Switching Power Supply Transformer

Switching power supply transformer

Switching power supply transformer is joined the switch tube power transformer, in addition to the ordinary transformer voltage transform function in the circuit, also both insulation isolation and power transfer function commonly used in switching power supply on the occasion of high frequency circuit.role

Switching power supply transformer and switch tube together form a self-excited blocking oscillator (or he) type, thus the input dc voltage from a high frequency pulse voltage.

Energy transfer and conversion effect. In the flyback type circuit, when the switch tube conduction, transformer converts electrical energy into magnetic field can be stored, when the switch pipe cut-off is released. In normal shock type circuit, when the switch tube conduction, the input voltage supply directly to the load, and the energy stored in the energy storage inductors. When the switch pipe cut-off, then continue to load transfer shall be conducted by energy storage inductors.

The input dc voltage into all kinds of low pressure.classification

Switch power supply transformer single and double shock excitation type switching power supply transformer switch power transformers, the working principle and structure of the two kinds of switching power supply transformer is not the same. Single IP switch power transformer is the input voltage of single pulse, and it also points and excitation voltage output; And double cream type switching power supply transformer input voltage is bipolar pulse, general is bipolar pulse voltage output.

Characteristic parametersVoltage ratio: refers to the primary voltage of the transformer and the ratio of secondary voltage.

Dc resistance: copper resistance.

Efficiency: the output/input power * 100 [%]

Insulation resistance: between transformer's winding and the insulation between the core ability.

The electric strength: transformer within 1 second or 1 minute can withstand the prescribed voltage levels.

compositionThe main material of switch power supply transformer, magnetic material, conductor material and insulation material is the core of switching transformer.

Magnetic materials: switch transformer used for soft magnetic ferrite magnetic materials, according to its composition and application of frequency can be divided into two categories, and NiZn MnZn department. The former has a high permeability and high saturation magnetic induction, the intermediate frequency and low frequency range with low loss. The shape of the magnetic core, such as EI type, type E, EC type, etc

Skeleton materials: switch transformer skeleton is different from general transformer skeleton, as well as the coil insulation and support materials, also undertake the installation of the transformer fixed and positioning, so make a skeleton materials in addition to meet the requirements of insulation, shall also have the considerable tensile strength, at the same time in order to inherit the pin welding heat resistant, skeleton material thermal deformation temperature higher than 200 ℃, the material must meet flame retardant, and should also be good processability, easy processing into various shapes.

Detection method

1, by looking at the appearance of transformer to check whether they have obvious anomaly. Fracture, such as whether the coil wire welding, insulation material whether have sear, core fastening screw loosening, silicon steel sheet of rustily, winding coil to see if there is leakage, etc.

2, insulation test. With multimeter R x 10 k measuring core and primary, respectively, and the secondary, primary and secondary, core electrostatic shielding layer and the hem between the secondary and secondary winding resistance, multimeter pointer position should be refers to the infinite. Otherwise, the transformer insulation performance.

3, coil on and off. Puts a multimeter R x 1 block, tests, if a winding resistance to infinity, explain the winding is open circuit fault.

4, the primary and secondary coil discriminant. Power transformer and secondary primary pin pin are generally from the sides, respectively, and primary winding, marked 220 v secondary windings are rated voltage value, such as 15 v, 24 v, 35 v. According to these marks for identification.