Triac Output Not Turning Off (Low Load Current)

What does TRIAC-NO-OFF-LOW-CURRENT mean?

The triac output fails to turn off when the load current is too low (below 25mA). In such conditions, the triac may not operate stably. If an inductive load is connected, the surge current during turn-off can keep the phototriac component in the triac active, preventing complete deactivation.

• Load current is below the minimum required operating current for stable triac operation (less than 25mA).
• Inductive loads causing a turn-off surge that sustains activation of the phototriac within the triac module.

Click steps to track your progress.

1. 1

   Connect a resistor in parallel across the load terminals to increase the total current flow to approximately 100mA, thereby ensuring stable triac operation and proper turn-off.

2. 2

   Calculate the resistance value (R) required using the formula: R ≤ (Voltage across the load) ÷ 100mA. For example, for a 100VAC output, a 1kΩ resistor is suitable.