always improving...
Ya know the problem with T- Coiling is that you never seem to have enuf power... so what do we do???
We improve, increase, modify, and make it bigger :)
My first power supply consisted of a 10 Amp Variac and a couple of 15KV 30mA nst's. Then I did the unmentionable... I went directly into a Pig system. But that wasn't enuf, I eventually went with a seriesed set of 2 14KV units out-putting 32KV with 2 1256D variacs....
Hold on now.. I went even bigger. Seeing the need to supply the BIGPIG with even more food, I rebuilt the primary power supply. But I also like to play with lasers ... so this required a need to design and implement a DC source... 300+ V at at least 80A .
So off I went to Ebay and spent a fortune ( shhhh dont let the wifey find out ;) ).
2 more 1256D's, Hi power resistors, mucho mongo Diodes for a full wave bridge, and enuf capacitors to filter even the most demanding
25 Watt laser. Emergency shut down button, volt meters, amp meters, some really nice 60A filters, hi power switches and relays, and 6 miles of wire along with a DC motor to adjust the variacs. And finally, a case to put it into....
To start... I paralleled/seriesed the 4 1256D variacs ... I had to make 2 paralleling chokes to do this feat... I used the cores from 2 7.5 amp variacs along with some # 4 THHN copper wire. This feeds into a main switch which will send the voltage to either the Tesla coil secondary power supply ( the seriesed piggie and inductor) or to the full wave bridge and filter cap assembly. Since the Cap system is huge ( 72 caps at 450 VDC at on average of 5000 uF per cap.... .36 FARADS!!!) I needed to have a resistive temporary feed to the DC side ( imagine the load all the caps would have at turn on.... ouch) so I made a timer circuit which controlled the initial start ( 30 seconds to allow the inital ramp up of the cap feed thru some power resistors). Once the timer kicked out, the feed was direct to the caps.
To control the DC side amperage I needed some type of controlling factor... I used a linear pass bank made from 2 I-90 laser supplies ( 40 transitors rated for 350V 10A each). Eventually I am going to get the IGBT's ( 1200V @ 200A each.... 4 of them for a total of 1200V @ 800A) working and replace the LPB.
Since the linear pass banks were water cooled to start with I needed to introduce a cooling system into the power supply. Ebay does it for me once again... a radiator from an old laser and a pump from a dye laser fit the bill...
The final specs at the moment are AC side 280 VAC approximately 80A. DC side 380V approx. 55A. Water cooled linear pass bank, emergency shut down, output power supply is either AC or DC.
Here are some pictures of the monster power supply....
Front Panel of the new supply
from left to right
main power switch, variac direction switch, full ACV and above ACV for each leg,
the black switch bottom left is for either pulse or constant AC, yellow is the pulse, red is the hi volt pulse for laser,
2 black switches control filament power and magnet power for laser,
large black switch in the center changes power from AC to DC components, DCV meter, DCA meters.
This is the 4 1256 D variacs along with the paralelling chokes and the pump that will be used to cool the LPB.
here are the filters used to "try" to keep backfeed out of the house wiring, they are rated for 60A 250VAC,
I paralleled the ins/outs to spread out the current a bit, seems like all it really will do is give me 3 chances ;) each leg to blow them up.
Top View of the power supply case,
the Linear Pass Bank, filament transformer, filter caps for the magnet supply, main switching assembly.
This is the DC side of the cabinet, the full wave Bridge Rectifier, the trannie for the magnet coil, switches( relays), and some of the caps for the filter.
a wide shot of the DC side
the misc trannies for the laser, FWBR, and 72 caps
power resistors for cap charging during the inital turn on and a smaller power resistor to drain caps
when the power is removed from the DC side..
more to come later....