Its advantages are simple structure, no many components, high reliability, wide voltage range, strong anti-interference and anti-overload capability. Disadvantages are high energy consumption, large noise, bulkiness, and high cost. The parameter regulator developed on the basis of the magnetic saturation principle and the "magnet amplifier-adjustable electronic ac regulator" (ie, Model 614), which has become popular in China in the 1950s, are AC voltage stabilizers of this type. The auto-coupling ratio adjustment type 1 and the mechanical pressure adjustment type use the servo motor to drive the carbon brush to move on the sliding surface of the winding of the autotransformer to change the ratio of Vo to Vi so as to adjust and stabilize the output voltage. This regulator can range from a few hundred watts to several kilowatts. It is characterized by simple structure, low cost, and low distortion of the output waveform; however, due to the electric spark generated by the sliding contact of the carbon brush, the brush is damaged and even burned out and fails; and the voltage adjustment speed is slow. 2, change the tap type, the auto-transformer made of multiple fixed taps, through the relay or SCR (solid state relay) as a switch 10, automatically change the tap position, so as to achieve the output voltage stability. The advantages of this type of regulator are its simple circuit, wide voltage regulation range (130V-280V), high efficiency (â‰¥95%), and low price. The disadvantage is that the regulation accuracy is low (Â±8 to 10%) and the working life is short. It is suitable for the home to supply the air conditioner. High-power compensation type - purification regulator (including precision regulator) It uses compensation to achieve the stability of the output voltage, easy to achieve computer control. Its advantages are good anti-interference performance, high voltage regulation accuracy (â‰¤Â±1%), fast response (40~60ms), simple circuit and reliable operation. Disadvantages are: with computer, program-controlled switches and other non-linear load when the phenomenon of low-frequency oscillation; the input side of the current distortion, source power factor is low; the output voltage has a phase shift on the input voltage. Units that require higher levels of anti-jamming function are suitable for use in cities. When the computer is powered on, it must use about 2-3 times the total power of the computer. Because it has the advantages of stable voltage, anti-interference, fast response and appropriate price, it is widely used. Switching AC regulated power supply It is used in high-frequency pulse width modulation technology. The difference from the general switching power supply is that its output must be the same as the input side with the same frequency and the same phase of AC voltage. Its output voltage waveforms are quasi-square wave, ladder wave, sine wave, etc. The uninterrupted power supply (UPS) on the market draws out the storage power and the charger, which is the voltage regulator of a switching AC power supply. Good performance, strong control functions, easy to implement intelligence, it is a very promising AC power supply. However, because of its complicated circuit and high price, promotion is slow.
2. Type and selection of DC stabilized power supply: DC stabilized power supply can be divided into chemical power supply, linear stable power supply and switching stable power supply.
They also come in a variety of different types: Chemical Power Supplies Our common dry batteries, lead-acid batteries, nickel-cadmium, nickel-metal hydride, and lithium-ion batteries all fall into this category, each with their own advantages and disadvantages. With the development of science and technology, intelligent batteries have been produced. In terms of rechargeable battery materials, U.S. researchers have discovered an iodide of manganese that can be used to make it cheap, compact, long-lasting, and remain after multiple charges. Good environmental friendly rechargeable battery. Linear Power Supply The linear power supply has a common feature in that its power device regulation tube operates in the linear region and stabilizes the output by adjusting the voltage drop between the tubes. Because the static loss of the adjustment tube is large, a large radiator needs to be installed to dissipate heat. Moreover, since the transformer operates at the power frequency (50Hz), the weight is large. The advantages of this type of power supply are high stability, small ripple, high reliability, easy to make multi-channel, and the output is continuously adjustable. The disadvantages are bulky, cumbersome and relatively inefficient. There are many kinds of stable power supply of this kind, from the output nature can be divided into steady voltage power supply and steady current power supply and set steady voltage, stabilize steady flow in steady flow (bistable) power supply. From the output point of view can be divided into fixed-point output power supply, band switch adjustment and potentiometer continuously adjustable several. From the output instructions can be divided into pointer indication type and digital display type and so on. Switching DC stabilized power supply and linear power supply is different from the steady power supply is a switching DC power supply, its circuit types are mainly single-ended flyback, single-ended forward, half-bridge, push-pull and Full bridge type. The fundamental difference between it and the linear power supply is that it does not work at the power frequency but works at tens of kHz to several megahertz. The functional tube is not operating in the saturation and cut-off region, ie the switching state; the switching power supply is thus named. The advantage of switching power supply is small size, light weight, stable and reliable; shortcomings relative to the linear power supply, the ripple is larger (generally â‰¤ 1% VO (PP), good can be more than ten mV (PP) or less) . Its power can be from several watts to several kilowatts. The price is 3 yuan - more than ten thousand yuan / watt.
The following describes several switching power supplies for general custom classification:
1. AC/DC power supply This type of power supply is also called a primary power supply. It takes energy from the power grid and obtains a DC high voltage through high-voltage rectification and filtering. The DC/DC converter obtains one or several stable DC voltages at the output end. Several watts - several kilowatts are products for different occasions. There are many types and specifications of such products. According to the needs of users, the primary power supply (AC220 input, DC48V or 24V output) in the communication power supply also belongs to this category.
2. The DC/DC power supply is also called the secondary power supply in the communication system. It is provided with a DC input voltage by a primary power supply or a DC battery pack, and obtains one or several DC voltages at the output after DC/DC conversion.
3, communication power supply communication power is essentially a DC / DC converter power supply, but it is generally -48V or -24V DC power supply, and backup battery for DC power backup, the DC power supply voltage is converted into the circuit voltage In general, it is divided into central power supply, hierarchical power supply, and single-board power supply. The reliability of the latter is the highest.
4, radio power supply station power input AC220V/110V, output DC13.8V, power is determined by the power supply of the power supply, several security hundreds of security products. In order to prevent the AC power grid from affecting the work of the radio, it is necessary to have a battery pack as a backup. Therefore, in addition to outputting a 13.8 V DC voltage, this type of power supply also has the function of automatically charging the battery.
5, module power With the rapid development of science and technology, the power supply reliability, capacity / volume ratio requirements are getting higher and higher, the module power more and more show its superiority, it has high operating frequency, small size, high reliability, easy to install And combined expansion, so it is increasingly widely used. At present, although the corresponding modules are currently produced in China, the failure rate is higher because the production process fails to catch up with the international level. Although the cost of DC/DC module power supply is high at present, in view of the overall cost of the long application cycle of the product, especially in view of the high maintenance cost and goodwill loss due to system failure, it is still economical to use this power supply module. Cost-effective, it is also worth mentioning here is the Roche converter circuit, its outstanding advantages are simple circuit structure, high efficiency and output voltage, current ripple value is close to zero.
6, special power supply, high voltage, low current power supply, high current power supply, 400Hz input AC / DC power supply, etc., can be attributed to this type, can be selected according to special needs. The price of switching power supply is generally 2-8 yuan / watt special low power and high power supply prices slightly higher, up to 11-13 yuan / watt.
1. The classification and characteristics of AC regulated power supply: It can provide a stable voltage and frequency power supply called AC stable power supply. At present, the majority of domestic manufacturers do work on AC voltage stability. The following describes the classification features of the AC voltage regulators in the market. Parameter adjustment (resonance) type of this type of regulated power supply, the basic principle of voltage regulation is the LC series resonance, and the early appearance of the magnetic saturation regulator belongs to this category.