PLz i need a circuit digram for switching mode power supply has an output 5V for a circuit contain Microcontroller and sensors and serial for interface.
The power adapter from an old cell phone would be perfect, depending on how much current you need. They are very small switching power supplies. It would save you the work of fabbing a custom circuit. Prettymuch all of them output 5V.
Hi,
As suggested, the simplest would be using a mobile phone charger. Another easy way is to use TNY, TOP or DPA switch from Power Integrations as the controller and a small number of accompanying parts to make the circuit.