Abstract: An electronic test instrument in the form of a clamp meter has a non-contact voltage sensing circuit which includes a blade and sensor built into the clamp. The test instrument also has a shaker circuit that produces a tactile vibration in the presence of an AC voltage. The intensity of the vibration is proportional to the level of the AC voltage. A clean power indicator circuit is provided as well. The clean power circuit compares the level of harmonic distortion plus noise to the full signal and activates an LED if the distortion plus noise is within acceptable limits.

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.

Abstract: An electronic test instrument in the form of a clamp meter has a non-contact voltage sensing circuit which includes a blade and sensor built into the clamp. The test instrument also has a shaker circuit that produces a tactile vibration in the presence of an AC voltage. The intensity of the vibration is proportional to the level of the AC voltage. A clean power indicator circuit is provided as well. The clean power circuit compares the level of harmonic distortion plus noise to the full signal and activates an LED if the distortion plus noise is within acceptable limits.

Abstract: A video signal distribution system comprises an interface device and video signal input means for receiving TV signals on broadcast channels connected to the interface device. A plurality of video appliances and a plurality of TV sets may be connected to the interface device such that the television sets are arranged to be remote from the plurality of video appliances. A person using the system has a remote control device that may be actuated to emit signals for selecting channels for viewing and to control the video appliances. Each of the television sets includes a repeater arranged to receive the control signals from the remote control device and form corresponding electrical control signals. The interface device receives the electrical control signals corresponding to a selected TV set and directs electrical control signals to a selected one of the plurality of video appliances to provide video signals to the television sets.

Abstract: An interface device permits installation of a video system by direction broadband RF signals from an outdoors transmission line to an indoors receiver and by providing electrical power from the receiver to the transmission line for the antenna electronics without requiring a hole for passage of a coaxial cable. Power transmission circuitry includes a first inductor mounted adjacent the first side of a window and connected to the first transmission line to receive DC electrical power therefrom. A square wave drive signal is applied to switch apparatus that converts the DC power received by the inductor into time-varying electrical signals that produce a time-varying magnetic field. A second inductor that is part of a resonant circuit mounted adjacent the dielectric layer opposite the first inductor receives the transmitted power via magnetic induction.

Abstract: An interface device permits installation of a video system by directing broadband RF signals from an outdoors transmission line to an indoors receiver and by providing electrical power from the receiver to the transmission line for the antenna electronics without requiring a hole for passage of a coaxial cable. Power transmission circuitry includes a first inductor mounted adjacent the first side of a window and connected to the first transmission line to receive DC electrical power therefrom. A square wave drive signal is applied to switch apparatus that converts the DC power received by the inductor into time-varying electrical signals that produce a time-varying magnetic field. A second inductor mounted adjacent the dielectric layer opposite the first inductor receives the transmitted power via magnetic induction.

Abstract: A system for supplying control signals, DC power and video signals to a plurality of video system components includes a DC signal splitter and an RF signal splitter. The RF signal splitter carries video signal to a multiplicity of components. The DC signal splitter carries DC power and low frequency control signals to the multiplicity of components. Each of the signal paths for the DC power and the control signals includes DC short circuit protection, which prevents the occurrence of a short circuit in one output from causing the entire system to fail.

Abstract: An integrating analog-to-digital converter for converting an input signal having an amplitude representing an analog quantity into a digital signal representing the quantity wherein the input signal may have either a positive or negative polarity and the converter automatically generates the digital signal without regard to such polarity. The converter uses a single circuit for charging and discharging a capacitor such that any errors or offsets occurring upon charging are fully and automatically compensated for during discharging so as to provide for automatic zeroing of offset errors without separate autozeroing circuitry.

Abstract: A circuit for measuring the root-mean-square (RMS) value of an electrical signal. The output may be linear or logarithmic. The circuit uses devices with logarithmic voltage/ current characteristics (usually transistors), and allows the logarithmic devices to be connected directly together without intervening operational amplifiers. In its simplest form, the invention consists of a rectifier circuit, four transistors and a capacitor.

Abstract: An electro-mechanical package is disclosed which includes an LCD and an IC chip mounted on opposite sides of a PC board by common package-retaining means, which includes posts extending through the PC board and a clip member that latches onto the ends of the posts to retain the package in assembled position. The latching action is resilient and permits non-destructive disassembly.

Abstract: An integrating analog-to-digital converter for producing a digital output signal representing the value of an analog input signal which may have either a positive or negative polarity. The converter uses a switching circuit to reverse an integrator capacitor between charge and discharge periods so that the same input-signal-controlled current source can be used to both charge and discharge the capacitor. This results in inherent zero calibration because any offset errors during the charge cycle are cancelled out by equal and opposite offsets during the discharge cycle.

Abstract: A multi-contact rotary switch in which arcuate cam lobes on the planar faces of a rotatable disc-shaped cam rotor selectively engage a plurality of switch elements. Each switch element is attached to one of two switch blocks positioned adjacent to either cam rotor face. Slots in the switch blocks laterally confine the switch elements to preserve their alignment. A raised annular bearing on the cam rotor face maintains the position of the cam rotor relative to the switch blocks. Terminal extensions from the switch elements extend perpendicular to and away from the planar faces of the cam rotor.

Abstract: In a digital test instrument such as a digital ohmmeter for measuring and digitally displaying the resistance of an unknown circuit element, there is included an electrical continuity tester coupled to the input of the digital ohmmeter for instantaneously and digitally indicating electrical continuity. Connection of the electrical continuity tester to the input of the digital ohmmeter is achieved in a manner such as to not overload or otherwise affect the accuracy of the resistance measurement.

Abstract: In a digital test instrument such as a digital ohmmeter for measuring and digitally displaying the resistance of an unknown circuit element, there is included an electrical continuity tester coupled to the input of the digital ohmmeter for instantaneously and digitally indicating electrical continuity. Connection of the electrical continuity tester to the input of the digital ohmmeter is achieved in a manner such as to not overload or otherwise affect the accuracy of the resistance measurement.