Abstract: A circuit including an amplifier having an input and an output; and a feedback path comprising a transmission line electrically coupled or electrically connected to the output and the input. A low noise amplifier including the circuit wherein the feedback path cancels noise generated in the low noise amplifier.

Abstract: A front-end circuit suitable for digital multimeters and measurement devices may be configured with strictly capacitive attenuators replacing the resistive attenuators in the AC signal path. An inverting programmable-gain amplifier (PGA) may be built around an operational amplifier (op-amp), with a single resistor for DC feedback providing a 1st-order response for AC coupling. The single resistor may be replaced by a more complex RC network to provide a 2nd-order response. The feedback circuit may also include active components such as additional op-amps, which may assist in shaping the overall response and/or reducing the DC offset at the output of the circuit. The capacitive load presented to the input by the front-end circuit may be minimized to compare to capacitances present in resistive implementations. The circuit would not present a DC load to the input since DC loads are typically the result of a resistive attenuator in the DC signal path.

Abstract: A bipolar regulated power supply employing an autotransformer to couple the output to the load is provided with a direct current feedback connected directly across the load. In this way losses in the transformer and leads connecting to the load are compensated for and direct current is eliminated from the output transformer when the input is ac coupled.

Abstract: An anti-skid brake control system having two wheel velocity pick-up coils connected to respective common mode rejection circuits. A coil open detector including a Norton amplifier is also connected from the said circuits to disable the system controller should an open develop in one of the pick-up coils.