Line-synchronized-driver

The gate drive that phase controls the four parallel SCRs is achieved using a complementary MOS hex gate MC14572 and two bipolar transistors. This adjustable line-synchronized driver allows SCR conduction from near zero to 180 degrees. A Schmitt trigger clocks a delay monostable multivibrator, which is followed by a pulse-width monostable multivibrator. Line synchronization is accomplished through the half-wave section of the secondary winding of the full-wave, center-tapped transformer. This winding also provides power to the circuit through rectifiers D1 and D2.

The circuit described utilizes a complementary MOS hex gate, specifically the MC14572, in conjunction with bipolar transistors to effectively manage the gate drive for four parallel silicon-controlled rectifiers (SCRs). This configuration enables precise phase control, allowing the SCRs to conduct over a range from near zero degrees to 180 degrees, which is critical for applications requiring controlled power delivery.

The operation begins with a Schmitt trigger that generates a clock signal, which is fed into a delay monostable multivibrator. The purpose of the delay monostable multivibrator is to introduce a controlled delay to the signal, ensuring that the SCRs are activated at the appropriate phase angle. Following this, a pulse-width monostable multivibrator is employed to modulate the width of the output pulse, which directly influences the SCR conduction time.

Synchronization with the AC line voltage is achieved through the half-wave section of the secondary winding of a full-wave, center-tapped transformer. This method of synchronization ensures that the SCRs are triggered in accordance with the AC line frequency, thereby enhancing the efficiency and stability of the power control system.

Additionally, the secondary winding of the transformer not only facilitates line synchronization but also supplies power to the entire circuit. The power is rectified by diodes D1 and D2, which convert the AC voltage from the transformer into a usable DC voltage for the circuit components. This dual functionality of the transformer winding is critical for maintaining the operational integrity of the gate drive system while ensuring that all components receive the necessary power for proper operation.The gate drive that phase controls the four parallel SCRs is accomplished with complementary MOS hex gate MC14572 and two bipolar transistors. This adjustable line-synchronized driver pennits SCR conduction from near zero to 180 degrees. A Schmitt trigger clocks a delay monostable multivibrator that is followed by a pulse-width monostable multivibrator.

Line synchronization is achieved through the half-wave section of the secondary winding of the full-wave, center-tapped transformer. This winding also supplies power to the circuit through rectifiers D 1 and D2. 🔗 External reference