Successful TPU-ECD replication !

[MeggerMan]

Hi Chrisc,
You may want to look at the TL494, it has duty cycle control (45% to 0%) and the output I think is about 200mA so you can drive the mosfet directly.
http://focus.ti.com/lit/ds/symlink/tl494.pdf
Some of the newer PWM controllers have a true drive(push-pull) output and are even better.
I have had the TL494 running up to 700KHz.
Or you can build a DDS 20 kit from ELV in Germany, cost about 60 euros plus you need an AD811 op amp if you want the sine wave output.
http://shop.elv.de/output/controller.aspx?cid=74&detail=10&detail2=6325
The duty can be controlled by an external op amp connected to the sine wave output.
The good thing with the DDS 20 is it has a good clear display of the freqency and has a sweep mode too.
But for simple, cheap and chearful, the TL494 would be a good bet.

Hi Wavewatcher,
Some useful info you have there. Can you find out the number of  turns we need to get resonance at 35KHz?
I have some LMR400 cable that I could use for the mobius loop.
What about using microbore pipe, say 8mm or 10mm?
Easy to bend to shape.

Hi All,
I did the first experiment that Otto/Roberto has shown in their PDF report.
I could not see any peaks with different lengths of solder wire.
The pk-pk increased as the wire got shorter.
Going from:
100cm of 1.2mm solder wire, 5V input at 1.9 amp pulsed at 7.6KHz (best amplitude) pk-pk of 27V
down to
5cm, 5V, 1.96amp, 7.6KHz, pk-pk 34V.
Coil was 50 turns of 0.56mm enameled copper wire.

It showed a linear increase for the shorter wire.

It made no difference if the wire was inside the coil or not. 
I must be doing something wrong.

Rob

[z_p_e]

Thanks Rob for the TL494 info, and the heads-up on the DDS board.

I've emailed ELV to see if they have an English version of the info pdf and if they'd ship to Canada. This one looks very promising.

Darren

[Hoppy]

The SG3525 is a another PWM chip. This one has totem-pole output and an anboard regulated 5V supply. I've used these in several applications and I prefer them to the TL494.

Datasheet at: -
http://www.chipcatalog.com/Datasheet/372D30FBF5AC679BCC1E8BCA3B07EC4C.htm

[giantkiller]

Thanks Rob for the TL494 info, and the heads-up on the DDS board.

I've emailed ELV to see if they have an English version of the info pdf and if they'd ship to Canada. This one looks very promising.

Darren

Yeh, this is definately a hook. I'd buy 3 right off the bat simply to get 20mhz @ below 150USD ea. for small form factor and portabililty. The output would be to spec and very tight. Very professional.

--giantkiller.

[giantleap]

I think this is a good time to remind people of something SM said.

"I ask you, what are these guys thinking about when they let their
ego's force them to ignore things i have said in the beginning and go off
trying to design and develop their own control devices using SS units.
SS units which are OUTBOARD of the collector ring i might add?
Some of them have gotten results and some of them have gotten big
power surges and dissipation of heat... all of which is wonderful and
certainly proves the point that there is truly something going on here.
BUT, i guarantee you that their SS control devices are all sitting right
beside the collector... aren't they?
They will probably never start the coil and get to catalyst.
I am not saying it is impossible, but it will Damn difficult for these guys to
get more then a big bang once in a while.
And just like me, that big bang will excite them enough to continue for a
while longer.
Maybe one of them will read back and see where I said the SS control
device must be placed inside the collector coil.
then they will explode with, MY GOD, maybe that is the reason why......
and off they will go. in the right direction at least.

God Bless
Tim.