| 摘要 |
<p>1,191,078. Control of D.C. motors. ROBERTS MACHINE REBUILDERS Inc. 25 Oct., 1968 [6 June, 1968], No. 50761/68. Heading H2J. [Also in Division G3] Signals representing back e.m.f. across and current through the armature of a motor are derived and used to energize control windings of a magnetic amplifier used to control the energization of the motor armature. The motor field is separately energized (Fig. 1a, not shown). The armature is energized by a bridge rectifier comprising two S.C.R's 24, 26 and two diodes 28, 30. The triggering of the S.C.R's is individually controlled by two primary windings 44, 56 of the magnetic amplifier. The back e.m.f. is applied through filter 40, 42 to control the energization of a first control winding 132. A second control winding 124 is controlled by a set-speed control 126; since both windings 124, 132 are energized through a resistor 117 their energization is interdependent. The armature current responsive signal is derived across an inductance 38 in series with the motor and applied to a third control winding 110 which forms the emitter load of a transistor 100 coupled to a further transistor 120 across the control 126 so that the energization of windings 124, 132 also depends on that of winding 110.</p> |
