SMPS and transformer are 2 different power supplies, but the working processes of these circuits are different.
the working of transformer power supply or linear power supply, the first step is to convert the 230 v ac to step down or up using a transformer and then its rectify using any rectifier diode.
but the SMPS is different, it rectifies the 230 volts first and it converts the dc signal to a high-frequency ac signal. after conversion, it will be regulated for the required voltage and current
SMPS vs transformer
| head 1 | Transformer power supply | switched-mode power supply (SMPS) |
|---|---|---|
| cost | cost is higher for comparing smps | switched-mode power supply cost is lower for comparing transformer power supply |
| size | it’s a size bigger compared to SMPS | it is smaller |
| Weight | Weight is high | is weight less than transformer power supply |
| efficiency | efficiency of transformer power supply is 60 % | the efficiency of SMPS is 80 % |
| circuit Complexity | simple circuits and using only a few components | complex circuits and using different types of components |
| Noise | transformer power supply has an only small amount of noise | the noise is very high |
| heat | it has only less heat because it has using a few components, so do not need any heat sink and another cooling system | the SMPS has used different types of semiconductor components, these components need a cooling system ex: heat sink, fan |
| Voltage regulator | some special voltage regulators are used to regulate the voltage | some complicated feedback circuit is used to regulate the voltage |
| Rf protection | It does not need any RF protection shield | RF shield required |
| application | • Low noise amplifiers • laboratory test equipment • battery charger | • used in vehicles • mobile charger • personal computers. |