What is the difference between linear regulated power supply and switching power supply?
A linear regulated power supply changes and controls its output voltage and current by altering the conductivity of transistors. In a linear regulated power supply, the transistor acts as a variable resistor and is connected in series in the power supply circuit. Due to the fact that the variable resistor and the load flow the same current, it consumes a large amount of energy and causes temperature rise, resulting in low voltage conversion efficiency. A common feature of linear regulated power supplies is that their power devices operate in the linear region by adjusting the voltage drop between the transistor poles to stabilize the output. Due to the large static loss of the adjustment tube, a large radiator needs to be installed to dissipate heat. Due to the fact that the transformer of the linear power supply operates at the power frequency (50Hz), its mass is relatively large.
Linear regulated power supplies are commonly used in low voltage applications, such as LDOs, which require a certain voltage difference to be met. The output voltage regulation rate and ripple are relatively good, the efficiency is relatively low, the required peripheral components are relatively few, and the cost is low. The circuit is relatively simple.
The advantages of linear stabilized power supply are high stability, small ripple, high reliability, and easy to make into a multi output continuously adjustable power supply. The disadvantages are large size, heavy weight, and relatively low efficiency. There are many types of stabilized power supplies, which can be divided into stabilized power supplies, stabilized current power supplies, and stabilized current (bistable) power supplies that integrate voltage regulation and current regulation. From the output value, it can be divided into fixed output power supply, band switch adjustment, and potentiometer continuous adjustable. From the output indication, it can be divided into pointer indication type and digital display type.
Switching power supplies are suitable for the full voltage range and do not require voltage differentials. Different circuit topologies can be used to achieve different output requirements. The adjustment rate and output ripple are not as good as linear power supplies, and the efficiency is high. Requires multiple peripheral components and high cost. The circuit is relatively complex. The circuit types of switch type DC stabilized power supply mainly include single ended flyback, single ended forward, half bridge, push-pull, and full bridge. The fundamental difference between it and a linear regulated power supply is that the transformer in the circuit does not operate at the power frequency, but operates at several tens of kilohertz to several megahertz. The power transistor does not operate in the linear region, but in the saturation and cutoff regions, that is, in the switching state; The switch type DC stabilized power supply is also named after this.
The biggest difference between a linear regulator power supply and a switching power supply is that in a linear regulator power supply, the transistor (whether bipolar or MOSFET) operates in a linear state, while in a switching power supply, the transistor operates in a switching state. Linear stabilized power supply and switching power supply are also named after this.
