Integrated static switch circuit diagram of the flip-flop TDA1024

The circuit switch S closes when the integrated circuit TDA1024 is activated. A trigger pulse is generated by the zero crossing of the mains voltage, allowing a bidirectional thyristor to conduct full current through the load Rl. When switch S is turned off, no current flows through the load. A varistor is connected in parallel with the triac for protection. The circuit can handle a maximum output power of 1400W with a thyristor BT139, up to 2000W with a thyristor BTW41, and can support output power up to 5000W.

The described circuit utilizes an integrated circuit (IC) TDA1024, which serves as a trigger mechanism for controlling a thyristor-based load. The operation begins with the closure of switch S, which is contingent upon the activation of the TDA1024. The zero crossing of the mains voltage is critical in this design, as it generates a trigger pulse that initiates the conduction phase of the bidirectional thyristor. This allows full current to flow through the load resistor Rl, effectively powering the connected device.

To ensure safe operation, especially during the turn-off phase, the circuit design incorporates a protective varistor in parallel with the triac. This component plays a vital role in suppressing voltage spikes that could potentially damage the thyristor during abrupt changes in load conditions or external disturbances.

The circuit is designed to accommodate various power levels depending on the type of thyristor used. With the BT139 thyristor, the circuit can handle a maximum output power of 1400W. For applications requiring higher power, the BTW41 thyristor can be employed, allowing for an output power of up to 2000W. For even more demanding applications, the circuit can support a thyristor capable of handling up to 5000W, ensuring versatility in various industrial and consumer applications.

The overall schematic design reflects a robust approach to controlling AC loads with precise timing and protection features, making it suitable for a wide range of electrical applications.Circuit switch S is closed after the integrated circuit TDA1024 trigger is turned on. Whenever the zero crossing of the mains voltage generates a trigger pulse, bidirectional thyristor, full current flowing through the load Rl. When the switch S OFF no load current. To protect the Triac in parallel across its varistor. The maximum output power of the circuit is a 1400W, such as the use of thyristor BT139, output power up to 2000W, the use of BTW41, output power up to 5000W.