When working with thyristors, a crucial component in power electronics, it is essential to follow certain precautions to ensure reliable operation and avoid potential damage. Whether you're selecting the right device for your circuit or preparing for installation, understanding these precautions can help maintain the longevity and performance of your thyristor. Below, we outline key considerations to keep in mind when working with thyristors, from selecting the appropriate voltage and current ratings to ensuring proper heat dissipation and protection against electrical stresses.

1. Voltage Rating: When selecting the rated voltage of the thyristor, consider the peak voltage under actual working conditions, and ensure a margin of at least 20-30% higher than the expected peak voltage to accommodate voltage spikes and transients.

2. Current Rating: When selecting the rated current of the thyristor, account for the average current passing through the component, the conduction angle (duty cycle), and the heat dissipation and ventilation conditions during normal operation. Additionally, ensure that the shell temperature does not exceed the allowable value for the corresponding current, and consider potential surge currents that may occur.

3. Multimeter Check: Before using the thyristor, use a multimeter's diode test function to check whether the thyristor is in good condition. If a short circuit or open circuit is detected, replace the thyristor immediately.

4. Avoid Megohmmeter Testing: It is strictly forbidden to use a megohmmeter or a shaker to check the insulation of the thyristor, as these devices generate high voltages that can damage the sensitive semiconductor junctions.

5. Heat Dissipation: Thyristors with a current rating of more than 5A should be equipped with a radiator, and specified cooling conditions must be guaranteed. To ensure good thermal contact between the radiator and the thyristor core, apply a thin layer of thermally conductive silicone grease between them. Ensure the heatsink is appropriately sized based on the power dissipation requirements.

6. Overvoltage and Overcurrent Protection: Use overvoltage and overcurrent protection devices as required in the main circuit. This may include snubber circuits for overvoltage protection and fuses or current limiters for overcurrent protection.

7. Gate Protection: Prevent forward overload and reverse breakdown of the thyristor gate. Consider using gate resistors or protection diodes to safeguard the gate from excessive current or reverse voltage.