| 摘要 |
<p>1,074,336. Electric selective signalling. DEMAG-ZUG G.m.b.H. April 15, 1965 [July 25, 1964], No. 16360/65. Heading G4H. In a control device, a control signal is derived from the difference between desired and actual value inputs, each represented by a plurality of two-state signals, these latter signals being connectable to " forward " and " reverse " outputs by gate circuits such that the " reverse " output does not receive 1 actual value signals corresponding to a numerical value less than or equal to the desired value and the " forward " output does not receive 1 desired value signals corresponding to a numerical value less than or equal to the actual value. In a feedback positioning system, each decimal digit of the actual and desired values is represented by energizing one out of ten lines, corresponding lines being connected to respective units (such as 1-9, Fig. 1, not shown), each unit being composed of inverters and diode OR-gates as shown in Fig.4 (not shown). The units are connected together so that those between the energized desired and actual value input lines in a given decimal order each produce a voltage output on the same one of two output lines, depending on which input is greater (or on neither if they are equal). These two output lines from each decimal order control the " forward " and " reverse " outputs via logic circuitry (Fig. 2, not shown) which ensures that the higher orders override the lower in deciding the direction of the positioning motor. The motor is slowed when the end point is approached by an arrangement of Schmitt triggers (ST 1 , ST 2 , ST 3 , Fig. 1, not shown), and gates (Fig. 3, not shown), the Schmitt triggers receiving voltages proportional to the number of units producing a voltage output (see above) in respective decimal orders.</p> |
