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