What is switch mode power supply (SMPS)?

The switch mode power supply (SMPS) is an electronic device which used as switching regulator. It is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. Operated in either cut-off or saturation switched mode.

Working of SMPS:

Working of SMPS

Input Rectifier and filter:

The input rectifier receives an unregulated AC power supply from a main supply and converts into DC ripple. The output of rectifier is given to the filter. The filter removes the ripple factor of rectifier output and provides a pure DC.

Inverter “Chopper”:

The inverter receives the rectified DC output and convert it into A.C. by applying it to the power oscillator whose transformers output has a frequency of 10 or 100 kHz. By MOSFET switching is done.

Output transformer:

The transformer which receive an A.C. signal and step up or step down the output voltage. The ON and OFF duty cycle of the devices on which the output is dependent is set by the pulse width modulation (PWM).

Output rectifier and filter:  

The output rectifier receives the A.C. signal from the transformer and converts it into ripple DC. The filter removes the ripple present in the rectified output. The schottky diodes are used as rectifier elements for low output voltage and silicon diodes are used for higher voltage.

Chopper controller:

The chopper controller is used to compares the feedback from the output voltage to the reference voltage. If any error is present than its compensated by adjusting the switching timing of the MOSFET which acts as switching regulators.

switch mode power supply (SMPS)