Recently I came accross an interesting ignition coil. It is not an ordinary coil the high voltage maniacs play with for tens of years. Interestingly it is that it has a built-in switch (power transitor) and a drive and protection circuitry. It is sometimes called Integrated driver ignition coil. It can therefore be connected directly to the output of the famous 555 integrated circuit oscillator to make an extremely simple high voltage power supply. It is designed for 12V. Output open voltage is 30-40kV (sparks 3-4 cm). Secondary resistance is 6k. When increasing the frequency of the output voltage remains constant up to about 300Hz, then it falls. The current consumption of the circuit diagram below in about 3A at 12V. The ignition coil has an iron core with an air gap. My coil is a Z04 type, made by VAPE Kromeriz. coil could be used as a simple electric fence (on your own risk).
