Selection Techniques for Thyristors

Selection Techniques for Thyristors

1. Choose the type of thyristor. There are multiple types of thyristors, and they should be selected reasonably according to the specific requirements of the application circuit.

If used for AC/DC voltage control, controllable rectification, AC voltage regulation, inverter power supply, switch mode power supply protection circuit, ordinary thyristors can be selected.

If used in circuits such as AC switches, AC voltage regulation, linear speed regulation of AC motors, linear dimming of lamps, solid-state relays, and solid-state contactors, bidirectional thyristors should be selected.

If used for AC motor variable frequency speed regulation, chopper, inverter power supply, and various electronic switch circuits, gate turn off thyristor can be selected.

If used for sawtooth wave generators, long-term delay devices, overvoltage protectors, and high-power transistor trigger circuits, BTG thyristors can be selected.

If used in circuits such as induction cookers, electronic ballasts, ultrasonic circuits, superconducting magnetic energy storage systems, and switching power supplies, reverse conducting thyristors can be selected.

If used for optocouplers, photodetectors, light alarms, light counters, optoelectronic logic circuits, and operation monitoring circuits of automatic production lines, light controlled thyristors can be selected.

2. The main parameters for selecting thyristors should be determined according to the specific requirements of the application circuit.

The selected thyristor should have a certain power margin, and its rated peak voltage and rated current (on state average current) should be 1.5 to 2 times higher than the maximum operating voltage and maximum operating current of the controlled circuit.

The forward voltage drop, gate trigger current, and trigger voltage parameters of the thyristor should meet the requirements of the application circuit (referring to the control circuit of the gate), and should not be too high or too low, otherwise it will affect the normal operation of the thyristor.