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How a Voltage Regulator Works
Time:2022-05-16 Source:Maosheng Electric

The working principle of the voltage stabilizer:

All voltage regulators utilize the same technology to stabilize the output voltage. The output voltage is sampled (Sampled) through a resistor divider (ResistiveDivider) connected to the inverting input terminal (InvertingInput) of the error amplifier (ErrorAmplifier), and the non-inverting input terminal (Non-invertingInput) of the error amplifier is connected to a reference voltage Vref. The reference voltage is generated by the bandgap reference source (BandgapReference) inside the IC. The error amplifier is always trying to force the inputs to be equal across it. For this, it provides load current to keep the output voltage stable:

Vout=Vref(1+R1/R2)

In fact, this type of voltage regulator using a voltage regulator directly is made of the principle of an autotransformer. The AN side in the figure is the input side of the autotransformer, and the BN side is the output side of the autotransformer. If When the input voltage is higher than the output set point of 220V, the autotransformer works in a step-down state, and if the input voltage is lower than 220V, the autotransformer works in a boost state.

This voltage regulator is different from the autotransformer mainly in that the input point A can slide arbitrarily from 0V to 250V. In this way, the input point of the input voltage can be adjusted at any time to meet the constant output voltage. Generally, we put the input side A The point is called the sliding arm, which is driven by the motor through the reduction gear, and the steering of the motor is controlled by the voltage regulator control circuit.

The sampling circuit of the voltage stabilizer monitors the voltage between the two output points of the voltage stabilizer at all times. When the output voltage increases, it controls the motor to move in the direction of the step-down of the autotransformer. When the output voltage reaches the desired voltage, it stops controlling the motor movement. On the contrary, the control circuit controls the motor to rotate in the direction of boosting the autotransformer. It stops when the desired voltage is reached.

The capacity of this type of voltage stabilizer is all borne by the autotransformer of the output voltage transformer, but due to the influence of its manufacturing process, it cannot be made very large, and can only be adapted to low-power occasions. If the power of the regulator is made larger, it is necessary to add a compensation transformer to realize the power expansion of the regulator.

The capacity of this type of voltage stabilizer is all borne by the autotransformer of the output voltage transformer, but due to the influence of its manufacturing process, it cannot be made very large, and can only be adapted to low-power occasions. If the power of the regulator is made larger, it is necessary to add a compensation transformer to realize the power expansion of the regulator

Three-phase voltage regulator works:

The three-phase voltage stabilizer is actually to connect the three voltage stabilizer units together with the "Y" connection method. Then use the control circuit board and the motor drive system to control the voltage regulator transformer to achieve the function of stabilizing the output voltage. If the three regulators The sliding arms of the voltage transformer are all driven by a motor. The voltage regulation method is a unified voltage regulator. If the sliding arms of the three voltage regulating transformers are independently adjusted by three motors, the voltage regulator is a three-phase separate voltage regulator. regulators. They work exactly the same as single-phase regulators.