6 Battery Tesla Switch - Power Mosfet Circuit - Uses No Schottky Power Diodes

[BediniBattery]

Here is the Isolated 12 to 15 Volt Power Supply Circuit which is used to power each of the seperate mosfet gate circuits.

There are 13 circuits which need an isolated 12 volt supply, each of them has a seperate voltage regulator, rectifier & one secondary winding.

The voltage regulator is build using a single T0220 npn power transistor, a 5 watt 12 volt zener diode & 3k3 2 watt resistor.
A small heatsink is required for the transistor, the power dissipated is under 3 watts per transistor.
The recommended voltage regulating transistor is TIP31C as this has 100 Volts Collector Emitter Breakdown.

- http://www.rapidonline.com/Electronic-Components/Tip31c-To-220-100v-Npn-High-Volt-Transistor-Trusemi-81-0818 -
- http://www.rapidonline.com/pdf/81-0818.pdf -

There are two discrete voltage regulating stages, one is shown in the circuit below, while the other ones are shown in the mosfet gate drive circuits in part A & part B.

The mosfet gates should be driven to at least 11 volts to ensure they are turned fully on.

The ferrite toroid single mosfet switching circuit is not regulated as such but it does have a pulse width adjustment to set the output voltage under load.
The loading will be constant once all of the circuits are wired up. Once the pulse width is adjusted correctly, it does not have to be changed.
The output voltage should stay just above 12 volts under the full load of all 13 circuits.

The input voltage to the isolated power supplies must be voltage regulated in a similar manner as shown or you can use a mini switching regulator or any volt device.
The desired input voltage is between 11 to 12 volts.

[BediniBattery]

This is part E of the 6 battery tesla switch, which shows a simple technique to prevent over charging of the lead acid batteries by
means of reducing the battery switching frequency.

When the battery voltage exceeds 15 volts, the switching frequency is reduced considerably.
When the battery voltage falls below 14.4 volts the switching frequency increases to charge the batteries.

The exact turn on voltage can be adjusted using different zener diode values.
The zener diodes are all 0.5 watt type.

A small 100 uF capacitor is placed on the pcb close to the 555 timer, to eliminate any spikes & to slow down any frequency changes.

Battery 3 & Battery 6 both have their negative terminals connected to 0 Volts so it is easy to measure their potentials accurately.

They are shown in diagrams A & B.

To measure two batteries at the same time, use a seperate 10 K resistor & zener diodes & onboard capacitor, but use the same transistor (OR Gate).

The positive terminals of Battery 3 & Battery 6 must not be connected together because one is part of the charge circuit & the other is part of the discharge circuit.

The discharge & charge batteries must be seperated, however their battery potentials can still be measured accurately while in operation.

This gives the basis of a self regulating tesla switch charge circuit.

[BediniBattery]

This shows how to connect battery 3 & battery 6 to the voltage controlled oscillator.

An improvement from Part E

[BediniBattery]

Zipped BMP schematics & ExpressSCH Files for 6 Battery Tesla Switch Without Diodes.

- http://www.mediafire.com/?5xuh3fpu8f472n2 -

There are no pcb design files yet only schematics(22 April 2012).

Slide Show : - http://universallyaware.ning.com/photo/photo/slideshow?albumId=6049518:Album:130417 -

I am currently designing the Tesla Switch PCB using electronic workbench UtilBoard 8.
A single sided board measuring 203 X 305mm will be required to build the basic switching circuit & over charge protection circuits.

- http://www.rapidonline.com/Tools-Equipment/Low-cost-copper-clad-board-32634 -

The main board will control the mosfet switching & provide all of the 12 volt isolated power supplies to each individual section of the circuit.

I have decided to wire up each mosfet gate circuit using 0.1" or 0.156" PCB Terminal Connectors.
This will allow the board to be constructed more easily & will enable fault finding to be done quickly.
There will be quite a lot of manual wiring up to do on the board itself.
A 10k resistor should be soldered between the mosfet gate & source to keep it turned off while the gate drive cable is disconnected from the board.

I have completed the majority of the schematics, I would advise everyone to wait until I have uploaded a working pcb layout as it is quite complex.

[BediniBattery]

Power Rectifier Diodes - Forward Voltage Drops & Peak Inverse Voltages


Here is a list of parts that I recommend using for building various switch mode power supply devices, or pulse charge circuits for charging batteries.

The most important component will usually be a rectifying diode, mosfet & ferrite or iron dust toroid.

Whatever circuit you are building, take a close look at which diodes you choose to put in your circuits.

Here are the results of forward drops taken across a number of different diodes during a 0.4 amp load current.

If you want to use a diode for zener voltage regulation purposes, the forward voltage drop cannot be relied upon.

Not all schottky diodes are the same.

The same situation is true of magnetic toroids, as there are so many of them & they all have different characteristics.

Some work better than others, but you won't know until you test it practically.


Download the data sheets here :

Zipped Files & Data Sheets- http://www.mediafire.com/?a654ryazyx68w -


MBR2045CT - Forward Volt Drop = 0.357 Volts - Peak Inverse Voltage 45 Volts - 20 Amp


60CTQ150PbF - Forward Volt Drop = 0.380 Volts - Peak Inverse Voltage 150 Volts - Dual Schottky Rectifier - 60 Amp

http://www.rapidonline.com/Electronic-Components/60ctq150pbf-Dual-Schottky-To-220-47-3650


1N5819 - 1A Schottky Diode - Forward Volt Drop = 0.402 Volts - Peak Inverse Voltage 40 Volts - 1 Amp

http://www.rapidonline.com/Electronic-Components/1n5819-Schottky-Diode-40v-1a-Do-41-47-2566


BYW80 150 - Forward Volt Drop = 0.663 Volts - Peak Inverse Voltage 150 to 200 Volts

http://www.rapidonline.com/Electronic-Components/Fast-recovery-diodes-65308/?sid=7dd16922-7b8a-415a-b906-77a6db45a57a


1N4001 to 1N4007 Silicon Diodes 1 Amp - Forward Volt Drop = 0.858 Volts

http://www.rapidonline.com/Electronic-Components/1n4002-1a-100vsilicon-Rectifier-Diode-47-3132


500mW BZX55C Zener Diodes for Voltage Regulators

http://www.rapidonline.com/Electronic-Components/500mW-BZX55C-Zener-diodes-Vishay-67267


13 Volt Combinations - 6v2 & 6v8 or 4v7 & 8v2 or 3v0 & 10v

13 Volt Zener Diode

http://www.rapidonline.com/Electronic-Components/Bzx55c13-13v-500mw-Zener-Diode-47-3034


N - Type Power Mosfet

IRFP064N - TO-247 Package

VDSS = 55V
RDS(on) = 0.008R
ID = 110A

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l2736&_nkw=IRFP064N


P - Type Power Mosfet

IRF5305

VDSS = -55V
RDS(on) = 0.06R
ID = -31A

http://www.ebay.co.uk/sch/i.html?_nkw=IRF5305&_sacat=0&_dmpt=UK_BOI_Electrical_Components_Supplies_ET&_odkw=IRFP064N&_osacat=0&_trksid=p3286.c0.m270.l1313


NPN Power Transistor - TIP31C

T0220C Package
DC Current Gain -hFE = 25(Min)@ IC= 1.0A
Collector-Emitter Sustaining Voltage : VCEO(SUS) = 40V(Min)- TIP31; 60V(Min)- TIP31A 80V(Min)- TIP31B; 100V(Min)- TIP31C

Complement to Type TIP32/32A/32B/32C

http://www.ebay.co.uk/sch/i.html?_nkw=TIP31C&_sacat=0&_dmpt=UK_BOI_Electrical_Components_Supplies_ET&_odkw=IRF5305&_osacat=0&_trksid=p3286.c0.m270.l1313


Light Green Ferrite Toroid

http://powermagnetics.co.uk/pace-components/ferrite-cores/ferrite-toroids/tr-25x15x12c-cf199

TR-25x15x12C-CF139 - £0.73

25x15x12mm ferrite toroid - Coating: Epoxy
Manufacturer: Cosmo Ferrites
Material Grade: CF139 (Equivalemt to Ferroxcube 3C90 / 3C94; Epcos / Siemens N87; TDK PC44 )

Dimensions:

Outside Dia: 25mm
Inside Dia: 15mm
Height: 12mm
Weight: 19.0g

Magnetic Characteristics:
uiac = 2100
AL Value = 2450 - Permeability
(+30%/-20%)