AC regulated power supply
DC regulated power supply
Inverter regulated power supply
Switching regulated power supply
AC regulated power supply
Also known as AC voltage regulator. With the development of electronic technology, especially electronic computer technology applied to various industrial and scientific research fields, a variety of electronic equipment require stable AC power supply, direct power supply can not meet the needs of the grid, the emergence of AC regulated power supply to solve this problem. Commonly used AC voltage regulator:
① ferromagnetic resonant AC voltage regulator. Composed of saturated choke and the corresponding capacitor, with constant voltage volt-ampere characteristics.
② magnetic amplifier type AC voltage regulator. The magnetic amplifier and autotransformer series connection, the use of electronic circuits to change the impedance of the magnetic amplifier to stabilize the output voltage.
③ Sliding AC voltage regulator. Stabilize the output voltage by changing the position of the sliding contact of the transformer.
④ Induction AC voltage regulator. By changing the phase difference between the secondary and primary voltages of the transformer, the output AC voltage is stabilized.
⑤ thyristor AC voltage regulator. Thyristor as a power adjustment element. High stability, fast response and no noise. But on the communication equipment and electronic equipment to cause interference. 1980s, there are three new AC voltage regulator power supply: compensated AC voltage regulator. Numerical control type and stepping type AC voltage regulator. Purification type AC voltage regulator. Has a good isolation effect, can eliminate the spike interference from the grid.
CNC stabilized power supply: it is through the observation area in the output of the equipment sampling, the current voltage with the rated voltage to make comparisons, check, such as comparing the negative value, then send the data to the central processing unit (CPU), the central processor to make the voltage plus the command. At the same time, the detection area detects whether the semiconductor has been turned on and off. After confirming that there is no error, the central processor makes a voltage plus command to control the semiconductor to work so as to reach the standard of rated voltage. If the positive value, the central processor will make the command of voltage reduction, the whole process of all digital only 0.048 seconds time.
The device stabilizes the instantaneous and repeated voltage changes through a digital control loop to ensure that the output voltage is always the rated voltage.
Digital TAPCHANGING METHOD
Digital TAPCHANGING METHOD
DC VOLTAGE STABILIZER
DC VOLTAGE STABILIZER
DC VOLTAGE STABILIZER
DC VOLTAGE STABILIZER. Its supply voltage is mostly AC voltage, when the AC supply voltage voltage or output load resistance changes, the regulator's direct output voltage can be kept stable. The parameters of the voltage regulator are voltage stability, ripple coefficient and response speed. The former indicates the effect of changes in the input voltage on the output voltage. The ripple coefficient indicates the size of the AC component of the output voltage under rated operating conditions; the latter indicates the time required for the voltage to return to normal when the input voltage or load changes drastically. DC regulated power supply is divided into two categories: continuous conductive and switching. The former by the industrial frequency transformer to single-phase or three-phase AC voltage to the appropriate value, and then rectified, filtered, to obtain an unstable DC power supply, and then by the regulator circuit to obtain a stable voltage (or current). This power line is simple, small ripple, small mutual interference, but the volume is large, more supplies, low efficiency (often less than 40% to 60%). The latter to change the adjustment element (or switch) on-off time ratio to regulate the output voltage, so as to achieve voltage regulation. This type of power supply power consumption, efficiency up to 85% or so, but the disadvantage is that the ripple is large, mutual interference. Therefore, the rapid development since the 80s. From the mode of operation can be divided into:
① Controlled rectifier type. Adjust the output voltage by changing the on-time of the thyristor.
② Chopper type. The input is unstable DC voltage, to change the on-off ratio of the switching circuit to get a unidirectional pulsating DC, and then filtered to get a stable DC voltage.
③ Converter type. Unstable DC voltage first converted into high frequency AC by the inverter, and then by the transformer, rectifier, filtering, from the resulting new DC output voltage sampling, feedback control inverter operating frequency, to achieve the purpose of stabilizing the output DC voltage.
Electrical applications
AC regulated power supplies are used to stabilize and protect computers and their peripheral devices, medical electronics, communication and broadcasting equipment, industrial electronics, automatic production lines and other modern high-tech products. [3] DC regulated power supply is widely used in national defense, scientific research, colleges and universities, laboratories, industrial and mining enterprises, electrolysis, electroplating, charging equipment and other DC power supply.
(1) can be used for a variety of electronic equipment aging, such as PCB aging, home appliances aging, all kinds of IT products aging, CCFL aging, lamp aging
(2) for the need to automatically timed power on and off, automatic cycle number of the electronic components of the aging, testing
(3) Electrolytic capacitor pulse aging
(4) Resistor. Relays, motors, etc. test seasoning
(5) machine seasoning; electronic component performance testing, routine testing
Inverter regulated power supply
The so-called inverter regulated power supply is also known as the inverter power supply, this inverter power supply using a 16-bit Motorola processor control, high-frequency PWM design, the original import of the Mitsubishi 1GBT drive. Efficiency of more than 85%. Fast response, for 100% de-loading/loading, the response time of voltage stabilization is within 2ms. The frequency conversion power supply overload capacity, instantaneous current can withstand 300% of the rated current. Pure waveform, high and stable frequency, no interference magnetic wave (EMI, EMC). Inverter power supply is not only the best power supply for R&D and laboratory, metrology room, but also the standard power supply for EM/EMC/safety test.
