| 摘要 |
1,090,047. Electric selective signalling. FAIRCHILD CAMERA & INSTRUMENT CORPORATION. May 11, 1965 [July 15, 1964], No. 19752/65. Heading G4H. In an integrating analogue-digital converter the ratio of the integrals of an analogue and a reference signal is derived. Upon applying the analogue to the integrator a threshold device gates clock pulses to a counter when the integrator output exceeds the threshold. After a fixed time, the counter reaches full count and the analogue is replaced by the reference which has opposite polarity to the analogue, so that the integrator output returns to zero. When it passes the threshold level the gate is inhibited and the count then shown represents the desired ratio. In the case of large analogue values the counter starts not from zero but from half count. |
