Kapanadze Cousin - DALLY FREE ENERGY

[Pinoy_Tech]

   Hoppy I'll test the driver output and maybe post a video of that stage of the circuit.
The 15v filtered supply lines are already connected to the drivers. Not using the bipass caps, for now as I don't have them. Nor does Stalker use them on his fet driver set up.

   Magpwr: what type of cap would you recommend? Ceremic, such as ceramic disk type? Such as the ceramic 102 cap shown on Pinoy's driver.

   Pinoy_tech:  Thanks for sharing,
   I've downloaded all of the attachments. At least the pictures I could open. Not the others.
           NickZ

Via pc, you can open that through pdf viewer. I am using adobe acrobat 11.


pcb tnr mthd means for ironing pcb method, cttng method is a mirror view,
topsilk is an optional top guide to speedup the [size=78%]component placement during assembly. [/size]
 

[NickZ]

   Pinoy:
   OK, I managed to open the PDF files.
   The main schematic is similar to the one that I posted, but is not just the same.
   Do you know of anyone actually building this device? Have you built this up yet?

[AlienGrey]

   Pinoy:
   OK, I managed to open the PDF files.
   The main schematic is similar to the one that I posted, but is not just the same.
   Do you know of anyone actually building this device? Have you built this up yet?

it's changed i get a download arrow now !
thanks

[NickZ]

   Hoppy
   Here's a pic of my TL494, with the mosfet drivers installed.
I received the tiny drivers instead of the regular sized ones. So it was alot more work. I'll be sure to get the right ones, next time. Along with their sockets on both the TL chip as well as the driver chips sockets.
I'm going ahead with it anyway. Here it is so far.
I'll connect it up to the scope tomorrow.

[TinselKoala]

The TL494 is very popular with solid-state Tesla coil builders. It can be "overclocked" to way beyond its specified maximum frequency (if you use genuine Texas Instruments manufactured version.) I've built an excellent TL494-based SSTC myself, with a high-power mosfet H-bridge to drive the primary of the TC proper. I didn't use driver chips though, I built drivers out of discrete transistor totem-pole and h-bridge current amplifiers, finally driving trifilar toroidal gate drive transformers for the high-power H-bridge feeding the primary. At the frequency I was using, the TL494 didn't produce a nice symmetrical signal from its two outputs so I made an inverter stage from 2n7000 mosfets that produced symmetrical push-pull from just one of the 494's outputs. Worked great. If you look for TL494 SSTC circuits you will find versions that are identical to that part of the Kap schematics you are working with.

Nick, there is a voltage-divider chain of (probably) carbon resistors in the Focus circuit of your scope. It is very common for these resistors to drift in value or even go open circuit. It is an easy fix if this is the problem, easier than changing the focus pot. You may even be able to identify the bad resistor just by close visual inspection. Be careful as this is part of the HV circuitry in your scope.

Congratulations on soldering those tiny surface-mount driver chips. I've made the same mistake, ordering SM parts instead of thru-hole, and it's a pain. Yes, definitely plan on using sockets and TH components for your next build version. Keep up the good work!

For mounting your mosfets you may like to consider using the "blue" 3-pin connectors like this:
http://rarecomponents.com/store/image/cache/data/1618-500x500.jpg
They are a perfect fit (5mm pitch) for TO-247 style mosfet pins.  I use them a lot and they are available from many vendors for cheap.