Diacs

Diacs are specialized semiconductor components that play a crucial role in current flow control and triggering thyristors and triacs. Due to their ability to conduct current once a specific breakover voltage is reached, diacs are widely used in automation, power regulation systems, lighting controllers, and pulse circuits.
 

How Do Diacs Work?

A diac is a bidirectional semiconductor device that does not conduct current until its breakover voltage is exceeded. Once this threshold is reached, it becomes conductive, allowing current to flow in both directions. It acts as a switch, enabling smooth voltage and current control in AC circuits.

Key Parameters of Diacs:

✔ Breakover voltage – defines the voltage at which the diac starts conducting (typically between 28V–40V).
✔ Switching current (I_BO) – the minimum current required to maintain conduction.
✔ Low energy losses – no heating effect during switching.
✔ Bidirectional operation – allows current flow in both positive and negative directions.
 

Applications of Diacs

Diacs play a critical role in current and voltage control systems, commonly used in:

• Lighting controllers – used in LED dimmers, halogen lamps, and fluorescent lighting.
• Pulse circuits and voltage generators – applied to trigger thyristors and triacs.
• Power regulation in heating devices – found in boilers, induction heaters, and electric resistors.
• Electric motor control – essential in industrial automation and consumer electronics.
• Protection circuits – used in overvoltage protection and voltage stabilization systems.
   

Types of Diacs

Standard Diacs

✔ Commonly used in power regulators and switching circuits.
✔ Characterized by stable breakover voltage and low power losses.

Programmable Diacs

✔ Allow adjustment of the breakover voltage, providing more flexibility in control circuits.
✔ Used in advanced regulation and voltage stabilization systems.
 

Why Choose Diacs?

✔ High reliability – precise switching in control circuits.
✔ Energy efficiency – minimal power losses during operation.
✔ Bidirectional functionality – ideal for AC voltage applications.
✔ Versatile applications – from consumer electronics to industrial control systems.