Clamping device

Abstract

Abstract PURPOSE:To secure a constant pedestal potential, by feeding the potential of the pedestal part which is detected out of the output obtained through the keyed clamping of the synchronous tip part of the video signal back to the reference position of the keyed clamping through the error amplifier. CONSTITUTION:The input video signal A is received by the buffer amplifier 1, and the synchronous signal B is extracted at the synchronous isolating circuit 4. And the clamping pulse C of the synchronous tip and the sample pulse D of the pedestal are generated from the pulse generating circuit 5. Then the output video signal is clamped at the synchronous tip clamping circuit 2 to be delivered via the amplifier 3. This output is supplied to the trap circuit 8 to eliminate the subcarrier. Then the pedestal potential E is detected to be fed back in the form of the reference potential of the synchronous tip clamping.

Inventors

• 👤 Hideki Takimoto

Bibliographic Details