Joule Thief

Pirate88179 · October 14, 2009, 07:26:09 PM

@ Gary:

I understand what you are saying about when the battery state changes, it alters the circuit and it moves out of resonance. This make sense. However, what if you charged to a supercap, a large one, do you think the charge state of the supercap would alter the resonance the same as the battery? Or at all? If it doesn't, or if the effects of charge state is much less using the supercap, you could charge the large cap, or caps, and then periodically dump the full supercap into a battery which would otherwise be isolated from the circuit. This could be done fairly easily in an automatic manner but, I would not waste time on designing that unless/until you find that the supercaps keep the resonance of your circuit in tune despite the charge state.

Just a thought as I was thinking along these line with my Bedini experiments. I have not pursued this at all yet.

What do you think?

Bill

resonanceman · October 14, 2009, 08:12:41 PM

Quote from: Pirate88179 on October 14, 2009, 07:26:09 PM
@ Gary:

I understand what you are saying about when the battery state changes, it alters the circuit and it moves out of resonance. This make sense. However, what if you charged to a supercap, a large one, do you think the charge state of the supercap would alter the resonance the same as the battery? Or at all? If it doesn't, or if the effects of charge state is much less using the supercap, you could charge the large cap, or caps, and then periodically dump the full supercap into a battery which would otherwise be isolated from the circuit. This could be done fairly easily in an automatic manner but, I would not waste time on designing that unless/until you find that the supercaps keep the resonance of your circuit in tune despite the charge state.

Just a thought as I was thinking along these line with my Bedini experiments. I have not pursued this at all yet.

What do you think?

Bill

Bill

I have not done much with caps .... I have tried to use a cap a few times to see if I could remove the battery once I got to the self charging state .
IN each attempt the circuit went off pretty quick .

I think that the chemical reaction within a battery acts as a buffer .
With a cap .....no matter how big it is .......if you take a pulse out .....your next pulse is going to be smaller .

I have been thinking of ways around the resonance thing .
One thing I have been thinking of it having several levels .
Normal running might be at a certain voltage ..........but if you draw more power .....the voltage drops down into the resonance range of another JT ......or 2

The only way that I can think of to build this kind of layered system is to use a very accurate power supply that can deliver a specific current at different voltages .

I guess I should look into making a wall powered self charging JT ....... if it stays in resonance it will validate a few of my theory's

gary

jeanna · October 14, 2009, 08:34:25 PM

@gary,
Wouldn't your system stay reasonably tuned if you had a few batteries in parallel?

I have a few hours to play with any circuits when I use a AAA, but when I change them to AA with 4x the mAH's, the circuit changes very little for days.

In fact it is a part of my thoughts for future strategy.

A pair of D cells or a bunch of AA in parallel would light up my fluoro from the camera circuit for 4-8 hours without further modifications.

Can't this work for all of us in some way?

jeanna

resonanceman · October 14, 2009, 09:13:54 PM

Quote from: resonanceman on October 14, 2009, 08:12:41 PM
Bill

I have not done much with caps .... I have tried to use a cap a few times to see if I could remove the battery once I got to the self charging state .
IN each attempt the circuit went off pretty quick .

I think that the chemical reaction within a battery acts as a buffer .
With a cap .....no matter how big it is .......if you take a pulse out .....your next pulse is going to be smaller .

I have been thinking of ways around the resonance thing .
One thing I have been thinking of it having several levels .
Normal running might be at a certain voltage ..........but if you draw more power .....the voltage drops down into the resonance range of another JT ......or 2

The only way that I can think of to build this kind of layered system is to use a very accurate power supply that can deliver a specific current at different voltages .

I guess I should look into making a wall powered self charging JT ....... if it stays in resonance it will validate a few of my theory's

gary

Bill

I had an idea that might make caps or even batterys more buffered .

It involves connecting the cap or battery directly to a large depletion-type MOSFET.
The gate of this MOSFET would have a cap connected to it .
The gate cap would be connected to a diode or bridge .
The diode would be connected to an extra winding on the toroid .

This extra winding on the toroid should not take much power to run .
It is not exactly the JT circuit ..........but it will represent what is going on with the JT.
It should only provide enough power to get the cap charged to the working voltage of the MOSFET .
If you want more buffering ........ add more capacitance to the gate .

In short .......as the JT works harder ....... more power is induced in the extra winding ......the gate cap charges to a higher voltage ......and causes the MOSFET to increase in resistance .
When the JT is working less hard the gate voltage will drop and cause the MOSFET to decrease in resistance

resonanceman · October 14, 2009, 09:26:15 PM

Quote from: jeanna on October 14, 2009, 08:34:25 PM

In fact it is a part of my thoughts for future strategy.

A pair of D cells or a bunch of AA in parallel would light up my fluoro from the camera circuit for 4-8 hours without further modifications.

Can't this work for all of us in some way?

jeanna

Jeanna

I agree ...... larger batterys should greatly help the problem .
That is part of the reason I have been working on a 12 V system .
Another reason is with the right cores .......12V should provide much more power .

I have not had much time for expermenting lately ......
I did get a couple TIP3055s and I am looking forward to seeing how long it takes to fry them .

gary