Re: Towards the autonomous lifter - electrostatic voltage generators.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Bob,

At 08:09 PM 7/1/2005, you wrote:
> .....................
>
> I wanted to save weight by eliminating the
> transformer. But it may turn out the large number of
> components for a kilovolt CW multiplier without
> transformer would cancel out the weight savings. I
> discussed this in a post to www.powerlabs.org copied
> below. A question I would like to see answered is what
> is the weight for a microfarad capacitor?
> The post refers to the 555 oscillator IC. I needed
> that because the CW requires AC while the lithium
> batteries put out DC. The 555 provides a simple
> lightweight method for converting DC to AC:
>
> DC to AC Inverter with the 555.
> http://www.uoguelph.ca/~antoon/circ/555dcac.html
>
>
>   Bob Clark
.................

I ran about 1 million models through ScanTesla to see what it would come up 
with for a Tesla coil powered lifter.  I assumed a 40V input and a DRSSTC 
drive system.  It was driving 50M ohms or 50kV at 1mA @ 50W.

ScanTesla  V-7.40  July 1, 2005  Terry Fritz
Cprimary = 1.000000e-008
Lprimary = 2.105100e-004
Rprimary = 1.500000e-001
Coupling = 0.350000
Csecondary = 0.200000e-010
Lsecondary = 9.000000e-002
Rsecondary = 3.910000e+002
Cload = 1.000000e-007
Rload = 5.000000e+007
BPS = 1000.000000
Dwell (T1) Time = 5.000000e-004
Ilprimay Maximum = 24.595672
ICprimary RMS = 8.769052
VCprimary Maximum = 3883.999639
VCsecondary Maximum = -73522.366980
Coil Power = 64.282184   Primary Bang Energy = 0.064282
Load Power = 13.118890   Load Bang Energy = 0.013119
Primary F0 = 109694.225469   Secondary F0 = 118627.090570

It actually does not look too bad but the pulse output graph shows a new 
complication:

http://hot-streamer.com/temp/LifterPower-01.gif

Basically, it would need to be "voltage regulated".  You would need a 
pretty good coil but you could not run it full power or the voltage would 
go far too high.  If you made it for a lower voltage, it would have no 
efficiency...  So you would need to have a feed back path for the output 
voltage and modulate the DRSSTC circuit to maintain say 50kV on the 
output.  So we have:

1.  Vacuum impregnated epoxy "Tesla coil" to get high voltage in a small 
light size.
2.  DRSSTC drive from say a standard little H-bridge DC motor driver.
3.  Primary current feedback.
4.  Output voltage feedback and regulation.

A 10nF 4000V RF cap is something American Technical Ceramics could come up 
with.

The RMS current though the driver "might" be a problem!!  Most small drive 
ICs would need external FETs to drive that kind of RMS current.  But the 
current should go down in a more steady state situation.

It is probably "possible" to make a little Tesla coil air core HV power 
supply like this.  But it is not at all straight forward to do.  Probably 
be some "bleeding edge" problems to be worked out...

I wonder if the epoxy coil would end up weighing just as much as a small 
standard ferrite...

Use aluminum magnet wire to save weight on lower current stuff.  DigiKey 
also has 0.032 inch double sided PCB material which is far lighter there too...

I trust you have looked into those 12v mini inverters for lasers like 
Meredith Instruments sells too:

http://www.mi-lasers.com/cgi-bin/shopper.cgi?search=action&keywords=power_supply

They look heavy, but you might be able to get the bare guts before they are 
impregnated with plastic and have the voltage changed if you were real nice 
to whoever makes them OEM...  That would save a ton of work!

Cheers,

        Terry