Coil Shorting Techniques.

[kEhYo77]

Hi Aaron5120
I am still building my proper setup for my way of doing things in coil shorting.
I am on a learning curve with each individual block/module and I test them in different setups to make things easy for troubleshooting.
At this moment I am testing the shorting coil module in a motor/generator setup
But I want to go solid state and short a coil of an air core transformer.
I'll post some scope shots soon...

kEhYo

[drak]

Hi Aaron5120
I am still building my proper setup for my way of doing things in coil shorting.
I am on a learning curve with each individual block/module and I test them in different setups to make things easy for troubleshooting.
At this moment I am testing the shorting coil module in a motor/generator setup
But I want to go solid state and short a coil of an air core transformer.
I'll post some scope shots soon...

kEhYo

How is your experiments going? I'm thinking of trying out some coil shorting myself. I started playing with solid state oscillations in a LC tank using a quad filer with some polypropylene caps. I use the inductive collapse of one of the coils at the correct time to swing the oscillation in the output. If you can use atmel avr micro controllers, you are more then welcome to the software I wrote. I wrote a windows gui to interface with the avr to time the pulses correctly, and built a board that has a few n-channel and p-channel switches and a few voltmeters. Not difficult to build, but you can build whatever type of switches you want as long as they run off of 5v logic.

Anyhow, just curious as to how it was going.

[pault]

observations

Some observations re. coil shorting in the hope of trying to understand the phenomenon:

Using the convention (r-charge) 3pm as a motor, with the generator coil mounted. I hooked up a simple ckt as shown in the attachments (coilshorting.png) and hooked up a scope. An analogue voltmeter (DC) was hooked up across the cap.

The scope has three traces. The top trace (flat line) is unused. The middle trace shows the waveform on the collector of the transistor. The bottom trace shows the waveform across the coil.

no-shorting.jpg is a scope shot with the machine running w/o the reed switch triggered. A nominal voltage of a few volts appears across the cap.

short.jpg is a scope shot with the machine running and the reed switch held manually near the rotor just after the gen coil - i.e. the reed is triggered (shorted) moments after the magnet leaves the gen coil.

With the reed switch in place, the cap sustains a voltage of approx 70VDC (ripple was not measured). The wheel appears to slow down a bit.

As can be seen in the scope shot, the reed shorts out most of the positive half-cycle of the A/C induced into the gen coil. The short ends when the negative half-cycle begins. A spike of some 70V appears when the short is stopped. Some ringing accompanies the spike.

The above test was done with only one of the 3 power coils hooked up. The core of the gen coil had to be pulled out about 2/3 of the way to keep the rotor from stalling. In a subsequent test, all three power coils were hooked up. The gen coil core was fully inserted, and voltages of around 190VDC were sustained on the cap (the cap is rated for only 200V, so the reed was backed off - it looks like I could have gone some 10's of volts over 200V).

Discussion / explanations welcome.

pt

correction: the rotor was actually turning in the opposite direction I described, hence, the reed switch was firing (shorting) just as the magnet was entering the coil, not as it was leaving. This is evidenced by the fact that the +ve (incoming) half of the induced A/C wave is shorted.

[boguslaw]

I think the solution might be simple yet complex because of compacting into one a few physical effects.

1. When coil is shorted it acts as RCL circuit on it's own small capacitance and inductance when inductance overweight capacitance. Effectively this causes ringing of high frequency

2. More important is the reflected wave behaviour. Think about it more, I will leave you here.....for while... (because I'm not following thread actively...)

I wish if Ismael Aviso would comment htat.....