What are the advantages and disadvantages of switching regulated power supplies?
Firstly, a regular regulated power supply, also known as a linear power supply, belongs to the series type regulated power supply. Its regulating tube operates in a linear amplification state. Generally, the greater the voltage drop of the regulating tube, the lower its efficiency. However, in order to ensure the normal operation of the regulating tube, a certain voltage drop is necessary. Therefore, we can see that the efficiency of a regular regulated power supply is relatively low.
A regular regulated power supply is a series regulated rectifier that uses a transformer to reduce voltage. The sampling circuit is used to control the conduction current of the power supply adjustment tube to change the internal resistance of the power supply, thereby stabilizing the output voltage. The efficiency of a series stabilized power supply is less than 50%.
The second type is switch mode regulated power supply, which can be divided into two types of circuits: series and parallel. It directly rectifies to obtain high voltage direct current, and adjusts the output voltage by controlling the on-off time ratio of the switch tube through a high-frequency oscillator.
In summary, in simple terms, a regular regulated power supply uses a sampling circuit to control the conduction of the power adjustment tube to change the internal resistance of the power supply, thereby stabilizing the voltage on the load.
A switch type regulated power supply adjusts the output voltage by controlling the on-off ratio of the switching transistor.
Advantages of Switching Voltage Stabilized Power Supply:
Advantage 1: Summary: Low power consumption, high efficiency, compact and lightweight
Its biggest advantage is that it has higher efficiency. The reason is that in the on/off state, the transistor itself consumes less function and can achieve an efficiency of 70-80%. At the same time, it does not require a step-down transformer. Its output transformer operates at high frequencies and has a volume less than 50 Hz for power frequency transformers. So the circuit of the switch type regulated power supply has the advantages of being compact and lightweight. It can operate normally over a wide voltage range.
Advantage 2: Wide voltage regulation range
The output voltage of a switch regulated power supply is adjusted by the duty cycle of the excitation signal, and the changes in the input signal voltage can be compensated for by frequency modulation or width modulation. In this way, it can still ensure a relatively stable output voltage even under large voltage changes in the power grid. Overall, the voltage regulation range of switching power supplies is very wide, and the voltage regulation effect is relatively good.
Advantage 3: Flexible and diverse circuit forms
For example, there are self-excited and separately excited types, width modulation and frequency modulation types, single ended and double ended types, etc. Power supply developers can leverage the advantages of various types of circuits to design and develop switch mode stabilized power supplies that can meet different application environments.
Disadvantage 1: Switch interference
Severe switch interference is the biggest drawback of switch stabilized power supplies. In a switch regulated power supply, the power adjustment switch transistor V operates in a switching state. The AC voltage and current generated by it generate spike interference and harmonic interference through other components in the circuit. If certain measures are not taken to suppress, eliminate, and shield these interferences, they will seriously affect the normal operation of the whole machine.
Disadvantage 2: The circuit structure is complex, the failure rate is high, and maintenance is troublesome. High maintenance and cost
