According to the classification of the connection between the switching tube and the load, the switching power supply can be divided into three types: series, parallel, and transformer-coupled (parallel). Below are the details of these different types.
Here is the content:
Series type
Parallel type
Pulse transformer-coupled (parallel) type
Series type
The basic form of switching power supply is the series-connected switching power supply, which is characterized by the series connection of the switching regulator with the load. Therefore, the withstand voltage requirements of the switching tubes and the current-continuing diodes are low. And the filter capacitor in the switching tube on and off is current, so the filtering performance is good, the ripple coefficient of the output voltage is small. And its requirements for energy storage inductor core cross-sectional area are also smaller. However, it also has disadvantages: there is no isolation transformer between the output DC voltage and the grid voltage. And if the switch tube internal short circuit, the entire input voltage directly to the load, will cause over-voltage or over-current load, damage to components. Therefore, the output side generally needs to add a voltage regulator to protect.
Parallel type
The basic circuit of the parallel type switching regulator is the same as the series circuit because the switching tube is connected in parallel with the load and is called parallel type. In addition, the diode is usually called a pulse rectifier. When the switching tube saturated conduction, the input voltage is added to both ends of the energy storage inductor. At this time, the current in the inductor rises linearly, the diode reverses bias and cuts off, the inductor stores energy, the current required by the load is supplied by the voltage charged on the capacitor some time ago.
When the switching power supply switch tube cutoff, VD conduction, through the inductance of the current linear decline, the induction voltage is left negative right positive, input voltage and inductance on the induction voltage with polarity series, power input voltage and inductance released by the energy at the same time to provide current to the load, and to charge the capacitor.
Similarly, when the dynamic balance is reached, the inductor increases the current flow when the switching tube is saturated and decreases the current flow when the switching tube is cut off, i.e. the energy on the inductor remains a constant amount.
Pulse transformer-coupled (parallel) type
The switching device of transformer-coupled switching power supplies can be a bipolar transistor or a field-effect tube. Here the primary winding of the pulse transformer plays the role of energy storage inductor, the pulse transformer transmits energy through inductive coupling, which can isolate the input side and the regulated output side from each other and realize the case (base plate) without electricity, and also can conveniently get a variety of DC voltages, which brings convenience to the production and maintenance, therefore, most color TVs use transformer-coupled switching power supply.
The high conversion efficiency of switching power supply is a big advantage, and because of the high frequency of it, it uses a small size, light weight transformer. Therefore, switching power supply will be smaller than linear power supply size, weight will be relatively light. At this point, Zhejiang Ximeng Electronic Technology Co., Ltd. can guarantee the needs and quality of customers.
