This is a high voltage, low current power supply circuit which will give you high power voltage about 2000V output from 15VDC input.
A high voltage power supply can be a really beneficial source which could be properly utilized in a lot of applications like biasing of gas-discharge tubes and radiation detectors and so on. Such a power supply could also be utilized for protection of property by electric charging of fences. Here the electric current requirement is of the order of several microamps. In such an application, high voltage would basically exist in between a ‘live’ wire and ground. When this ‘live’ wire is touched, the discharge starts through body resistance and it provides a non-lethal but deterrent shock to an intruder. The circuit is built around a single transistorised blocking oscillator. An vital element in this circuit could be the transformer. It could be fabricated on quite easily available ferrite cores. Two ‘E’ sections of the core are joined face-to-face after the enamelled copper wire wound on former is placed in it.
Here the transistor winding:
2000V High Voltage Low Current Power Supply Source: