| 摘要 |
1323769 Electric correspondence control systems PICKER CORP 11 Nov 1970 [28 Nov 1969] 53710/70 Heading G1N [Also in Division H5] In a control circuit for an X-ray shutter (see Division H5), in which the motor 122 is mechanically coupled both to the shutter 124 and to the arm of an adjustable resistor 118, the control signal from circuit 105 and the feedback signal from the resistor 118 are fed to, and control the output pulse durations of, respective similar one-chat multi-vibrators 146A and 146B, which are crossconnected to gates 150A and 150B such that repetative signals, corresponding to the difference between the output pulse durations from the two multi-vibrators, are passed to that trigger circuit 154A or 154B that is connected to the multi-vibrator having the higher amplitude input, to drive the motor 122 in the direction appropriate to equalise the two input signals. Detailed transistor circuitry is disclosed Fig.7 (not shown). |
