3v OU Flashlight

[magpwr]

I am speechless over here.
I do no know for sure what I have found, but my 3v flashlight V2.0 went crazy.

The power supply is at 2.59V, but I now have over 1 kV on the secondary! (540V in the picture)
It is, obviously, a resonance, but at this stage I am inclined to think it is a magnetostrictive resonance excited by an external (primary) magnetic field.

Anyway, at 230V ~ RMS it looks like I have enough power to light up a relatively big CFL light bulb while having the circuit self-sustain.

~A

hi avalon,

That signal amplitude looks very promising.
Are using the typical EPCOS core for experiment?
I had plans to scale up after a successful experiment.I have attached a ref MC34063 circuit which used for stepping up to 400volts.
Just use the external transistor and mosfet part and connect pin 1 to positive via resistor and pin 2 become output.
Not forgetting the diode needs to be changed to fast  response high voltage diode.

[d3x0r]

while shopping for cores...


stats of ferrite cores (including pot)
how to design/pick a core...

How to pick a core, need a target inductance, a target turns and/or current  (2 of the above)

They have cores with a A_L of 25,000 ; permability of 10000 at 10Khz; ...

Number of turns = 1000 * sqrt( L / A_L ) so for 53mH; / 25000  .... would be like 2 turns in a 30mmx19mm,  (13.3 center core)

; need a more specific target than 'round'

[verpies]

The coils that I am using do not have copper shields.

It's good to have a concrete reply.

I'm gonna guess the secondary was open circuit.

...but Avalon did not reply to that, so we have to guess.

Very high voltage rise is possible on this winding if it resonates with inter layer winding capacitance and the resonant frequency of the winding is hit.

My thoughts exactly.

But voltage alone is not power, there is no mention of a load.

Didn't Avalon report burning out some high power LEDs at high brightness?   You cannot light such LED's with voltage alone.

[Dave45]

hi avalon,

That signal amplitude looks very promising.
Are using the typical EPCOS core for experiment?
I had plans to scale up after a successful experiment.I have attached a ref MC34063 circuit which used for stepping up to 400volts.
Just use the external transistor and mosfet part and connect pin 1 to positive via resistor and pin 2 become output.
Not forgetting the diode needs to be changed to fast  response high voltage diode.

Hope you dont mind I modded your circuit just a little 
I wouldnt recommend anyone building this circuit, it will be very dangerous.
Also it might hurt a led 

[avalon]

The core that I am using is a standard 35mm dia core (35 x 22mm)

The secondary is connected in exactly the same way as in TK v1.4. I am not using 4049-based switch for now in my v2.0.
Different cores (I have tried about 40 so far) require different set of capacitors. The range is huge, from pFs to uFs.
I use an external breadboard to quickly change the capacitors.

The LEDs used are from my old 9W LED bulb. 3W, 1.5A
The diods are 1N5819

In order to find the core resonance I have made a pulse circuit (2 ch, IXDD609 driver + IRF640). My DG4062 is connected via LXI to a PC where I run a specially programmed VI (virtual instrument). One channel of the VI is sweeping frequencies and also triggering the second channel synchronously. In other words, I shoot different duty cycle pulses filled with other channel frequencies. The fill frequencies are in the range of 100 Hz to 60 Mhz.

So far I have found a specific pot core (35 x 22) that responds very well to roughly 125 kHz. This is the core I am using and it is the one that managed to produce hundreds of volts when tuned to the core frequency. Interestingly, I have 2 more cores which look the same but I can only get the response from one only. I have found that my E-core (ETD49) responds on 1.61 Mhz.

The coils are wound using a coil winder, so no scatter wound coils here. The secondary is first, then the primary.

~A