Working of miniature Tesla coil?
That is not a Tesla Coil. It is a high frequency oscillator. A Tesla Coil depends on resonance, which means a tuned circuit with a capacitor and an inductor. In the case of a Tesla Coil, it is two matched LC circuits (one with the primary capacitor and primary coil, and one with the topload and secondary coil). The above circuit just oscillates at a very high frequency based on feedback from the secondary coil (the one with 275 turns). When the switch is thrown the transistor turns on due to the current flowing into the base through the 22K resistor. Current also flows through the primary coil (the one with 3 turns), through the transistor, and back to ground. When you get a "burst" of current in the primary coil, it induces current in the secondary coil. The lower end of the secondary coil (assuming both coils have the same priority) provides a signal that turns the transistor off. When the coils discharge the cycle repeats (the transistor is turned back on again and another "pulse" is sent through the primary, inducing current, etc). This oscillates at a very high frequency which creates an alternating current output on the secondary coil. With a turns ratio of 3:275, a 9v input would give you about 825v (roughly speaking) on the output, based on normal transformer operation.;thank you