5Pcs RobotDyn? Thyristor AC Switch Relay Module 3.3V/5V Logic AC 220V/5A Peak 10AFeature: If you need to control the AC power (lights, home equipment's), a thyristor is what you need. This is a very common thyristor module with very low on resistance and a control voltage, that is compatible with any 3. 3V or 5V micro controller or mechanical switch. This allows you to control high power devices with very low power control mechanisms. This board has an optoisolator to protect your micro controller from high AC currents. We also