GB582744A - Thermionic impulse amplifier - Google Patents

Abstract

582,744. Pulse amplifying circuits ; television. FARNSWORTH TELEVISION & RADIO CORPORATION. May 10, 1944, No. 8929. Convention date, March 18, 1943. [Classes 40 (iii) and 40 (v)] In a pulse amplifier or synchronizing separator circuit, a first valve is fed over an impedance from a storage device in the output circuit of a second valve, a control voltage for the second valve being developed across the impedance, an amplified pulse or synchronizing signal appearing in the output of the second valve. Valve 3, fed with anode current from a large condenser 15 over resistance 16, is supplied with negative pulses on the grid which reduce the anode current and allow valve 8 to conduct, producing amplified pulses across the integrating circuit comprising resistance 12 and condenser 15. Condenser 15, charged by the pulses through valve 8, maintains the anode current of valve 3 during the period between pulses, the potential difference across resistance 16 biassing valve 8 beyond cut-off. Condensers 7 and 10 decouple the screens of the valves to their cathodes. The input may be a television signal, the video component being of insufficient amplitude to cause valve 8 to conduct, the synchronizing signal alone being effective to produce a signal in the output.