| 摘要 |
1,048,705. Automatic speed control. PRESNA MECHANIKA, NARODNI PODNIK. May 6, 1965 [May 7, 1964], No. 19120/65. Heading G3R. When change-over switch P4 is adjusted to position 1, a low voltage is applied to the emitter of transistor T1 which is rendered conductive together with the transistor T2, whereby motor M is started. Centrifugal contact P1 opens when the speed reaches a predetermined value, so that the base-potential of the transistor T1 drops. The transistors T1, T2, are rendered non-conductive to include resistor R11 in series with the motor whose speed decreases until contact P1 is reclosed. By repeating this operation the speed of the motor is maintained at a predetermined level. Higher levels of speed are provided by adjusting the switch P4 to the positions 2 and 3. In another arrangement, voltage divider R1-R4 is in the emitter circuit of transistor T1 whilst voltage divider R6-R9 is in the base circuit of that transistor.
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