Q4004R4

Thyristors - TRIACs

A TRIAC (Triode for Alternating Current) is a type of thyristor that can conduct in either direction and is used most often for controlling AC signals. The Q4004R4 is a four-quadrant, zero-crossing TRIAC that is used in the control of higher-voltage AC applications.

Q4004R4 Application Field

The Q4004R4 is generally used for light dimming, motor speed control, solenoid and contactor control, and other higher-voltage AC applications. It can handle a peak on-state current of 4 amperes (A) and has an operational voltage range of 2 V up to 600 V AC or 800 V DC. In addition, it has a capacitor turn-off ability, meaning it can be used to switch load currents that contain significant capacitive components.

Q4004R4 Working Principle

The Q4004R4 is a four-quadrant TRIAC, which means that it can conduct in either direction and can be switched on or off at different points in each AC waveform. This makes it possible to control AC waveforms with precision. In operation, the TRIAC can be turned on and off by varying the gate current. When the gate current is high enough, the TRIAC will begin conducting, allowing current to flow from the anode to the cathode. Once the TRIAC is conducting, it will remain on until the current drops below the holding current.

The Q4004R4 also has a zero-crossing capability, which means that it can be switched on and off at zero volts, eliminating the in-phase power surges that are seen when using a typical SCR or diode. This makes the Q4004R4 an excellent choice for applications where power surges need to be suppressed.

Conclusion

The Q4004R4 is a four-quadrant, zero-crossing TRIAC that is well-suited for controlling high-voltage AC applications. It has a peak on-state current of 4 A, an operational voltage range of up to 800 V, a capacitor turn-off capability, and a zero-crossing capability that eliminates in-phase power surges. This makes the Q4004R4 a great choice for applications requiring precise control of AC waveforms.