SGTC doesn't work with homemade transformer
uzzors2k, Sat Feb 24 2007, 08:15PMI tried putting a homemade HV transformer into my mini SGTC, but with no success. First - do SGTCs require DC or AC to work, or does it just depend on the frequency? If I need to rectify the output should I use full or half wave rectification?
The mini HV transformer is made from an ATX core, gives good arcs and strikes from about 7kV. The gap in the Tesla coil is set for about 1-2kV. I'm running the transformer just like I ran an original flyback which worked in the SGTC, - flyback mode at about 30-40kHz.
Re: SGTC doesn't work with homemade transformer
..., Sat Feb 24 2007, 08:40PM
You need to rectify the output. I would use fullwave refcitication, using strings of 15 uf4007 diodes.
..., Sat Feb 24 2007, 08:40PM
You need to rectify the output. I would use fullwave refcitication, using strings of 15 uf4007 diodes.
Re: SGTC doesn't work with homemade transformer
Sulaiman, Sun Feb 25 2007, 12:10AM
Most SGTCs work on a sinusoidal ac charging voltage - 50/60 Hz line.
(NST, OBIT, MOT-stack, pole-pig etc.)
Usually each half-cycle charges the primary capacitor
which is then discharged by the spark gap and primary inductor
BEFORE the next half-cycle begins.
Sometimes there are multiple charge/discharge cycles within one half-cycle of the mains.
Anyway, this is why the common spark-rate is 100 or 120 sparks/arcs per second.
Your ATX-transformer flyback is like the 'Induction Coil' SGTCs of earlier days,
a few choices;
1)
A rectifier directly connected to the primary capacitor for about 7 kV charging voltage
2)
A rectifier into a relatively large 'reservoir' capacitor,
then 'resonant-charging' (inductor + Diode) for about 14 kV charging voltage.
3)
A Cockroft-Walton (Greinacher) voltage multiplier for 7 or 14 kV charging voltage.
(one or two stages)
Since you are operating the ATX transformer in flyback mode (in my opinion the best/simplest choice)
all you need is (as above) a single high voltage rectifier!
Sulaiman, Sun Feb 25 2007, 12:10AM
Most SGTCs work on a sinusoidal ac charging voltage - 50/60 Hz line.
(NST, OBIT, MOT-stack, pole-pig etc.)
Usually each half-cycle charges the primary capacitor
which is then discharged by the spark gap and primary inductor
BEFORE the next half-cycle begins.
Sometimes there are multiple charge/discharge cycles within one half-cycle of the mains.
Anyway, this is why the common spark-rate is 100 or 120 sparks/arcs per second.
Your ATX-transformer flyback is like the 'Induction Coil' SGTCs of earlier days,
a few choices;
1)
A rectifier directly connected to the primary capacitor for about 7 kV charging voltage
2)
A rectifier into a relatively large 'reservoir' capacitor,
then 'resonant-charging' (inductor + Diode) for about 14 kV charging voltage.
3)
A Cockroft-Walton (Greinacher) voltage multiplier for 7 or 14 kV charging voltage.
(one or two stages)
Since you are operating the ATX transformer in flyback mode (in my opinion the best/simplest choice)
all you need is (as above) a single high voltage rectifier!
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