he universal input power supply shown in Figure above has multiple outputs, ±26 VDC, ±15 VDC, and +5 VDC. The ±26 V outputs can each deliver a minimum output current of 2.42 A peak (thermally limited) and 1.45 A continuous. Additionally, the voltage regulation and, importantly, transient response is excellent over the entire load range [...]

The Supertex HV440 is used for implementing a pulse width modulated high voltage ring generator for telecommunication applications. The HV440 can operate in both closed-loop or open-loop. A closed-loop design is more complex but provides better load regulation and lower THD compared to an open-loop design [...]
Source: http://www.supertex.com/pdf/app_notes/AN-H37.pdf

If you need a simple high voltage generator circuit here is your.The peak output voltage will be approximately 15,000 to 20,000 volts, but this will vary with the ignition coil type and the voltage at which the MOV starts conducting. Do not touch any part of the 555 circuit including any leads of the timing [...]