GB1332671A - Integral honeycomb mounting base for a printing plate - Google Patents

Abstract

1332671 Analog/digital converters GENERAL ELECTRIC CO Ltd 19 April 1971 [4 March 1970] 10399/70 Heading G4H In a balanced multistage coder, for each stage of which one bit of a monophylic coded signal representing the input is derived, the common reference signal for each stage may be varied to alter the gain of the circuit. As described each stage comprises two units as shown in Fig. 2b (except that for the first stage the reference source is excluded). The first receives at its input V = V I - V R and delivers at the X output terminal |2V| when V I is less than V R and at its Y output terminal - |2V| when V I is greater than V R . The second receives at its input - V= - V I + V R and delivers at its X output terminal |2V|, when V I is greater than V R and at its Y output terminal - |2V when V I is less than V R so that by combining the signals at the X output terminals on to a first lead and the signals on the Y output terminals on a second lead output signals |2V| and - |2V| are delivered to the first and second units respectively of the next stage. The reference signal + V R and - V R fed to the two units may be varied to V R (1+D) and -V R (1+D) to vary the gain; the characteristic of each stage being extended regularly and proportionally with the displacement of the reference signal. The system may be used in the P.C.M. transmission of F.D.M. signals since the quantizing noise level in P.C.M. is a function of the quantum step size and independent of the loading, resulting in a degradation of the signal/noise ratio in light loading conditions. By reducing the reference level however the step size is reduced and hence the noise level. The appartus may also be used to accommodate a larger or smaller picture level range in a TV camera. The reference level may be made dependent on the average value of the input. Reference has been directed by the Comptroller to Specification 1,040,614.