| 摘要 |
1,055,054. Synchronous motors. GENERAL ELECTRIC CO. July 12. 1963 [July 30, 1962]. No. 27808/63. Heading H2A. The speed of a synchronous motor used for driving a clock mechanism is stabilized by connecting an additional pickup coil, inductively coupled to a mechanical oscillator system, to the input of the main D.C. energized oscillator circuit. The motor comprises a stator 12 with polepieces 28, 30, constructed to facilitate self-starting of the permanent magnet rotor 10. The stator is wound with a tapped winding com prising a major coil portion 22 connected across the output of transistor 16 in series with battery 18 and a minor coil portion 26 connected, in parallel with pick-up coil 26, to the input of the transistor. In operation the change in flux in the two halves of the stator windings causes the transistor to be alternately switched " on " and " off " and the pulses of power produce a pulsed magnetic field at the polepieces which cause the rotor to commence rotating. The pulse of power in minor coil 26 when the transistor is switched off passes through coil 20 and attracts permanent magnet rotor 46 which is mounted on torsion strip 38 of the mechanical oscillator shown in Fig. 2. Restoration of this rotor 46 to its rest position induces a reverse voltage pulse in coil 20 which switches on transistor 16 causing the cycle to repeat so that the mechanical oscillator effectively regulates the running speed of the motor. The motor may have the oscillator attached to it so that rotation of the motor rotor provides a disturbing force on the oscillator, Fig. 8 (not shown). In this embodiment the oscillator comprises two oppositely poled magnets 140, 141 supported on a shaft mounted in jewelled pivots and biased to a rest position by hair springs 131, 135. The provision of two magnets nullifies the effect of stray magnetic fields and only one magnet 141 influences pick-up coil 143. The frequency of the oscillator may be adjusted by altering the position of screw 144. The pick-up coil is connected in series with the tapped motor field coil in a transistor oscillator circuit. Specification 1,055.053 discloses a motor using an oscillator having the two magnets mounted on a torsion strip.
|
