Automatic amplitude level control circuit

Abstract

Abstract PURPOSE:To improve the accuracy of level adjustment by using a composite signal being the sum of a chroma signal and a pseudo synchronizing signal having a DC component. CONSTITUTION:A composite signal C+Hs* being the sum of a chroma signal C and a pseudo synchronizing signal Hs* is branched into two at a point A, one is fed to one input terminal of an AGC detection circuit 7 via a clamp circuit 6 provided to a main line 5. The other receives a 1H delay at a delay element 8 and a gain loss and is sent to other input terminal of the AGC detection circuit 7 via a VCA 10 and a clamp circuit 11. The AGC detection circuit 7 uses a differential amplifier and its output signal is fed as a control signal to the VCA 10 to apply gain control.

Inventors

• 👤 Takao Yoshikawa
• 👤 吉川　孝雄
• 👤 Isao Masuda
• 👤 益田　功

Bibliographic Details