| 摘要 |
1,263,540. Automatic speed control. QUICKROTAN BECKER & NOTZ K.G. June 18, 1969 [July 19, 1968], No.30886/69. Heading G3R. The speed of a shaft is controlled by alternately energizing a clutch coupling the shaft to a motor and a brake acting on the shaft, the speed of the shaft being measured by an A.C. tachogenerator I whose output is converted to a D.C. with ripple signal, and the clutch and brake being emergized respectively when the D.C. signal falls below or rises above pre-set reference voltages. The tachogenerator comprises a magnetic pulse generator 1 Fig. 2 (not shown) whose output is supplied to a transformer 10 which feeds a rectifier 15 and low pass filter 20, 21 to provide the D.C. signal. The transformer coupling is variable by a pedal 14 to set the speed. The output of the rectifier is biased, by potential divider 17, 18, for rapid response. The output of the filter is fed to a buffer amplifier 24 and a phase inverter 32; output from each are fed respectively to transistor pairs 40, 41 and 34, 35 supplying the coils 2, 3 of the clutch and brake respectively. The pre-set voltage levels are set by potentiometers 29, 33. Coupled to the speed setting pedal 14 is a switch 27 arranged to cause full energization of the brake when the pedal is released for a time dependent on the time constant of capacitor 30. |
