Playing with a high-voltage arc generator kit that uses step-up transformer with a simple feedback control of a D882 power transistor.
Here's a quick demo..
This is a version of a very common High Voltage Arc Kit. It is basically a step-up transformer with a simple feedback control of a D882 power transistor. It is actually a demonstration of the same circuit used on "plasma lighters".
- Input Voltage: 3.7-4.2V
- Input Current: <= 2A
- Output Voltage: <= 15kV
- Output Current: <= 0.4A
- High Voltage Polarization Ignition Distance: <= 0.5cm
The Basic Circuit
I redrew the basic schematic here in EasyEDA.
bigclivedotcom did a tear-down of a commercial "plasma lighter" and no surprise, it uses the same circuit as demonstrated with this kit.
This is a simple circuit with few parts - most of the magic happens in the transformer windings.
Interestingly, the kit I purchased contained two of each transistor, diode and resistor. Have they learned that people who buy HV arcs are more than likely to smoke at least one part?!!
|15KVE-1 Step-Up Coil||1||3 windings|
|470Ω resistor||1||2 x 470Ω supplied. Other versions of this kit use 120Ω or 200Ω|
|FR107 Diode||1||2 supplied|
|NPN Power Transistor||1||2 supplied. Unmarked, but appears to be D882|
|Insulated Wire||2||for power connector|
|Heatsink||1||for transistor, with mounting nut & bolt (nut is not actually required as the heatsink has tapped mounting hole)|
|heatshrink tubing||3cm||presumably to insulate connections if built ugly style|
Many of the kits currently available seem to have been upgraded slightly, to include a switch and PCB.
Step-up Transformer Details
|Primary||17µH||thicker magnet wire|
|Feedback||27µH||thinner magnet wire|
|Arc/secondary||1.5H||mounted opposite the primary and feedback windings|
The primary and feedback windings come with the ends to be connected to the positive power supply already wound together. This hopefully ensures correct connections!
I used a 5cm x 7cm piece of single-sided protoboard to mount the kit, adding:
- push-button switch
- 5.5 x 2.1mm barrel jack for power supply
Works just fine. With a supply of 5V, it draws around 1.6A during arc.