The lowest steady-state input voltage that can maintain the output voltage of the converter undetermined.
Soft Line: AC power supply with large impedance. As the load increases, the input voltage to the power supply will drop significantly.
Modern switching power supplies are divided into two types: DC switching power supply and AC switching power supply. The former outputs high-quality direct current, and the latter outputs high-quality alternating current. The core of the switching power supply is the AC-DC converter. The converter is a device that uses power electronics to convert one type of electrical energy into another or multiple forms of electrical energy. According to the type of converted electrical energy, it can be divided into four types: 1. DC a DC converter, which is a converter that converts one DC power into another or a plurality of DC power, is a main component of a DC switching power supply; 2. An inverter is a power exchanger that converts DC power into AC power. It is the main component of the AC switching power supply and the uninterruptible power supply UPS; 3. The rectifier is the electric energy converter that converts the alternating current into the direct current; 4. The crossover is the direct conversion of one frequency of alternating current to another constant frequency. Or variable frequency AC, or a power converter that converts variable frequency AC directly into constant frequency AC. These four types of converters can be either single-row or bidirectional. The unidirectional power converter can only say that the electric energy is input from one direction and converted from the other direction; the bidirectional electric energy converter can realize the bidirectional flow of electric energy.
1. According to whether there is electrical isolation between input and output: non-isolated DC converter with isolated DC converter.
2. Non-isolated DC converters are classified according to the number of active power switching devices: single tube, double tube and four tube.
There are six types of single-tube DC converters, namely, a buck converter, a boost converter, a buck-boost converter, a Cuk converter, a Zeta converter, and a Sepic transform. And so on. Among the six single-tube converters, buck and boost converters are the most basic, and the other four are derived from them.
The dual-tube DC converter has a double-tube series-connected Buck/Boost converter.
Four-tube DC converter such as Full-bridge converter
3. Isolated DC converters can be classified by the number of active power switching devices. There are two types of single tubes: Forward and Flydack.
The double tube has four types of double tube forward, double tube flyback, push pull and half bridge. Four-tube DC converter timely full-bridge DC converter.
The isolated converter can realize the electrical isolation between the input and the output. Usually, the transformer is used for isolation. The transformer itself has the function of voltage transformation, which is beneficial to expand the application range of the converter. The application of the transformer also facilitates the output of multiple voltages.
When the voltage and current rating of the power switch tube are the same, the output power of the converter is usually proportional to the number of switches used, so the output power of the four-tube converter is the largest, and the output power of the single-tube converter is the smallest.
No single converter can be combined with an isolated converter to obtain characteristics that are not available in a single converter.
4. According to the energy transfer, the DC converter has one-way and two-way. The charger with bidirectional function charges the battery when the power is normal. Once the power is interrupted, it can return the battery power to the grid and supply power to the grid for a short period of time. The DC motor control converter is also bidirectional. When the motor is working, the electric energy is transmitted from the power source to the motor, and the motor power is fed back to the power source during braking.
5. DC converters are also divided into self-excited and other controlled. The converter that realizes the self-sustaining periodic switching of the switch by means of the positive feedback signal of the converter itself is called a self-excited converter, and the Loyer converter is a typical push-pull self-excited converter. The switching device control signal in his controlled DC converter is generated by a special control circuit.
Plug or unplug the power supply in a powered system
The peak current flowing into the power supply device when the power is turned on. Since the input filter capacitor is quickly charged, this peak current is much larger than the steady state input current.
The rate of change of the output voltage when the AC input voltage is programmed from the lowest value.
The input power of the power supply unit is directly supplied by the AC power supply. Rectification and Filtering Circuits Previously, 50HZ/60HZ power transformers were not required. This type of power supply is called an off-line power supply.
A diode that isolates one power supply from another during a fault condition.
In order to output a larger current, the outputs of two or more power supplies can be connected together. When operating in parallel, each power supply must have a load sharing function.
PARD: periodic and random offset, usually refers to the power supply output contains 20HZ ~ 20MHZ frequency components.
Post Regulator: Secondary stabilization circuit for the power auxiliary output.
Preload: In order to make the power supply work stably, a load can be preset in the power supply. Usually the current supplied by the power supply to the load is small.
Stiff Line: AC power with low impedance. When the load changes, the input voltage of the power supply device will not change significantly.
Topology: The type of circuit structure of the converter. Common converter circuit structures include flyback, forward, half bridge, full bridge, resonant and zero switching converters.