a few circuits laying around from my TPU experiments and was thinking about using them as well. I want to try a few easy experiments using what I have on hand and already built first then move it up to the next level as I go on.

I am with Bob on this, starting with 12vdc (batteries) and move on from there. This potentially keeps the output in check, but who knows, 12v maybe all we need?

[chrisC]

@all

See electricity through a magnetic field in video. Watch 4:57 and 5:07 into the video.

http://www.youtube.com/watch?v=ltnlviCqu70

chrisC