AC Power Supply principle and principle analysis
AC Power Supply has positive and negative electrodes, the potential of the positive pole is high and the potential of the negative electrode is low. When the two electrodes are connected to the circuit, the potential difference between the two electrodes can be maintained at a constant distance between the two electrodes. To the negative current.
Alone, the difference between the level of water can not maintain a steady flow of water, and by means of continuous water pump from low to high to maintain a certain water level difference and the formation of a steady flow. Similarly, the electrostatic field generated by the charge alone can not maintain a steady current, and by means of AC Power Supply, the non-electrostatic effect (referred to as "non-electrostatic force") can be used to make the positive charge from the lower potential Is returned to the positive pole at the higher potential by the inside of the power supply to maintain the potential difference between the two electrodes, thereby forming a constant current. Thus, AC Power Supply is an energy conversion device that converts other forms of energy into electrical energy supply circuits to maintain a steady flow of current.
The non-electrostatic force in AC Power Supply is directed from the negative pole to the positive pole. When AC Power Supply is connected to the external circuit, the current from the positive pole to the negative electrode is formed by the electric field force externally (external circuit). In the power supply (internal circuit), the role of non-static force is the current from the negative to the positive pole, so that the flow of charge to form a closed loop.
When the mains power through the input switch connected AC Power Supply will be converted into the design voltage of the mains voltage, into the pre-regulator circuit, the pre-regulator circuit is the required AC Power Supply for the initial regulation, the purpose is to reduce High power regulator tube input and output between the tube pressure drop, reduce the power consumption of high-power regulator tube to improve the efficiency of AC Power Supply, pre-AC power Supply is generally controlled by the thyristor phase change with the relay switch AC Power Supply The output tap is regulated.
① after the voltage is basically stable, ripple relatively small DC, through the control circuit in the control of the high-power regulator tube to accurately and quickly asked, after the top pressure will be stable and the performance of the standard DC voltage and then pass the standard filter.
② After filtering, we get the required output DC. In order to get the AC power supply or steady current value, we need to sample the output voltage and current value and send it to the control / Protection circuit, control / protection circuit to detect the AC Power Supply value and current value and voltage / current setting circuit to compare the value of the value of the drive after the pre-regulator circuit and high-power regulator to DC AC Power Supply Can output our set voltage and current value, and when the control / protection circuit detects abnormal voltage or current value, etc. will start the protection circuit so that AC Power Supply into the protection state.
The input voltage is constant and the load resistance RL changes the regulation process. When the load resistance RL changes, will cause the corresponding changes in the output current. Since AC Power Supply has a certain internal resistance, AC Power Supply also changes as the output power of the DC power supply changes. AC Power Supply changes the effect of negative feedback, I by BG amplification to provide the required load changes in the amount of load, due to the amplification of BG and BG2, only need AC Power Supply a small amount of change can To meet the load current is very large amount of change. In other words, the load current in a wide range of changes caused by AC Power Supply changes are very small.
It should be noted that this line-adjustable AC Power Supply can only be AC Power Supply approximation, because the adjustment of the negative feedback is maintained by the static error of the AC Power Supply and the reference voltage. If AC Power Supply is absolutely constant, then the adjustment can not be maintained, AC Power Supply will not be able to automatically adjust. So in essence, the regulator circuit is a reference with the value of the feedback control circuit, are poor adjustment system.