Hobbies And Interests
Coil Switching and Voltage-Current Curve Behavior
An average SVR consists of thyristors, a transformer and a microprocessor block. The transformer is outfitted with a primary coil and a number of different coils on the secondary side. All but one of the secondary coils are in operation at any single point in time, adjusting the input to a reference voltage. Any drastic change in the input voltage is offset by simply changing the operational secondary coil. Simpler SVRs use electronic components with voltage-current curves that are near-horizontal lines -- meaning that changes in current cause virtually no change in the voltage.
Electronic Control
An automatic servo voltage regulator uses a motor to adjust the number of windings in the transformer's secondary coil until it produces the desired voltage. In an SVR, thyristors, solid-state semiconductor switches, replace the servo motor for secondary coil control. When the SVR senses the need to adjust the output voltage, the thyristor controlling the working coil switches off, while the one for the appropriate coil switches on.
Speed of Response and Feedback
Because thyristors have an accelerated response compared to a mechanical servo motor, an SVR accomplishes the necessary voltage adjustments more quickly. Upon triggering of the thyristor, voltage regulation becomes merely a matter of switching on the right coil. Some SVRs are equipped with a feedback loop, which constantly compares the produced voltage to a reference value. The more allowance given for feedback, the greater the SVR's accuracy; however, it comes at the cost of stability and speed of response.
Overload Protection
Every SVR has limitations. The simplest ones are designed only for voltages that do not exceeding 600 volts. In the case of a current overload, some SVRs shut down completely or adjust the current to a manageable value -- even if this means slightly affecting the voltage. Some SVRs, when fed voltages beyond their controllable range, power down or supply connected appliances with bypass from the mains, resuming normal operation only when conditions return to normal.