Kapanadze Cousin - DALLY FREE ENERGY

[NickZ]

 This TL494 based driver board is cheap, but would it work for the induction circuit? It goes to about 31.5khz, default frequency, to 300khz, or so.
It probably is too low frequency for the Kacher circuit? Or not?

  http://www.ebay.com/itm/TL494-KA7500-DC-9V-25V-Driver-Board-DC-DC-Converter-Inverter-Boost-Module-PWM/181449170972?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D29981%26meid%3D30dc72264dca4a97a16b1bc6190c0221%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D141408846492

[Dog-One]

I just decided to made everything much easier with the Arduino and the DDS9850 signal generator.  It offers me two output of sine wave and two SQR waves up to 40MHz. Together with the Arduino's logic I do not see any problem. Especially synchronization will be much easier.

Smart move.  A microcontroller can easily generate the burst frequency, the burst itself and divide down by 100 to drive the toroid transformer.  All you need to add is the current sense transformer to ensure the burst begins at the correct location on the current sine wave of the induction heater coil.

[Dog-One]

  Remember that Ruslan says that a mosfet can mess up the Kacher signal, so not to use it.

So I don't.  The Kacher that is.  Driven with a tuned signal, the MOSFET performs admirably.  The trick I'm seeking is matching this drive to an appropriate primary winding.  Changes such as wire thickness that you wouldn't think would even be noticeable, completely alter the characteristic waveform.  I can see where Tesla would refer to this process as more of an art than a science.

Anyway, another week or so and I should know whether I have met all the conditions necessary for this device to function as Ruslan's does.

[John.K1]

Hi Dog.

Thanks for advice. I am going to order some current sense transformer. There is many types on the market. What should I be looking for?

[Dog-One]

Thanks for advice. I am going to order some current sense transformer. There is many types on the market. What should I be looking for?

This one works great for me.  Just connect a shunt resistor and you can get accurate measurements as well as a nice waveform to tune with.

If you can't get this exact one, look for something with the proper bandwidth and current capability.  Many of them out there are rated for line wiring work and may not function properly in the KHz range.  This particular one does because it was designed for switching power systems which typically run at 100KHz.