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Author Topic: 6 Battery Tesla Switch - 720 Watt + New Solid State Mosfet Circuit Designed  (Read 20401 times)


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6 Battery Tesla Switch - 720 Watt, 30 Amp - Lead Acid Battery Free Energy Circuit

The circuit uses a total of six, 12 volt lead acid batteries to power the load.

3 batteries are wired in series to create 36 volts.
The total discharge current is 30 Amps.

3 batteries are wired in parallel to create 12 volts
The total charge current is 10 Amps per battery.

20 Amps are lost to the environment as heat or work done by the load.
This is the amount of energy that the environment needs to replace to keep the tesla switch running.

A switching circuit is used to set the frequency by which the batteries are changed from series to parallel.
When the switching frequency is high enough, the battery voltage should begin to increase under load.

The copper wiring must be constructed from hundreds of thin copper strands, whilst keeping the circuit resistance to an absolute minimum.
All of the connectors should be high quality copper or silver.

The output voltage across the load will be approximately 24 volts, & this will have to be regulated in someway using the 555 switching circuit.
The capacity of the batteries should be upwards of 40 amps, a small car battery is suitable.
The batteries need to deliver 30 Amps through the load, while only getting 10 Amps charging.
All of the batteries should have equal capacity & be in good condition.

The mosfet drive circuits use isolated 12 volt regulated supplies which can deliver 50 mA.
Dc to dc converters are available ready built, but you can make your own if you need more control over the circuit.

The n type mosfet gates are driven between 0 volts & + 12 volts using transistor pairs, in the push pull fashion.
Logic mosfets do not offer any advantage in this circuit, but they can be used if the gate voltage is held within its maximum swing.

You can place many n type mosfets in parallel to reduce the circuit resistance.
The push pull technique enables very fast charging & discharging of the mosfet gate capacitance, so paralleling mosfets is not a problem.

The heatsinks you use on the components should reflect the amount of continuous current they will carry.

On the diagram it shows 30 Amps & 10 Amps for the diodes, which might give you some idea where to place more mosfets in parallel.
Reducing the circuit resistance is a real priority.

Since all of the circuit components are constantly switching & are only being used 50 % of the time, this means
that a 30 amp diode is only working at 50 % of its rated capacity.

Twice the amount of power output is actually available, but only if the circuit resistance can be reduced to less than 0.1 Ohm.
The circuit is capable of delivering 60 amps of current through the load in theory & delivering 1440 watts of power at the maximum.

You should avoid making higher voltage tesla switches as it becomes difficult to get hold of suitable components & the cost rises.
You may be able to use this circuit to build switched capacitor charging circuits, which work in the same way as the tesla switch.

The opto isolator used in the circut diagram is the 4N25.
It is essentially a normal npn transistor, which is controlled entirely using an internal LED.
The resistor values on the 4N25 collector are between 2k2 to 3k3.
The internal LED requires a 1K or 470R, however this must be chosen depending upon the switching frequency.
The base of the photo transistor is left unconnected.
Even though the 4N25 is a slow device, it has been tested to function properly between 100 to 1Kz.
There is no need to use a schmitt trigger opto coupler device.

A number of opto isolator transistors have been placed in parallel.
This is to make absolutely sure that none of the mosfets can turn on at the wrong time.
There is a very short time delay between switches, which is controlled entirely by the transistors themselves.
The switching delay is automatically controlled & lasts 1 micro second.

The transistors used are : npn BC547 & pnp BC557.
The schottky power diodes are stud type, such as SD51.
The mosfets are all n-type with 50 Amp + drain to source current rating, very low on resistance with 55 volt working voltage.
The mosfets have integrated zener diodes which do not interfere with the circuit operation.

Mosfets A,B,F,G are placed backwards in the circuit & are driven in exactly the same way as the other n type mosfets.

When the mosfet is turned fully on, +12v gate to source, there is very little voltage drop across the mosfet & it behaves like a switch.
When the gate is shorted to the source terminal, the mosfet stops conducting & no current flows.

The mosfets source & drain terminals have been reversed because the internal diode interferes with the intended circuit operation.
Even though this is a strange circuit to construct, the mosfets behave perfectly well when placed into the tesla switch circuit.
You cannot normally do this in an ordinary switching circuit because the body diode will short out the supply.
There doesn't appear to be any reverse voltage evident across the drain & source, in the series battery configuration.
There is no current flow through the mosfet body diode, so all of the current flow will be through the mosfet channel only, when the gate is held high.
All of the mosfets are rated at 55 volts drain to source.

A number of 12 volt zener diodes have been placed on the base of the push pull circuit, this is to further regulate the 12 volt supply voltages.
The mosfet gate drive supply voltages can be clamped using zener diodes, transistors or 10 watt resistors.
The total circuit uses about 5 watts of power, even when using clamped switched isolated supplies.
Any power used by the circuit will be provided by the free energy circuit.

Part A & B Circuit Diagrams Shown Below.

This has taken me several months to design, so give this circuit a try if you have the parts available.

Download Tesla Switch Files  - -


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6 Battery Tesla Switch - 720 Watt, 30 Amp - Lead Acid Battery Free Energy Circuit

...The capacity of the batteries should be upwards of 40 amps, a small car battery is suitable...

...The circuit uses a total of six, 12 volt lead acid batteries to power the load...

Does it mean that the system does not work with smaller Lead-Acid batteries? What about non - Lead-Acid ones?
Good work, anyway.


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Battery Capacity & Practical Considerations
« Reply #2 on: April 06, 2012, 01:32:51 PM »
I have used 40 Amps as the minimum battery capacity for practical reasons.

One reason is obviously the need to have large battery terminals & a battery that can deliver that amount of current.

This circuit is intended to be used primarily with lead acid batteries.

You can try the circuit on different battery chemistries & try using smaller batteries, but reducing the current in the circuit might stop the self charging effect.
When driving small loads & using low power batteries, you might get self charging under load by increasing the switching frequency, but there are no guarantees.

All of this is theory at the moment, however the basic electronic switching part has been practically tested & it works.

The circuit can used as the basis of a switched capacitor dc to dc converter.
The circuit switches 12 volt batteries, but capacitors can be used in their place. 

I will have more practical test results in few weeks.

I still have to design a pcb for the circuit as it is quite complex to wire up.

Visual LEDs can be placed anywhere in the circuit provided you do not parallel any of the components, use a seperate resistor & connect to the push pull outputs.
Slowing down the 555 timer astable will allow fault finding to be done since the circuit behaves as an astable oscillator.

- I will be posting the isolated 12 volt regulator circuits next.


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Thanx for good work and for response.


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Thanx for good work and for response.

I have made another circuit which doesn't use any schottky power diodes.

Diodes are not very helpful when you want to keep the circuit resistance to a minimum as they produce lots of waste heat.

This circuit is built using power mosfets only, with no diodes in the high current path.

This means more current can be handled by the circuit & more free energy can be created.

The photo diodes circuits have also been improved by placing many diodes in series reduces the power consumption.