◇This inverter power supply is characterized by strong load adaptability, high efficiency, good stability, good output waveform quality, easy operation, small size and light weight. This frequency conversion power supply is designed for different power supply types around the world, and users can not only simulate their voltages and frequencies (47-63Hz) for testing applications; the medium frequency power supply specially designed in accordance with the national military standard can also support the 400Hz frequency of the national defense and military reconnaissance, avionics and navigation, communication and other application equipment.
◇This frequency conversion power supply can be used normally for a long time regardless of pure resistive, capacitive, inductive or non-linear loads. Three-phase can be used in single-phase. The voltage and frequency can be adjusted with the load. Some of these models can be set up with a power-on password, which is convenient for safe use in production workshops.
Switching regulated power supply
Figure 1 draws the schematic diagram and equivalent principle block diagram of switching regulated power supply, which is composed of full-wave rectifier, switching tube V, excitation signal, renewable diode Vp, energy storage inductance and filter capacitor C. In fact, the core part of the switching regulator power supply is a DC transformer.
The inverter, which is a device that converts DC to AC. Inverters are usually widely used in standby power supplies that are made up of levels or batteries.
A DC converter, which is a device that converts DC to AC and then AC to DC. This device is widely used in switching regulated power supplies. DC converter can be used to convert a DC supply voltage into a variety of DC supply voltage with different polarity and value.
Advantages
[1]. Low power consumption and high efficiency. In the switching regulated power supply circuit in Fig. 1, transistor V is excited by the excitation signal, it alternately works in the switching state of on-off and off-on-off, and the conversion speed is very fast, the frequency is generally about 50kHz, and in some technologically advanced countries, it can be done at several hundred or nearly 1000kHz. this makes the switching Transistor V power consumption is very small, the efficiency of the power supply can be greatly improved, its efficiency can reach 80%.
[2]. Small size and light weight. From the schematic block diagram of the switching regulator power supply, it is clear that no bulky industrial transformer is used here. As the power dissipated on the adjustment tube V is substantially reduced, and then eliminates the need for a larger heat sink. Because of these two reasons, so the switching regulator power supply is small and lightweight.
[3]. Wide range of voltage stabilization. The output voltage from the switching regulated power supply is regulated by the duty cycle of the excitation signal, the change in the input signal voltage can be compensated for by frequency adjustment or widening, so that in the case of a large change in the industrial frequency grid voltage, it is still able to ensure that there is a more stable output voltage. Therefore, the voltage stabilization range of switching power supply is very wide, and the voltage stabilization effect is very good. In addition, there are two methods to change the duty cycle: pulse width modulation type and frequency modulation type. In this way, the switching regulated power supply not only has the advantage of a wide range of voltage regulation, but also more methods to achieve voltage regulation, designers can be flexible according to the requirements of the actual application of various types of switching regulated power supply.
[4]. The efficiency of filtering is greatly improved, so that the capacity and volume of the filter capacitor is greatly reduced. Switching regulated power supply operating frequency is basically working at 50kHz, is a linear regulated power supply 1000 times, which makes the rectified filtering efficiency almost also increased by 1000 times. Is the use of half-wave rectification with capacitor filtering, the efficiency is also increased by 500b times. In the same ripple output voltage, the use of switching regulated power supply, the filter capacitance is only linear regulated power supply filter capacitance of 1/500-1/1000.
[5]. The circuit form is flexible. For example, there are self-excited and other excitation type, there are width-modulated and frequency-modulated type, single-ended and double-ended type, etc., the designer can play the strengths of various types of circuits to design a switching regulated power supply that can meet different applications.
Disadvantages
The disadvantage of switching regulated power supply is the existence of more serious switching interference. Switching regulated power supply, power adjustment switching transistor V work in the state, it produces AC voltage and current through the circuit of other components to produce spike interference and resonance interference, these interferences if you do not take certain measures to inhibit, eliminate and shielding, it will seriously affect the normal operation of the machine. In addition, due to the switching regulated power supply oscillator does not have the isolation of the industrial frequency transformer, these interferences will be strung into the industrial frequency power grid, so that other electronic instruments, equipment and household appliances in the vicinity of the serious interference.
At present, due to the domestic microelectronics technology, capacitive resistance device production technology and magnetic materials technology and some technologically advanced countries still have a gap, so the cost can not be further reduced, but also affects the reliability of the further improvement. So in China's electronic instruments and electromechanical integration instruments, switching regulator power supply can not be very widely popularized and used. Especially for no frequency transformer switching regulated power supply in the high-voltage electrolytic capacitors, high-voltage switching tubes, switching transformer core materials and other devices, in China is still in the research and development stage. In some technologically advanced countries, switching regulated power supply although there is a certain degree of development, but in practical applications there are still some problems, not very satisfactory. This exposes another disadvantage of switching regulated power supply, that is, the circuit structure is complex, high failure rate, maintenance trouble. In this regard, if the designers and manufacturers do not pay full attention, it will directly affect the popularization and application of switching regulated power supply. Today, the main reason why it is difficult to promote the use of switching regulated power supply is that it is difficult to produce technology, maintenance trouble and high cost.