Rectifier Application

The main application of the rectifier is to convert AC power to DC power. Since all electronic devices need to use DC, but the power company's power supply is AC, so unless a battery is used, all electronic devices have a rectifier inside the power supply.

As for the voltage conversion of the DC power supply, it is much more complicated. One method of DC-DC conversion is to first convert the power supply to AC (using a device called an inverter), then use a transformer to change the AC voltage, and finally rectify it back to DC power.

Rectifiers are also used in amplitude modulation (AM) radio signal detection. The signal may be amplified (amplify the amplitude of the signal) before detection. If it is not amplified, a diode with a very low voltage drop must be used. When using a rectifier for demodulation, the capacitor and load resistance must be carefully matched. If the capacitance is too small, too much high-frequency components will be transmitted, and too large will suppress the signal.

The rectifier device is also used to provide a fixed polarity voltage required for electric welding. The output current of this circuit sometimes needs to be controlled. At this time, a thyristor (a kind of thyristor) is used to replace the diode in the bridge rectifier, and its voltage output is adjusted by means of a phase control trigger.

Thyristors are also used in various levels of railway locomotive systems to achieve fine-tuning of traction motors. Turn-off thyristors (GTO) can be used to generate AC from a DC power source. For example, this method is used to provide power for three-phase traction motors on Eurostar trains.