GB459853A - Improvements in and relating to television and like systems - Google Patents

Abstract

459,853. Television. WHITE, E. L. C., 32, The Rise, Hillingdon, Middlesex. July 12, 1935, No. 20022. [Class 40 (iii)] Signals, which have been distorted by passing through a channel with a low-frequency cut-off, cause a reactance 5 to assume a charge dependent on the peak amplitudes (synchronizing signal) in the signals, and changes in the charge on the reactance control electric variations which are mixed with the distorted signals to compensate changes in the general tilt of the potential curve of the signals which occur at a sudden change in average brightness, Fig. 1 (not shown). A synchronizing signal overcomes the grid bias due a circuit 3, 17 and causes valves 2, 4 to conduct. When the level of the tips of the pulses change, a charge is given to the condenser 5 which maintains the potential of the cathode of the valve 2 between pulses. Changes in the potential across the condenser 5 cause charging or discharging of a condenser 8 through a valve 6. The potential variations across the condenser 8 are reversed by a valve 9, and fed to an amplifier 12 in parallel with a valve 10, which amplifies the original signals. Since the compensating variations commence only after an interval of one line period, the signals are fed to the valve 10 through a delay network 16. The direct-current component is reinserted as described in Specification 422,906 or 449,242.