How much voltage does a 30kv fly back transformer need to put out 30kv?

how much should the input voltage be for it? Cause I heard that 120AC can destroy it. I need to know. thanks

You don't run a FB transformer off the line. You make its primary part of an oscillator. You apply volts on the primary and the current in it starts to ramp up, storing energy in the magnetic field around the core. After a few hundred MILLIONTHS of a second, you turn OFF the voltage very quickly, and the collapsing field induces a high VOLTAGE in the secondary. Its called a flyback transformer, because it forms the classical line scan in a CRT TV. Typical applied voltages are fairly low, but it MUST be controlled as I said.
Mudbud (author)  steveastrouk8 years ago
so does that mean I can use 35VDC to power it? or 16VDC?
Yup. Exact results depend on your transfomer, but you'll definitely get some output.
appolo8 years ago
Flyback transformers are used in CRT based monitors and TV sets. The transformer a dual role purpose in providing the necessary EHT voltage for the CRT final anode (30KV) plus various other secondary supply voltages. All this comes about from the line scan output device_a high power switching transistor which switches at line scan rate. As the CRT is scanned line by line the eht voltage is generated during the line flyback period (when the CRT is not being scanned) the voltage feed on the primary and scan output transistor is generally in the order of 120volt _ 200volts DC. (voltages can vary dependent on design) Look up TV line scan output stages for more information. So to sum up the input primary voltage is HT _ high tension DC and the switching action of the output device at line rate creates a pulsed ouput during flyback. Hope this helps.