Anti-loading CATV interface circuit and method
AssigneeMultiplex Technology, Inc.
InventorJohn B. Crosby
Life of this patent
Estimating the term…
Abstract
A video interface circuit reduces loading losses when a video system component, such as a television receiver, is connected to a transmission line by amplifying the video signal with a high frequency amplifier and providing positive feedback of the amplified signal to the cable.
Claims10
An interface circuit for connecting a video device to a signal tap in a continuous transmission line having one or more electrical conductors without signal splitters for reducing signal losses caused by the video device and compensating for losses in the continuous transmission line without in-line amplification, comprising:
- an amplifier circuit connected to at least one conductor of the continuous transmission line for receiving video signals therefrom and producing an amplified video signal at an amplifier output terminal for delivery to the video device;
- and
- a passive positive feedback circuit connected between the amplifier circuit output terminal and the continuous transmission line for introducing a compensating video signal into the continuous transmission line to compensate for loading causes by the amplifier circuit and the video device so that the interface circuit is transparent to the continuous transmission line.
An interface circuit for connecting a video device to a signal tap in a continuous transmission line without signal splitters and having one or more electrical conductors for reducing signal losses caused by connecting of the video device and compensating for losses in the continuous transmission line without in-line amplification, comprising:
- a first transistor circuit connected to the continuous transmission line for receiving video signals therefrom;
- a second transistor circuit connected between the first transistor circuit and the video device for receiving signals from the first transistor circuit and providing an amplified video signal for delivery to the video device;
- and
- a passive positive feedback circuit connected between the second transistor circuit and the continuous transmission line for introducing a compensating video signal into the continuous transmission line to compensate for loading of the transmission line caused the interface circuit and the video device so that the interface circuit is transparent to the continuous transmission line.
A method for connecting a video device to a signal tap in continuous transmission line without signal splitters and having one or more electrical conductors for reducing signal losses caused by connection of the video device to the continuous transmission line and compensating for losses in the continuous transmission line without in-line amplification, comprising the steps of:
- connecting an amplifier circuit to the continuous transmission line for receiving video signals therefrom;
- producing an amplified video signal at an amplifier output terminal for delivery to the video device;
- and
- connecting a passive positive feedback circuit between the amplifier circuit output terminal and the continuous transmission line for introducing a compensating video signal into the continuous transmission line to compensate for loading causes by the amplifier circuit and the video device so that the interface circuit is transparent to the continuous transmission line.
A method for connecting a video device to a signal tap in a continuous transmission line without signal splitters and having one or more electrical conductors for reducing signal losses caused by connecting of the video device and compensating for losses in the continuous transmission line without in-line amplification, comprising the steps of:
- connecting a first transistor circuit to the continuous transmission line for receiving video signals therefrom;
- connecting a second transistor circuit between the first transistor circuit and the video device for receiving the video signals from the first transistor circuit and producing an amplified video signal for delivery to the video device;
- and
- connecting a passive positive feedback circuit between the second transistor circuit and the continuous transmission line for introducing the amplified video signal into the transmission line.
Dependencies are inferred from the claim text.