DB3 Diac Trigger Diode

The DB3 Diac Trigger Diode is a bidirectional, two-terminal semiconductor device that conducts current in both forward and reverse directions once the applied voltage exceeds its breakover threshold. Unlike a Triac, it has no gate terminal to control triggering, instead switching on naturally once voltage crosses that breakover point.

With a breakover voltage of 32V and a total power dissipation rating of 150mW, the DB3 is commonly used as a trigger device in phase control circuits, motor speed controllers, light dimmers, and heat control systems. Once triggered, it remains conducting until the current drops below its holding current threshold, making it a reliable component for switching devices, rectifier circuits, and short-circuit protection applications.

• Bidirectional diac design – conducts in both directions once triggered
• 32V breakover voltage – reliable, predictable triggering point
• 150mW power dissipation – suited to low-power trigger circuits
• No gate terminal needed – simple two-terminal operation
• Common applications – light dimmers, motor speed control, heat controls
• Reliable switching behaviour – sharp conduction once breakover is reached

Add reliable triggering to your phase control circuit with the DB3 Diac Trigger Diode.