Switching power supply transformer function
The switching power supply transformer is a power transformer with a switching tube added. In the circuit, in addition to the voltage conversion function of an ordinary transformer, the switching power supply transformer also has the functions of insulation isolation and power transmission. Switching power supply transformers are generally used in switching power supplies and other situations involving high-frequency circuits.
The role of switching power supply transformer
The switching power supply transformer and the switching tube together form a self-excited (or separately excited) intermittent oscillator, thereby modulating the input DC voltage into a high-frequency pulse voltage.
It plays the role of energy transfer and conversion. In the flyback circuit, when the switch tube is turned on, the transformer converts the electrical energy into magnetic field energy and stores it, and releases it when the switch tube is turned off. In the forward circuit, when the switch tube is turned off, When the switching tube is turned on, the input voltage is directly supplied to the load and the energy is stored in the energy storage inductor. When the switching tube is turned off, the energy storage inductor carries out freewheeling and transfers it to the load.
Convert the input DC voltage into various low voltages required.
Classification of switching power supply transformers
Switching power supply transformers are divided into single-excitation switching power supply transformers and double-excitation switching power supply transformers. The working principles and structures of the two switching power supply transformers are not the same. The input voltage of a single-excited switching power supply transformer is a unipolar pulse, and it also has a forward and flyback voltage output; while the input voltage of a double-excited switching power supply transformer is a bipolar pulse, usually a bipolar pulse voltage output.
Characteristic parameters of switching power supply transformer
Voltage ratio: refers to the ratio of the primary voltage to the secondary voltage of the transformer.
DC resistance: copper resistance.
Efficiency: that is, output power/input power*100[%]
Insulation resistance: the insulation ability between the windings of the transformer and between the cores.
Electrical strength: The degree to which the transformer can withstand the specified voltage within 1 second or 1 minute.
