Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Mads Barnkob, Mon Oct 10 2016, 07:00AM

Looks good, will you share the test setup and more details about the hardware used to create these sparks?

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Newton Brawn, Mon Oct 31 2016, 12:52AM

so,

what is the electrical arrangement ??

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Tue Nov 01 2016, 04:07PM

Here are pictures of the commercial device used to generate the sparks of the induction coil shown above:







Pictures of the used mid-size induction coil as well as the dimensions of the coil will follow.

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Thu Nov 03 2016, 03:37PM

This is the hardware used for generating the sparks above:



The dimensions of the coil are:
length 50 cm
diameter 18 cm

Measurements of the primary and secondary voltages will follow.

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Mads Barnkob, Thu Nov 03 2016, 06:45PM

Seems like it is a multiply tapped transformer for different voltages that charges a capacitor which then avalanches the SCR and the SCR dishcarges the capacitor into the primary coil?

It does not seem there is any kind of control circuitry, unless that black block is something.

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Thu Nov 03 2016, 08:01PM

Hi Mads Barnkob

I agree completely with your assumption.
It is a very simple circuit.
I hope I can find the circuit diagram within a few days.
At the moment I try to measure the output voltage of the interrupter.
First with an ohmic load then with the primary coil as the load.

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Mon Nov 07 2016, 02:24PM

In the following figures, the voltages of the pulses (pulse rate is 50Hz) of the thyristor device are shown at an ohmic load of 0.5 ohm as a function of the switch positions 1 and 5.

0.5 Ohm is the resistance of the primary coil of this mid-size induction coil shown in the pictures above.

Y axis 100V/cm, measured with a Tek P6013A
X axis 200us/cm

Note the high voltages (e.g., -300V and + 100V) of the pulses and also the high currents with the ohmic load:
-600A and + 200A in switch position 5.





Measurements of the pulse voltages of the thyristor interrupter with the induction coil as a load will follow.

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Tue Nov 08 2016, 01:31PM

In the next two pictures, the voltages of the pulses (50 / second) of the thyristor device at the primary coil of the induction coil are shown as a function of the switch positions 1 and 5.
The primary coil of the induction coil used has 0.5 Ohm.
On the next two pictures, the tip and the plate of the induction coil are more than 20 cm apart and there are no direct sparks between them.

Y axis 100V / cm (measured with a Tek 6013A)
X axis 200us / cm






This reproducible structure of this positive wave is amazing, at the moment I have no explanation.

In the next two pictures the primary voltage is shown at the switch position 5, the plate is about 150 mm away from the tip of the induction coil and sparkovers take place:




These secondary sparkovers are also visible in the primary voltage profile.
The amplitude of this positive half-wave is smaller, the width of this half-wave is smaller and this half wave is strongly structured.
I will repeat these experiments at smaller distances from tip to plate to ensure that each
pulse of the thyristor device also results in a discharge, which has not been the case for the last two pictures.

Measurements of the secondary voltages of the induction coil will follow.

Please, let me know your comments.

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
paris, Fri Nov 11 2016, 05:16AM



the black box looks like its a relay

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Fri Nov 11 2016, 04:23PM

I hope these two pictures give more information.

I think there is no relay.

The "black box" cools only the rectifier diode.

The big resistor has 420 Ohm, the big capacitor has 4 uF/600V

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
paris, Fri Nov 11 2016, 06:48PM

now I can see its a heat sink . what is the brand name of the power supply?

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Fri Nov 11 2016, 07:49PM

The brand name is NEVA:

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Newton Brawn, Sat Dec 10 2016, 07:37AM

Is a Tesla coil driving another Tesla ?

Re: Discharges of a thyristor controlled induction coil, spark length is about 150mm
Physikfan, Sat Dec 10 2016, 03:38PM

No

As you can see in my post of November 7, this thyristor commercial device delivers a small double pulse ( +100V and -300V) at a pure ohmic resistor of 0.5 Ohm in position 5.
In my post of November 8, this thyristor commercial device delivers a much broader double pulse ( +200V and -400V with a special structure) at a real primary coil (0.5 Ohm) of this mid size induction coil (my post of November 7).