AC conversion to DC is called rectification, and DC is converted to alternating current called inverter. The inverter is much more complex than the rectifier. There are two commonly used methods for ac/dc converter
, one is through the SPWM way, modulation of the sine wave waveform (if the square wave can be, this step can be omitted), and then through an H bridge to switch the output voltage polarity, which requires H bridge Switching and SPWM circuit synchronization, technically more complex but the efficiency of this way seems very high, so many inverters are this way.
The use of DC power supply AC equipment is called "inverter" principle is basically the DC power supply for the inverter output transistor, connected to the pipe circuit with the transformer and other components on the tube to form a positive feedback If the need to compare the "strict" current output waveform, but also access to the electronic components, the composition of the output waveform shaping the circuit.
Generally through the diode rectifier circuit or electronic switching circuit, can be converted to direct current AC power. Rectifier circuit, is the frequency AC power into pulsating direct current; Filter circuit, the pulsating DC in the AC component filter to reduce the AC components, increase the DC component; Voltage regulator circuit, the use of negative feedback technology, the DC voltage after rectification to further stability.
1 rectifier - that is, to adjust the exchange of DC, in other words is to make the exchange of positive twisted wave to adjust the X axis above. But now only the pulse. The main components are diodes. Rectification: full-wave rectification (bridge rectifier, with special components or with four diodes), half-wave rectification (x below the wave loss, the current is not continuous. With a diode).
2 filter - adjust the waveform to a smooth DC (available capacitance) Another: according to the required voltage, you can do before the rectification transformer.
AC / DC conversion according to the circuit wiring can be divided into, half-wave circuit, full-wave circuit. According to the power phase can be divided into single, three-phase, multi-phase. According to the circuit quadrant can be divided into a quadrant, two quadrants, three quadrants, four quadrants
AC / DC power control chip
1), the safety isolation: strong electric weak isolation \ IGBT isolation drive \ surge isolation protection \ lightning isolation protection (such as the human body contact with medical electronic equipment isolation protection)
2), noise isolation: (analog circuit and digital circuit isolation, strong and weak signal isolation)
3), ground loop elimination: remote signal transmission \ distributed power supply system
4) protection: short circuit protection, overvoltage protection, undervoltage protection, overcurrent protection, other protection
5) voltage conversion: boost conversion \ buck conversion \ AC / DC conversion (AC / DC, DC / AC) \ polarity conversion (positive and negative polarity conversion, single power supply and positive and negative power conversion, single power supply and multi-power conversion )
6) regulator: AC power supply \ remote DC power supply \ distributed power supply system \ battery
7) Noise reduction: active filtering
AC / DC converter parameter indicators
Including Power efficiency , rated voltage, rated power, pulse current, voltage range, power supply, noise and filter, impedance, maximum discharge current (Imax) power protection, leakage protection, short circuit protection, overcurrent protection, overvoltage protection.