GB923340A - Speed control system for electrically powered mechanism - Google Patents
Speed control system for electrically powered mechanismInfo
- Publication number
- GB923340A GB923340A GB25339/59A GB2533959A GB923340A GB 923340 A GB923340 A GB 923340A GB 25339/59 A GB25339/59 A GB 25339/59A GB 2533959 A GB2533959 A GB 2533959A GB 923340 A GB923340 A GB 923340A
- Authority
- GB
- United Kingdom
- Prior art keywords
- voltage
- signal
- load
- speed
- phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
- H02P23/16—Controlling the angular speed of one shaft
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
923,340. Automatic speed control. SENECA FALLS MACHINE CO. July 23, 1959, No. 25339/59. Class 38 (4). [Also in Group XXXVI] A circuit for sensing the load on an induction motor has a first input signal derived from the phase-to-ground voltage V 1 , a second input signal (voltage V,) being obtained from a current transformer in the line from which voltage V 1 is derived. Voltages V 2 , V 3 represent the transformed values of V 1 , and the rectifier D i accepts the algebraic sum of V 2 , V 4 to produce voltage V 5 , whilst voltage V 6 is the sum of voltages V 3 , V 4 . Voltage V 7 is then the sum of voltages V 5 , V 6 and has a magnitude directly proportional to the current in phase with the voltage V 1 . The combined action of potentiometer P 1 and capacitors C 1 , C 2 , filter the voltages V 5 , V 6 , and provide a smooth direct voltage V 7 , the potentiometer providing means for balancing V 7 to zero for a particular load. An A.C. tachometer generator supplies a signal Vt whose phase reverses with reversal of the motor shaft. This signal is amplified and has its magnitude limited to a constant value VtL to provide a constant voltage V 9 acting as the carrier input to a ring modulator 20, V 7 being the D.C. input to the same modulator. The output voltage V 8 is thus an A.C. signal with the same phase as V 9 and whose magnitude is proportional to V 7 . In a modification, the voltage V 9 is connected to a demodulator and is compared with a reference voltage to provide a resultant voltage whose magnitude is proportional to V 9 and whose polarity reverses as the phase of V 9 reverses. This resultant voltage operates a polarity-sensitive relay to control the D.C. load signal V 7 , whereby a signal of the correct polarity, in accordance with the direction of rotation of the motor, is provided, Fig. 6 (not shown). The A.C. motor may be the prime mover of a mechanical amplifier with an integrally coupled servomotor and tachometer to provide low-level torque and speed. A speed reference potentiometer provides an A.C. signal to an electronic amplifier which also receives a signal from the tachometer. The amplifier output forces the servomotor and tachometer to reach a no-load speed corresponding to the setting of the potentiometer. By adding a load-responsive signal, the speed may be held constant with changing load, or may be varied in a predetermined manner, Fig. 5 (not shown). The load-responsive circuit may provide a speed boost when the load exceeds a predetermined value so that speed-drop may be corrected for variable loads above any fixed losses. For three-phase systems without an earthed star-point, the voltage V 1 is derived from two phases of the supply through a resistance-capacitance network, Fig. 3b (not shown). Specification 686,650 is referred to.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB25339/59A GB923340A (en) | 1959-07-23 | 1959-07-23 | Speed control system for electrically powered mechanism |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB25339/59A GB923340A (en) | 1959-07-23 | 1959-07-23 | Speed control system for electrically powered mechanism |
Publications (1)
Publication Number | Publication Date |
---|---|
GB923340A true GB923340A (en) | 1963-04-10 |
Family
ID=10226074
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB25339/59A Expired GB923340A (en) | 1959-07-23 | 1959-07-23 | Speed control system for electrically powered mechanism |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB923340A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2196547A1 (en) * | 1972-08-14 | 1974-03-15 | Siemens Ag |
-
1959
- 1959-07-23 GB GB25339/59A patent/GB923340A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2196547A1 (en) * | 1972-08-14 | 1974-03-15 | Siemens Ag |
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