Simple Blocking Oscillator Circuit

[Farrah Day]

Hi guys, I was wondering if anyone can explain what is actually happening in this circuit? That is how are these effects being created?

You will see from the following video by Slayer, quite spectacular results from this extremely simple cct. I'm struggling to understand how the actual circuit even works, let alone the nature of the extremely high voltages achieved.

http://www.youtube.com/watch?v=naN-cLCgDyY

I'm currently experimenting with these blocking oscillators with views to implementing something similar on my Closed-Loop Electrolyser, so any help in understanding the principles of operation involved here would be much appreciated.

[Farrah Day]

Thanks for that EM, your explanation makes good sense.

Such a simple circuit, but such impressive results.

Incidentally the cct operates without the 2 diode and LED on between the base and -ve, he put these in to simply indicate the cct is on and working.

[BEP]

The circuit this guy is using is definitely not a blocking oscillator, as those use magnetic cores and saturation to switch,

I see your point about wave shape coming from core hysteresis. Never thought of it that way before... go figure

All this time I've been throwing together oscillators and calling them blocking oscillators. You see, I thought the main feature was synchronizing with ambient signals. I realized this can happen with almost any LC oscillator, even more so with air cores.

Farrah Day,

Do you plan to 'up-size' it for more power? It may help to place the planar primary in the middle of the tube length.

[Farrah Day]

That's it EM, it's just a mini Tesla!

What I intend to do is get such a circuit and tune it to a frequency induces the greatest ionisation of a particular body of water. From there I will use it in my Closed-Loop Electrolyser.

I have first to determine the best frequency to induce ionisation of water and then build a coil configuration to match this frequency. All good fun!

[Rosphere]

Here's my mini-Tesla coil from long ago revamped to use an Armstrong oscillator topology.
Just threw this together this afternoon, frequency still about the same as before  (few MHz)

I have always liked your "mini-builds," EM, and this is no exception.

Thank you for sharing.

[Farrah Day]

EM, what is the green colour looking wire in your photo, where is it attached in the cct and what is it's purpose?

Thanks

[Farrah Day]

Yep, that would be the one, it looked to have a green tinge... tho' maybe it's my monitor eyes playing up!

Thanks.