Pictorial Review of Power Supply Components

Pictorial Review of Power Supply Components

Here is a brief pictorial review of some important components seen in a power supply. Power transformer is one of the heaviest of the components and is used to step down the mains current voltage to the desired level for the power supply. It can have multiple secondary windings if more than one voltage levels are needed in the circuit. Size will depend on the power rating of the power supply.

Heat sink is needed for any semiconductor device which is likely to generate significant amount of heat. Sometimes a fan is needed to cool heat sinks of some devices like the central processing unit of a personal computer. Heat sinks typically take the form of aluminum fins on which the device to be cooled is mounted. Here you can see a device screwed on to the heat sink.

Large value filter capacitors of the order of thousands of micro farads are used to smooth out the ripples in the direct current output of the rectifier diodes.

Power cable is seen to be wound on a toroid at the place of entry into the cabinet. This will act as a radiofrequency choke, cutting of RF signals picked up by the power cable which can act as an antenna for RF signals.

Rectifier diodes have power and voltage rating as per the circuit demands. Larger sizes are needed for handling higher currents.

Higher values of inductances are needed as chokes in the rectifier circuits to further smoothen the ripple waves seen in the output of the rectifier diodes along with the high value filter capacitors. Physical size of the choke increases when higher currents are to be handled as thicker insulated copper wires are needed then.