A switching power supply main purpose:
Switching power supply products are widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communications equipment, power equipment, instruments, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, liquid crystal display, LED lamps, communication equipment, audio-visual products, security monitoring, LED light bags, computer chassis, digital products and instruments and other fields.
Two, the main classification of switching power supply:
People in the field of switching power supply technology is the side of the development of related power electronics, the side of the development of switching inverter technology, the two promote each other to promote the switching power supply each year to more than double-digit growth rate toward the direction of the development of light, small, thin, low-noise, high-reliability, anti-interference. Switching power supply can be divided into AC/DC and DC/DC two categories.
Micro low-power switching power supply
Switching power supply is moving towards mass, miniaturization. Switching power supply will gradually replace the transformer in the life of all applications, low-power miniature switching power supply applications to be first reflected in the digital display meter, smart meters, cell phone chargers and so on. At this stage, the country is vigorously promoting the construction of smart grid, the requirements of the power meter greatly increased, switching power supply will gradually replace the transformer in the power meter above the application.
Inverting series switching power supply
The difference between inverting series switching power supply and general series switching power supply is that the output voltage of this inverting series switching power supply is negative voltage, which is exactly opposite to the general positive voltage output of the series switching power supply; and due to the energy-storage inductance L only outputs the current to the load when the switch K is switched off, therefore, under the same conditions, the inverting series switching power supply outputs the current to the load, which is the same as that of the inverting series switching power supply. series switching power supply output current than the series switching power supply output current is twice as small.
Three, switching power supply repair steps:
1, repair switching power supply, first of all, use a multimeter to detect whether the power components of the power supply rectifier bridge stack, switching tubes, high-frequency high-power rectifier; inhibit the inrush current of the high-power resistor is not burned. Then test the output voltage port resistance is abnormal, the above components need to be replaced if damaged.
2, the first step is completed, the power supply can not work properly, then to detect the power factor module (PFC) and pulse width modulation components (PWM), consult the relevant information, familiar with the function of each foot of the PFC and PWM module and its modules work properly necessary conditions.
3, then, for the PFC circuit power supply needs to be measured on both sides of the filter capacitor voltage is 380VDC or so, such as 380VDC or so voltage, indicating that the PFC module is working properly, and then test the PWM components of the working state.
Measurement of its power input VC, reference voltage output VR, start control Vstart/Vcontrol terminal voltage is normal, the use of 220VAC/220VAC isolation transformer to the switching power supply, with an oscilloscope to observe the PWM module CT end of the waveform to the ground is a good linear sawtooth wave or triangle.
If the TL494 CT end is a sawtooth wave, the FA5310 CT end is a triangle wave. Whether the waveform of output V0 is an ordered narrow pulse signal.
The above content is a small introduction to the switching power supply maintenance, switching power supply for electricity is very important, I hope that the content of the editor can help you.