Abstract A regulating power supply circuit in which the power supplied at the output is controlled by controlling the firing angle of a thyrister switching device in response to changes in a hybrid signal which is indicative of the difference between the RMS value of the output voltage and a desired RMS value. The hybrid signal is formed by summing a feedback current proportional to the absolute load voltage with a reference current proportional to the firing angle of the thyrister on a summing capacitor. Since for any given RMS voltage, the value of the average load voltage varies linearly with the conduction angle over a large range of conduction angles, the phase angle proportional reference current source is utilized to relate the absolute output voltage with the RMS voltage linearly over a wide range of input voltages.
A root mean square voltage regulator for controlling in each half cycle the output voltage supplied to a load from an alternating current supply, said regulator comprising: switching means switchable from a high impedance condition to a low impedance condition in each half cycle connected between said load and said alternating current supply; said switching means having at least one control element for switching said switching means to said low impedance condition when a control signal supplied to the control element exceeds a predetermined threshold level; a feedback circuit connected in circuit with said switching means and said load for supplying a first signal indicative of the absolute value of the output voltage; circuit means coupled with said switching means for supplying a second signal indicative of the duration within each half cycle of the low impedance condition of said switching means; a constant signal source for supplying a constant signal; summing means for combining at least portions of said first signal, said second signal, and said constant signal for synthesizing a hybrid signal indicative of the difference between the root mean square value of the output voltage signal and a desired root mean square value; and means coupled with said summing means and said control element for supplying said control signal as a function of said hybrid signal thereby to maiNtain the root mean square magnitude of the output voltage substantially at a preselected level.
Claim 2
Dependent Claim
236 words
A root mean square voltage regulator for controlling in each half cycle the output voltage supplied to a load from an alternating current supply, said regulator comprising: switching means switchable from a high impedance condition to a low impedance condition in each half cycle connected between said load and said alternating current supply; said switching means having at least one control element for switching said switching means to said low impedance condition when a control signal supplied to the control element exceeds a predetermined threshold level; a feedback circuit connected in circuit with said switching means and said load for supplying a first signal indicative of the absolute value of the output voltage; circuit means coupled with said switching means for supplying a second signal indicative of the duration within each half cycle of the low impedance condition of said switching means; a constant signal source for supplying a constant signal; summing means for combining at least portions of said first signal, said second signal, and said constant signal for synthesizing a hybrid signal indicative of the difference between the root mean square value of the output voltage signal and a desired root mean square value; and means coupled with said summing means and said control element for supplying said control signal as a function of said hybrid signal thereby to maiNtain the root mean square magnitude of the output voltage substantially at a preselected level.
Claim 3
Dependent Claim
33 words
The root mean square voltage regulator set forth in claim 1 wherein said feedback circuit includes rectifying means connected in circuit with said switching means and said load for supplying said first signal.
Claim 4
Dependent Claim
33 words
The root mean square voltage regulator set forth in claim 1 wherein said first signal, said second signal, and said constant signal being current signals and wherein said summing means comprises a capacitor.