In order to understand computer power supply we must first dissect it into parts for a better understanding. it has the following parts :-
In the computer power supply just like any other power supply power comes in via the port where there is a voltage selector. Depending on the power supply, you get to choose voltage which is either 220-240V A.C or 110-130V A.C which depends on the country you are in i.e for example in the U.S.A they use 110V while in Kenya they use 220V.
Once you choose the voltage you can either use back to back voltage for the monitor or power the monitor from a different outlet. once you are done with that the voltage passes through a passed to a transformer where it is stepped down to various voltages.
The voltage is hence passed through a rectifier which can be either half wave or full wave depending on the number of diodes, 2 or 4 respectively. This diodes then change the voltage from A.C to D.C
The voltage is then filtered by capacitors and later stabilized by means of a regulator to produce a steady d.c voltage with no rolling sound. This power supply process will be further explained in my electronics page.
The voltage is then transferred to various computer components by means of sockets. The sockets supply varying voltages on the computer and can be viewed in more detail below :-
On the motherboard the pins are either 20 pin or 24 pin depending on the computer type. This are transferred to different circuitry to power various components.
In order to start a power supply without a motherboard you can just short circuit the green and black terminals i.e (PS ON & GROUND) as below:-
The A.T.X power supply as above in comparison is also similar to sata i.e serial ATA except for different ports:-
This power supply have many fans for cooling purposes. More in depth explanation of the inner workings of the power supply will be covered in my electronics page.