What Is the Classification and Principle of Switching Power Supply?
Different kinds
DC-DC converter
Forward converter
Flyback converter
Self oscillating flyback converter
DC-DC converter
The primary power received from the AC main power supply is rectified and filtered into high voltage DC. Then, it switches at a huge speed and is fed to the primary side of the step-down transformer. The step-down transformer is only a small part of a similar 50 Hz device, thus reducing the size and weight problems.
We have filtered and rectified outputs on the secondary side of the transformer. It is now sent to the output of the power supply, and the output sample is sent back to the switch to control the output voltage.
Forward converter
In the forward converter, the choke carries current when the transistor is on and off. The diode carries current during transistor shutdown. Therefore, in both stages, energy flows into the load. The choke stores energy during energization and transfers some energy to the output load.
Flyback converter
In a flyback converter, the magnetic field of the inductor stores energy during switching on. When the switch is off, the energy is emptied into the output voltage circuit, and the duty cycle determines the output voltage.
Self oscillating flyback converter
This is the simplest and most basic converter based on flyback principle. During the on time of the switching transistor, the current through the primary of the transformer begins to rise linearly, and the slope is equal to VIN / LP.
The voltage induced in the secondary winding and feedback winding quickly restores the reverse bias of the rectifier and keeps the conductive transistor on. When the primary current reaches the peak IP, the magnetic core begins to saturate and the current will rise sharply. The fixed base driver provided by the feedback winding cannot support the sharp rise of current. As a result, the switch begins to disengage from saturation.
Basic working principle of SMPS
The switching regulator is regulated in the switching power supply. A series switching element turns on and off the current supply of a smoothing capacitor. The voltage on the capacitor controls the rotation time of the series element. The continuous switching of the capacitor maintains the voltage at the required level.
Design basis
The AC power supply first passes through the fuse and line filter. Then it is rectified by full wave bridge rectifier. The rectified voltage is next applied to the power factor correction (PFC) pre regulator, followed by the downstream DC-DC converter.
Most computers and small appliances use IEC style input connectors. As for output connectors and pins, except for some industries, such as PC and compact PCI, generally speaking, they are not standardized and are determined by the manufacturer.
Why SMPS
Like all electronic products, switching power supply also includes some active and passive components. Like every gadget, it has its own advantages and disadvantages.
Let's start with why you should choose SMPS
Switching action means that the series regulator element is on or off. We can achieve a very high level of efficiency by consuming as little energy as heat. Due to high efficiency and low heat dissipation level, switching power supply can be compact. Switching power supply technology can also provide efficient voltage conversion in step-up or step-up applications, step-down or step-down applications.
Transient spikes due to switching action, if not properly filtered, will migrate to other areas of the circuit. These can cause electromagnetic or radio frequency interference and affect other nearby electronic equipment, especially when they receive radio signals.
It may be difficult to ensure that SMPS is implemented according to the required specifications, especially ripple and interference levels.
What will happen in the future?
In the future, we can have more efficient switching power supply. The goal is a better converter to do the most effective conversion process. The designer's key areas in improving SMP efficiency are:
Higher output power
High current output and low voltage
Increased power density
Switching devices such as Schottky diodes are used
