High-voltage-regulator
The regulator provides a 100 V output at 100 mA and can withstand shorts to ground. Even at a 100 V output, the LT317A operates in normal mode, maintaining a 1.2 V difference between its output and adjustment pin. Under these conditions, the 30 V zener diode is inactive, allowing Q1 to conduct. When a short circuit occurs at the output, the zener diode becomes active, driving Q1's base to 30 V. This results in Q1's emitter clamping to 2 V below Vz, which is well within the voltage and output rating of the regulator. Additionally, under these circumstances, Q1, a high-voltage component, endures a collector-emitter voltage (VCE) of 90 V at the saturation current specified by the transformer, which is 130 mA, while Q1 safely dissipates 12 W. If Q1 and the LT317A are thermally coupled, the regulator will eventually enter thermal shutdown, leading to oscillation. This protective mechanism will continue as long as the output remains shorted. The 500 pF capacitor and the 100/0.02 µF damper enhance transient response, while the diodes ensure safe discharge paths for the capacitors.
The described regulator circuit is designed to deliver a stable output voltage of 100 V at a current of 100 mA, making it suitable for applications requiring high voltage regulation. The LT317A voltage regulator is central to this design, ensuring that the output voltage remains consistent despite variations in load or input voltage. A key feature of this circuit is its ability to handle short circuits. When a short circuit occurs at the output, the 30 V zener diode activates, which serves to protect the circuit by controlling the base voltage of transistor Q1.
Transistor Q1 plays a critical role in managing the output current during fault conditions. By clamping its emitter voltage to 2 V below the zener voltage, it prevents excessive current from damaging the regulator. The thermal management of Q1 is crucial, as it is capable of sustaining a significant collector-emitter voltage (90 V) while dissipating up to 12 W of power. This is particularly important in high-voltage applications where thermal runaway could lead to failure.
The thermal coupling of Q1 with the LT317A ensures that if Q1 reaches a critical temperature, the regulator will enter thermal shutdown, effectively protecting both the regulator and the load from damage. The transient response of the circuit is enhanced by the inclusion of a 500 pF capacitor and a 100/0.02 µF damper capacitor, which work together to stabilize the output voltage during sudden load changes. Additionally, the diodes in the circuit provide necessary discharge paths for the capacitors, further ensuring the reliability and stability of the output voltage under dynamic conditions.
Overall, this regulator circuit is designed with multiple layers of protection and stability features, making it robust for high-voltage applications while ensuring safe operation even in adverse conditions.The regulator delivers 100-V at 100 mA and withstands shorts to ground. Even at 100 V output, the LT317A functions in the normal mode, maintaining 1.2 V between its output and adjustment pin. Under these conditions, the 30-V zener is off and Ql conducts. When an output short occurs, the zener conducts, forcing Q1"s base to 30 V. This causes Q1"s emitter to clamp 2 VnEs below Vz. well within the V.w VouT rating of the regulator. Under these conditions, Q1, a high-voltage device, sustains 90 V-VcE at whatever current the transformer specified saturates at 130 mA, while Q1 safely dissipates 12 W. If Q1 and the LT317 A are thermally coupled, the regulator will soon go into thermal shutdown and oscillation will commence.
This action will continue, protecting the load and the regulator as long as the output remains shorted. The 500-pF capacitor and the 10 0/0.02 11F damper aid transient response and the diodes provide safe discharge paths for the capacitors.
The described regulator circuit is designed to deliver a stable output voltage of 100 V at a current of 100 mA, making it suitable for applications requiring high voltage regulation. The LT317A voltage regulator is central to this design, ensuring that the output voltage remains consistent despite variations in load or input voltage. A key feature of this circuit is its ability to handle short circuits. When a short circuit occurs at the output, the 30 V zener diode activates, which serves to protect the circuit by controlling the base voltage of transistor Q1.
Transistor Q1 plays a critical role in managing the output current during fault conditions. By clamping its emitter voltage to 2 V below the zener voltage, it prevents excessive current from damaging the regulator. The thermal management of Q1 is crucial, as it is capable of sustaining a significant collector-emitter voltage (90 V) while dissipating up to 12 W of power. This is particularly important in high-voltage applications where thermal runaway could lead to failure.
The thermal coupling of Q1 with the LT317A ensures that if Q1 reaches a critical temperature, the regulator will enter thermal shutdown, effectively protecting both the regulator and the load from damage. The transient response of the circuit is enhanced by the inclusion of a 500 pF capacitor and a 100/0.02 µF damper capacitor, which work together to stabilize the output voltage during sudden load changes. Additionally, the diodes in the circuit provide necessary discharge paths for the capacitors, further ensuring the reliability and stability of the output voltage under dynamic conditions.
Overall, this regulator circuit is designed with multiple layers of protection and stability features, making it robust for high-voltage applications while ensuring safe operation even in adverse conditions.The regulator delivers 100-V at 100 mA and withstands shorts to ground. Even at 100 V output, the LT317A functions in the normal mode, maintaining 1.2 V between its output and adjustment pin. Under these conditions, the 30-V zener is off and Ql conducts. When an output short occurs, the zener conducts, forcing Q1"s base to 30 V. This causes Q1"s emitter to clamp 2 VnEs below Vz. well within the V.w VouT rating of the regulator. Under these conditions, Q1, a high-voltage device, sustains 90 V-VcE at whatever current the transformer specified saturates at 130 mA, while Q1 safely dissipates 12 W. If Q1 and the LT317 A are thermally coupled, the regulator will soon go into thermal shutdown and oscillation will commence.
This action will continue, protecting the load and the regulator as long as the output remains shorted. The 500-pF capacitor and the 10 0/0.02 11F damper aid transient response and the diodes provide safe discharge paths for the capacitors.