Tesla Switch need help

[Thaelin]

   Looks like a problem with the ac type I have. They are zero crossing and I suspect that it will latch on and stay on. Not sure how I can get around this problem. Since I am using DC, it will never cross zero for the turn off. I need the MosFet type instead. $66 to find that one out.
   Now if I can do the same thing using plain mosfets, then I can still get it done. Have to tinker with it.

thaelin

[manokaiser]

Hi All!
I have read this thread and though it might be helpfull to a project I have in mind
for an e-bike.
If you have any idea of RC motors you'd know the standard configuration of
the circuit that runs those motors. Those are 3 phase motors operating through an
ESC (Electronic Speed Controller). The ESC takes DC input and pulses the waveform the motor needs to operate. We don't care if those motors are called DC or AC as it makes no difference to us.
Now what I am thinking is if we can possibly use an arrangement as in the picture
and switch between the two batteries with some sort of Tesla switch to get some power gain. I wouldn't talk of overunity but any possible gain in battery's runtime is highly desireable.
The parts are existing and any details one might need are available.
Motor ESC is up to 25V 100A. Motor can drag up to 50 A cont.
Batteries are of LiFePO4 type, (A123-Dewalt packs),
they can provide this kind of surge and they can be recharged very fast also.
Charger is able to feed up to 40A on to the charging battery.
As you realize we deal with real life application with high power involved.
Switching has to be appropriate, able to handle this power.
I would appreciate your thoughts and suggestions on it.
Regards
Manos

[Thaelin]

    Original tesla switch only has 12v potential between the batteries. That is why I have had such a pain in finding a motor that will work. There are 24v and 36v in hub motors all over  the place. Just dont have the power to work at 12v. Using the wiper motor at 2 amps, I am sending the unused power to the other set of batts not the positive pole. The cost is only the work done, heat and other losses. I even have a high and low speed.
   Even this motor will not run a long time as it was not meant to do this with. It is a proto use and will be justifying the worm gear setup to get the necessary torque to the wheel that is needed. I just finished the mounting of the gear to the motor and ready to mount to the bike. I will need to get 4 7.5amphr batts yet.
   Someone here on this board said that they believed that the answer would lie combining more than one type of unit to achieve the goal. I cant realize the batts staying charged but should go quite a ways on a charge.

thaelin

[manokaiser]

The RC motors come in any voltage you desire from ~6 volts to 36-40.
Each of them works in a wide range of voltages.
In my example 26 is maximum 12-24 is operational.
The ESC is taking DC and suplies the PW-Modulated current the motor needs to run.
You could use any of them as your load in the voltage you like.
They have decent efficiency (80% - 90+%) and in case of "outrunner" type,
huge torque for the size. Google it.

The most important questions are if the principles of this kind of switching are usufull,
universal and scalable.
If it would work somehow @ 12 volts, why wouldn't it work in a similar manner for other voltages?
Since Bedini used different chemistry and voltages I guess the trick would work for others too.
My schematic is very simplistic, only to show the logic, which I believe is basically the same as in different variations of the same theme as shown in this document
http://www.panaceauniversity.org/D3.pdf
A source battery is connected with the load and (in series with it) the charged battery .
Then we switch between the 2 batteries.
I have include the ESC and the charger box as are components of the arrangement I have in mind.
One could see the ESC-Motor combo as the Load and the Charger-Charged_Battery combo as the Charging battery of the original design.
Switching and the means of it as well as other components (diodes, capacitors) are
left out just to show the main idea.
So if you think it would work in a similar manner then we can proceed to figure out the details of it.
Thanks for replying, I appreciate!!

[allcanadian]

@all
You may find this interesting, what you are building is called a "charge pump" and can be found here---http://en.wikipedia.org/wiki/Charge_pump.
Here is a litte of the text--

A charge pump is an electronic circuit that uses capacitors as energy storage elements to create either a higher or lower voltage power source. Charge pump circuits are capable of high efficiencies, sometimes as high as 90-95% while being electrically simple circuits.
Charge pumps use some form of switching device(s) to control the connection of voltages to the capacitor. For instance, to generate a higher voltage, the first stage involves the capacitor being connected across a voltage and charged up. In the second stage, the capacitor is disconnected from the original charging voltage and reconnected with its negative terminal to the original positive charging voltage. Because the capacitor retains the voltage across it (ignoring leakage effects) the positive terminal voltage is added to the original, effectively doubling the voltage. The pulsing nature of the higher voltage output is typically smoothed by the use of an output capacitor.
This is the charge pumping action, which typically operates at tens of kilohertz up to several megahertz to minimize the amount of capacitance required. The capacitor used as the charge pump is typically known as the "flying capacitor".

The only diference is you are using batteries instead of capacitors, but batteries also have a much higher resistance than capacitors, leading to more losses in the system. I think in these kinds of systems we should use non-resistive loads such as solenoid coils which can then be phase matched with the circuit driver to produce high voltages and current flows in oscillation. In this case it could be said that we have a truely "reactive" circuit in that the phase differentials are not acting on the source and "work" is dissipated in only the load.
Just a thought

P.S.---- I just through together the circuit below based on the "charge pump", you may find it interesting.