When it comes to electrical and electronic circuits, it is crucial to have a power supply that delivers the exact amount of current and voltage required for the circuit to run, without exceeding the limits. There are two most common types of power supplies – coil (or linear as it is more popularly called) and switched mode. Although both these power supplies supply DC power, they differ in the way they produce the power and in the way they operate. Depending on the application they are used with, both the power supplies have their own advantages and disadvantages.
How do these power supplies work?
A switch mode power supply (SMPS) converts the AC line power directly into DC voltage, which is then converted into a higher frequency AC signal. This signal is used in the regulator circuit to produce the desired current and voltage. Therefore, SMPS is a much smaller and lighter transformer that adjusts the voltage as required, which results in higher power conversion ratio. On the other hand, a coil/linear power supply applies the AC line voltage to a power transformer to lower or increase the voltage before being applied to the regulator circuit. This requires a larger and heavier power supply.
What are the advantages of SMPS over coil power supply?
- SMPS is as much as 80% smaller and lighter as compared to an equivalent coil power supply.
- SMPS can withstand small losses of AC power in the range of 10-20 ms without affecting the output, which coil power supply cannot.
- Coil power supply requires larger semiconductor devices to regulate the output voltage, which in turn generates more heat, resulting in lower energy efficiency. Coil power supply has 60% efficiency where SMPS can have up to 80% efficiency under the same conditions.
What are the advantages of coil power supply over SMPS?
- SMPS generates high frequency noise that can interfere with sensitive electronic equipment, while coil power supply is relatively quieter.
- Coil power supply is simple, where the regulators exist in packaged ICs that only need a rectified voltage source to operate. Conversely, SMPS is very complex and requires a number of ICs and inductors.
Therefore, the main advantages of SMPS are its small size, light weight and better efficiency, while the only disadvantage is the noise it creates. As a result, SMPS is better suited for portable equipment as it is lighter and more compact; while coil power supply is best suited for powering sensitive analog circuits due to the lower noise produced.
When selecting a power supply, a durable and reliable solution is important to ensure quality and safety. The quality of the transformer in terms of specification, performance and durability are very important considerations. Miracle Electronics’ SMPS transformers are significantly designed to achieve these objectives. They have a very high power-to-size ratio and each segment has a unique V-in to V-out transfer function that leads to amazing efficiency. This is why Miracle Electronics is rightly said to be the best SMPS transformer manufacturer in India.