Here is a Short-Circuit Protection circuit to derive the additional power supply from the main circuit. The main circuit is protected from any damage due to short-circuit in the additional power supply circuit by cutting off the derived supply voltage.
The derived supply voltage restores automatically when shorting is removed. An LED is used to indicate [...]

You can use this power supply for your electronics project which only require electric current about 500mA. This is cheap circuit which will give you stabilized output voltage.
If you want to change the output voltage, you should change the IC type.
For example, you need 5V output, then change the IC from 7098 with 7805 dan [...]

This is a simple low-cost 12 Volt 50W off-line switching power supply, which can be used for home projects or to learn operation of flyback converters. It can work over a universal AC line input range 90-264 VAC and provides a 12VDC output at more then 4A load. Line and load regulation is better then [...]