H.V. Supply
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Elektronik Design LABoratoriet

The Tesla HV Supply THV40K12:

The aim with this supply is to abide to the Tesla discovery: A High Rate Of Change.

The supply utilizes modern HexFet and other fast components.
These components are capable of high speed, high voltage switching. By combining high
voltage and high frequency, the highest possible Rate Of Change is achieved.

The THV40K12 supply consists of 2 parts:

1: Base supply TBU12V25KHz
2: HV coil

The Base Supply:
A 12 volt DC is chopped and elevated to 400 volt at 25KHz square wave.
Max power output is 25 watts.
Weight is 350 grams (0.35 kg).
Size is 125 * 88 * 70 mm.
TBU12V25KHZ AC output curve TBU12V25KHZ AC output curve.
Rise time < 1µsec.

The HV coil:
A Tesla style HV coil elevates 400v to 40KV
The coil delivers only minute currents. The output is therefore of a 'static' type
although it oscillates at 25KHz square wave.

As the voltage rises from 0 to 40 KV in 1µSec, voltage rate of change is 40 billion volts per second.
A maximum rate of change of current of 10A/µSec combined with 40KV gives a power rate of change of 4KW/µSec which is 4 billion Watts per second.

Additional circuits:
The Base Supply alone may be combined with the CDI circuit and an ignition coil to obtain a
powerful CDI ignition equipment.
The sparks from such a CDI ignition system may be used to supply vehicle ignition or other
purposes where a controlled spark frequency is needed.
With a standard 12V ignition coil, high energy voltages of 20KV may be generated.

Gunnar Jespersen, Electronics Design Engineer.
Email: gunnar at carl-fh.com