ac to dc adapter (commercial circuit) explain

hi,

i have made small DC power supply for my project use.

But recently i have open an AC/DC Adapter which has the little complex circuit.

i dont know why other component needed in this circuit???

can any expert explain it to me.. why so many things needed in this type of circuit???

It looks like what you've got hold of there is a SWITCHING power supply. They are more complex than the linear supply you probably made, but they are more efficient. You can find lots of information on the web to explain how these supplies work.

The fundamental difference is that the POWER(not current) into a switching supply is the same as the POWER out of the supply, less losses due to inefficiencies in the circuit, whereas with a linear regulator the input and output CURRENTS are the same, which means that you lose (Vin-Vout) * CURRENT in heat. For low currents, linears make more sense but as current requirements go up, the switching topology makes more sense. (Switchers do have the negative effect of generating a lot of electrical noise, which can be a problem in low-level circuitry.)

thank you so much.

I have google about the switching power supply. it is more efficient.

can you tell me the efficiency of the linear power supply??

is it practical to make 24V and 1A switching power supply as project??