Video signal peaking control system with provision for automatic and manual control

Apparatus for automatically and manually controlling the high frequency peaking content of a video signal, comprising:

• peaking means responsive to said video signal for generating an output peaking component, said peaking means providing controllable amount of said output peaking component in response to a control voltage;
• means for combining said video signal with said peaking component to produce a peaked video signal;
• charge storage means;
• control means with an input for receiving said video signal and an output coupled to said peaking means, said control means being constructed in an integrated circuit and coupled to an external terminal of said integrated circuit, said control means comprising
• an amplifier with an input for receiving said video signal, and an output;
• a detector with an input for receiving output signals from said amplifier and an output coupled to said charge storage means for producing a control voltage representative of the magnitude of output signals from said amplifier;
• and
• means for coupling said control voltage to said peaking means for controlling the magnitude of said peaking component and thereby controlling the peaking content of said peaked video signal;
• filter means coupled to said amplifier for shaping the frequency response of said amplifier such that, in an automatic peaking control mode, said control voltage is a function of video signal high frequency components within a given frequency range;
• and
• manually adjustable peaking control means coupled to said amplifier for controlling the conduction of said amplifier such that, in a manual peaking control mode, said control voltage is a function of the setting of said manually adjustable peaking control means;
• and wherein
• said filter means and said manually adjustable peaking control means are situated external to said integrated circuit and are coupled to said integrated circuit via said external terminal of said integrated circuit.

Apparatus for generating a D.C. control signal for controlling the operation of an electrical circuit, said apparatus comprising:

• frequency selective direct current coupled amplifier means for amplifying a predetermined frequency component of an input alternating current signal;
• means for detecting the magnitude of amplified frequency components from said amplifier means to generate said D.C. control signal in accordance with the detected magnitude of said amplified frequency component;
• manually adjustable means for generating a variable D.C. input signal;
• filter means for determining the frequency response of said amplifier means;
• a terminal to which said manually adjustable means and said filter means are connected;
• and
• means connecting said terminal to said direct current coupled amplifier means for coupling said variable D.C. input signal to said detecting means via said amplifier means such that said variable D.C. input signal varies said D.C. control signal substantially without varying the signal gain of said amplifier means.