Thyristor Selection Tips 1. Choosing the Type of Thyristor Thyristors come in various types; the appropriate type should be selected based on the specific requirements of the application circuit.
For AC/DC voltage control, controlled rectification, AC voltage regulation, inverter power supplies, and switching power supply protection circuits, ordinary thyristors can be used.
For AC switches, AC voltage regulation, AC motor linear speed control, lamp linear dimming, and solid-state relays and contactors, bidirectional thyristors should be selected.
For AC motor frequency converters, choppers, inverter power supplies, and various electronic switching circuits, gate turn-off thyristors can be selected.
For sawtooth wave generators, long-duration time delays, overvoltage protectors, and high-power transistor trigger circuits, BTG thyristors can be selected.
For induction cookers, electronic ballasts, ultrasonic circuits, superconducting magnetic energy storage systems, and switching power supplies, reverse-conducting thyristors can be selected.
For applications such as optocouplers, photodetectors, photoal alarms, photocounters, optoelectronic logic circuits, and monitoring circuits in automated production lines, photocontrolled thyristors can be selected.
The selected thyristor should have a certain power margin. Its rated peak voltage and rated current (average on-state current) should both 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 of the thyristor should meet the requirements of the application circuit (referring to the gate control circuit). They should not be too high or too low, otherwise, the normal operation of the thyristor will be affected.
