On 20 Jul 2002 Terry Fritz told the Tesla list he had been studying off-line Tesla coils, coils with no high-voltage transformer that run straight off the mains. So far it was purely a computer model, conventional in every part except an IGBT as a solid-state spark gap and some rather odd MMC capacitors. The 240 V split supply, rectified by two diodes, charges 50 µF of primary capacitance to about 679 V at 60 bps. The primary is a single turn of 1 inch copper pipe and the resonance is 16 kHz. The IGBT takes a spike of over 2000 A sixty times a second and is quenched electronically at the first notch to trap the energy in the secondary. Draw is about 4 A RMS from the wall, around 700 W. In 2004 he added that the idea dated from about 19 Jul 2002 and that Steve Conner had taken it far further, meaning Conner's Mini OLTC of 2003 on this tree. The schematic he linked, on hot-streamer.com, was never archived. His other work, spark-load modelling and ScanTesla, is on the wall below the trees.
Sources
- pupman.com: Terry Fritz, Off-Line Tesla coils (OLTC), 20 Jul 2002
- pupman.com: Terry Fritz, the reply (10 Jun 2004)
This is the card from the driver tree, written from what the builder published. Send corrections through the forum.