| 摘要 |
<p>1,246,360. Control of stepping motors. COMMISSARIAT A L'ENERGIE ATOMIQUE. 3 Sept., 1969 [10 Sept., 1968], No. 43651/69. Heading H2J. [Also in Division G3] A programme controller particularly for temperature comprises a potentiometer 1 driven by a motor 2, a device for controlling the speed of the motor at n selectable speeds, a series of reference voltages S1-S3 one of which is supplied through a selector switch 21 to a comparator 9 which also receives an input from potentiometer 1, and a timing device controlled by the comparator capable of energizing one of a number of timing circuits 24. A reference voltage is derived from a low resistance potentiometer Pc, supplied from a stabilized voltage, and the output for the thermocouple 10 are applied in opposition to a heat controller 20. Potentiometer Pc is driven through a reduction unit 7 and clutch 8 by a stepping motor 2 which may be energized by a transistor relaxation oscillator, Fig. 2 (not shown), of which resistor (18) represents one of a number of selectable resistors of different value. Output from a high resistance potentiometer 1 on the same shaft is applied to a comparator 9 together with one of a series of reference voltages S1-S3 selected by a switch 21. The passage of the difference voltage output from comparator 9 through zero initiates operation of timing device 24 which determines the duration of any stage in the programme and also operates switch 21. Each stage may be timed by circuit illustrated in Fig. 3 (not shown) through a relay (16). Two such stages as shown in Fig. 3 may be cascaded the first operating after a period of hours which triggers a second which operates at the end of a period of minutes.</p> |
