The working principle of DC regulated power supply
Figure 2 rectifier circuit
Figure 3 shows the waveform
In a bridge rectifier circuit, each diode is only conductive in half a cycle, so the average current flowing through each diode is equal to half the average of the output current. Each diode in the circuit receives the maximum reverse voltage (U2 is the transformer secondary voltage RMS). In the design, often use the voltage across the capacitor can not be mutated and the current flowing through the inductor can not be the characteristics of the capacitor and the load capacitor in parallel or capacitor and load resistor in series, in order to achieve the purpose of the output waveform is basically smooth. After selecting the capacitor filter circuit, the DC output voltage: Uo1 = (1.1 ~ 1.2) U2, DC output current: (I2 is the effective value of the secondary side of the transformer.), The regulator circuit can be integrated integrated three-terminal regulator circuit.
DC power supply principle DC power supply is a 220V frequency AC power conversion into a constant voltage output DC voltage device, it needs to transform, rectify, filter, regulator four links to complete, see Figure 1. Figure 1 DC power supply block diagram
Among them: (1) power transformer: is a step-down transformer, it will convert 220V AC voltage to meet the needs of the AC voltage, and sent to the rectifier circuit, the transformer ratio by the transformer secondary voltage to determine. (2) rectifier circuit: the use of one-way conductive components, the 50Hz sinusoidal alternating current into pulsating DC (3) filter circuit: the rectifier circuit output voltage in the majority of the AC component to be filtered, resulting in a relatively smooth DC Voltage. (4) voltage regulator circuit: the function of the regulator circuit is to stabilize the output DC voltage, does not change with the AC grid voltage and load changes. Rectifier circuit often use diode single-phase full-wave rectifier circuit, the circuit shown in Figure 2. In the positive half of u2, the diodes D1, D2 conduction, D3, D4 cut off; u2 negative half weeks, D3, D4 conduction, D1, D2 cut off. Positive and negative half of the internal current flowing through the load resistance RL, and the direction is the same. The output waveform of the circuit is shown in Fig.
DC power supply is a 220V frequency AC power into a voltage regulator output voltage of the DC device, it requires transformer, rectifier, filter, regulator four links to complete.
among them:
(1) power transformer: a step-down transformer, it will convert 220V AC voltage to meet the needs of the AC voltage, and sent to the rectifier circuit, the transformer ratio by the transformer secondary voltage to determine.
(2) rectifier circuit: the use of one-way conductive components, the 50Hz sinusoidal alternating current into pulsating DC.
(3) filter circuit: the rectifier circuit output voltage in the majority of the AC component to be filtered, resulting in a relatively smooth DC voltage.
(4) voltage regulator circuit: the function of the regulator circuit is to stabilize the output DC voltage, does not change with the AC grid voltage and load changes.
Rectifier circuit is often used diode single-phase full-wave rectifier circuit, rectifier bridge. U2 positive half cycle, the diode D1, D2 conduction, D3, D4 cut off; u2 negative half weeks, D3, D4 conduction, D1, D2 cut off. Positive and negative half of the internal current flowing through the load resistance RL, and the direction is the same.
