VIDEO DETECTING CIRCUIT

PURPOSE:To eliminate detection distortion, by leading the input signal of a linear amplifier system to an emitter follower after inversion and amplification and setting the emitter output resistance to 20-100OMEGA, in case that a video is detected with an artificial synchronizing detecting circuit....

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Bibliographic Details
Main Authors USUI AKIRA, FUJIMORI TOSHIMITSU, KUCHIKI TETSUO
Format Patent
LanguageEnglish
Published 15.04.1982
Subjects
BASIC ELECTRONIC CIRCUITRY
DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TOANOTHER
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
PICTORIAL COMMUNICATION, e.g. TELEVISION
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Summary:PURPOSE:To eliminate detection distortion, by leading the input signal of a linear amplifier system to an emitter follower after inversion and amplification and setting the emitter output resistance to 20-100OMEGA, in case that a video is detected with an artificial synchronizing detecting circuit. CONSTITUTION:An input signal is divided into two by buffers 2 and 3 consisting of transistors (TR)Q15 and Q16, and one is applied to a linear inversion amplifier (a) consisting of TRs Q17 and Q18 and resistance R13-R16, and the number of inversion stages is matched to that of a carrier amplifier system 5 to prevent the variance of phase difference due to the degree of modulation, and next, resistances R19 and R20 of TRs Q19 and Q20 of the emitter follower in the next stage are set to 20-100OMEGA, and the phase is delayed with floating capacities C3 and C4 by 9b to eliminate the phase difference between the video carrier generated by the carrier amplifier 5 and the input VIF signal amplifier by a linear amplifier 7, and they are multiplied in 6. By this constitution, a video detection output 8 of a distortionless accurate waveform is obtained.
Bibliography:Application Number: JP19800138559