RE-EMF Charger

[Blargus]

To get this effect I just added an antenna to the base of the transistor. This antenna is only about 20 feet total and goes out my window after the first 5 feet. I think it would probably work even hanging around in a room.

Hi, read this on Steve jackson's wireless power transmission group, it's basically a two pancake coil setup tuned to resonance:

"When I move my hand about the globes the signal and tune change. When I simply attach a 12" wire to any of the terminals the tune changes. And so, moving the setup outside and attaching it to ground could change the tune frequency considerably." Pryer

So maybe your antenna changes the resonance of your circuit?

Still working on the Re-Emf
Mike

[ewizard]

I just found another interesting thing for this circuit. It caused the o-scope pattern to jump about 5 times higher in the spike. It's not only higher but a different pattern that looks to me like it will charge even better and faster. It's still essentially a square wave with a spike on top of the upper left square and more solid looking all the way around. To get this effect I just added an antenna to the base of the transistor. This antenna is only about 20 feet total and goes out my window after the first 5 feet. I think it would probably work even hanging around in a room.

OOOPS!!! I made 2 dumb mistakes in the post above. I've got a couple wires coming into my room that look alike and as it turns out I was not using the Antenna wire but rather I was using a ground wire. This is a separate ground wire from the grid as I put in an 8 foot copper clad pole into the ground outside my window. While it is not tied directly to the ground rod for the house wiring it is probably essentially the same.

Secondly I did not connect that ground to the Base as stated above but rather it was hooked to the Collector of the transistor. Since finding these mistakes I also tried using the house electrical ground on the collector and while it causes a similar higher o-scope pattern with some spikes they are not as big as they are with my separate ground. I am really liking this circuit and managed to recover yet another small lead acid battery. That battery had been on a good 10 amp / 2 amp smart charger for a couple days using both 10 and 2 amp but it would not recover. I put it on this charger for 2 days and it was good to go. This circuit has proven itself well enough now that I soldered everything up and put it in a project box. BTW great and very cheap project boxes are those electricians plastic outlet boxes which you can find at major hardware stores for around 20 to 30 cents each.

[boguslaw]

I asked about the capacitor right after the diode bridge because I know that lead acid batteries likes to be charged from pulsating DC current. If this capacitor is low enough then the main current going into battery would be very pulsating , but if it's of large capacity then current should be steady DC. Don't know which one is better in this circuit.

[gyula]

I asked about the capacitor right after the diode bridge because I know that lead acid batteries likes to be charged from pulsating DC current. If this capacitor is low enough then the main current going into battery would be very pulsating , but if it's of large capacity then current should be steady DC. Don't know which one is better in this circuit.

Well, the diode bridge and its puffer capacitor is an alternative power source from the mains to feed the EMF charger circuit, ok? So you need to use it ONLY in case you do not wish to run the circuit from a run battery of 20V as is shown in the schematic in the very first post of this thread.
So a more or less steady DC is needed to feed the circuit, the puffer capacitor value could be some thousand microFarad.

[Wistiti]

...

these charger Rock's!

Try the improvement of the joule thief shown in the last PJKbook update (Thank you Pat!) Put led in series on the base of the transistor...

Ciao!

[ewizard]

After getting my setup all boxed up (exept for the bifilar toroid) I decided to try several other bifilar toroids as the one I'm using for this setup is a large 4" diameter toroid that I didn't want to limit it's use to just this charger. It's too big anyway for my project box. I tried a couple other bifilar toroids I had that I wound on about 1.25 to 1.5 inch ferrite toroids. I also tried a bifilar pancake toroid (air core). None of these other units worked at all. No spikes, no square wave or anything that would do well at charging. I was hoping to find a smaller toroid I could put inside the box but no luck so far and I'm somewhat surprised by the lack of any good output with these other toroids. These have worked okay with joule thief's in the past.

Maybe I got lucky with the big toroid in hitting some resonance of some sort. I think anyone trying this circuit may want to put it on an o-scope if you have one to make sure you are getting some good spikes on the output.

[shingot]

Application of Rene's variant

i think rene's variant can be applied to any existing joule thief or bedini setup. i just converted my 7-filar bedini solid-state into this.

regards,

shin

[brian516]

i think rene's variant can be applied to any existing joule thief or bedini setup. i just converted my 7-filar bedini solid-state into this.

regards,

shin

I noticed this thread the other day myself and built one. Didn't think anyone else was messing with it anymore since the last post before yours was something like two years ago.
I would like to point something out to you, however....
There is a huge problem with this device - most battery chargers, if not all, push intermittent DC into the batteries when charging, as not to boil the battery and cause it to overheat or explode. This device puts a constant DC into the battery before running the circuit and pulsing the battery. It doesn't matter how low you set your mA input draw to, it heats up the battery and will potentially destroy it. It has already caused one of my 6V 4.5Ah batteries to leak acid, and has burst 4 Alkaline batteries.

Other than that, it seems to do a good job charging, but my suggestion would be to shut it off every 5 or 10 minutes for 5 or 10 minutes... maybe set up some sort of timer circuit to it, or modify it so it pushes pulsed DC from the primary to the charge battery before running it to the circuit, and maybe put some sort of cap setup after the charge battery to keep the power running smoothly into the JT circuit.

I have no idea if this idea will work, since I'm far from an electronics whiz, and don't know enough yet to be able to design my own simple circuits, but I just wanted to point out my observations/experiences with this device before you go popping some batteries of your own.

Also I would just like to add that it could very well be possible that I did something wrong and as a result, 'blew up' some batteries, however I did follow build specs to the T. Only difference in my device is that I am using the MJE3055 instead of the 2n3055, because I don't have any heatsinks for the T03 style transistors and didn't feel like making any. I don't believe there is any real difference in the specs between the two. Maybe I just left them on too long, esp since I left the 6V on overnight, even though it was on very low amp draw.... really just enough to keep the pulse circuit on overnight....

-Brian