Triac Switches are semiconductor devices used in an AC voltage circuit that expands upon a typical thyristor device. Triac Switches comprise two parallel thyristors that are inverted so that their two gate terminals are connected to one another. Unlike a normal thyristor, which can only control a current through half of the cycle, Triac Switches are able to control the current over both parts of the wave in an alternating current. With this design, these switches are able to be activated by both positive and negative charges.

Triac Switches are typically used with heavy, inductive loads, in a wide variety of applications that use AC voltage circuits. These switches are most commonly used for power control in AC systems with higher power switching needs. They are often used to control different lighting fixtures, including lighting dimmer switches. Many small motors and cooling fans in a wide range of different equipment also use Triac Switches. They excel at directly controlling relays and/or starter coils in motors used in AC circuits.

Transistor Switches, on the other hand, operate with a DC voltage circuit. Like Triac Switches, they are intended for use with heavy inductive loads, but they are constructed a bit differently. Transistor Switches are semiconductor devices that use a transistor that has had its base terminal biased differently to turn a DC circuit’s output on or off. When a small current passes through the transistor, it pushes a larger current through the transistor to the control circuit.

Transistor Switches are commonly used in higher power applications than Reed switches. They work well directly controlling relays and/or motors and engines. In addition, they are often found in the microchips of computers and calculators, maps, and in automobiles.

Transistor Switches vs Triac Switches: Which Should You Use?

Transistor Switches and Triac Switches are best suited for applications that need to switch inductive loads or other similar heavy-duty circuits.  While Transistor Switches are designed for use in DC circuits, Triac Switches are designed for use in AC circuits.

Transistor Switches are used in DC circuits and are ideal for applications requiring a more robust switch that can withstand inductive-type loads with high current switching. They have low power loss, while adding the benefit of buffering a typical magnetic reed switch.. Transistor Switches are known for their durability, as they have fewer moving parts and experience less wear over time.

On the other hand, Triac Switches are designed for AC circuits and are particularly effective in controlling inductive loads like motors and lighting systems. The benefits of Triac Switches include their ability to manage current flow in both directions of the AC cycle, making them versatile for controlling AC power. They are also well-suited for high-power applications, such as large motors and lighting systems, offering efficient power regulation that can reduce energy consumption. Triac Switches are also designed to endure heavy-duty applications, having long-lasting performance even in demanding environments.

In summary, if you’re working with heavy-duty DC circuits and want longer life for your switch, Transistor Switches are the right choice. However, for AC power control, especially in applications involving higher power or inductive loads, Triac Switches are the preferred solution.

To learn more about our Triac Switches and Transistor Switches and their applications, contact us.

Either of these designs are available in the following housings:

MLP Housing

Made with rugged glass-filled nylon which works well in harsh environments. Can be built using Reed, Triac or Transistor sub switch design.

Note 1: Some models UL/CSA recognized

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MLT Housing

Uses tough glass-filled nylon material which works well in rugged environments. (Aluminum housing also available as an option.)

Switches can be built using a Reed (AC/DC), Triac (AC) or Transistor (DC) sub switch design.

Note 1: Some models UL/CSA recognized

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MLU Housing

Uses 1/2 inch electrical conduit pipe threads. It’s a good fit for flush mount installations. Can be used as a proximity switch. Can be built with Reed, Triac or Transistor sub switch design.