Thyristors - TRIACs

A thyristor is an electronic component that includes a switch and a controlling logic circuit. A TRIAC is one type of thyristor. They are used in a variety of applications where the need for fast switching action is desired. One example are industrial motor control, where some types of motors require the use of a TRIAC for fast switching and precise control.

Q4008LH4TP Application Field

The Q4008LH4TP is an example of a Thyristor TRIAC. This component is primarily used in applications where a need for fast, precise switching action is required. This type of component is used in a wide range of applications such as motor starters, heating equipment, AC power supplies, and appliance control.

The Q4008LH4TP has a rated current of 4A, so it is suitable for high current applications, such as motors or heating elements. It has a minimum breakover voltage of 400V to ensure reliable performance in higher voltage applications. The low gate sensitivity of the component makes it suitable for use in high noise environments.

Q4008LH4TP Working Principle

The Q4008LH4TP has three main pins: Gate, Anode and Cathode. When a positive voltage is applied to the Gate pin, a positive current flows through the Anode and Cathode pins. This current flows until the voltage of the Anode and Cathode pins reaches the breakover voltage of 400V. At this point, the device enters a breakdown and begins to switch on.

The device has a low gate sensitivity, which means it requires a lower voltage than usual to transition from the open to the closed state. The low gate sensitivity also makes it suitable for use in high noise environments, as it is less likely to be affected by noise. The device also has a wide range of operating temperatures, making it suitable for use in both cold and hot climates.

Once the device has switched on, it remains in the on state until the voltage of the Anode and Cathode pin drops below the minimum breakover voltage. This is known as the hold current and is directly proportional to the current flowing through the pins. The device will automatically turn off once this set voltage is reached.

Conclusion

The Q4008LH4TP is an example of a Thyristor TRIAC that is suitable for a variety of applications where a need for fast, precise switching action is desired. The device has a rated current of 4A, a minimum breakover voltage of 400V, and a low gate sensitivity, making it suitable for use in high noise environments. The device also has a wide range of operating temperatures, making it suitable for use in both cold and hot climates.