Abstract: A coupling circuit composed of an input terminal for receiving an input signal from a source and first and second output terminals for supplying an output signal to a load; a signal processing device connected between the input terminal and the first output terminal for deriving an output signal from the input signal and for supplying the output signal to a load connected between the output terminals; a power supply; connecting lines each having a finite impedance and connected for supplying operating power from the power supply to the signal processing device, a distortion eliminating circuit connected between the power supply and the second output terminal for directing load current to the signal processing device so as to bypass the load current from the line impedances, the distortion eliminating device including at least one active circuit element and having an electric characteristic corresponding substantially to a capacitor with infinite capacitance.

Abstract: A coupling circuit composed of an input terminal for receiving an input signal from a source and first and second output terminals for supplying an output signal to a load; a signal processing device connected between the input terminal and the first output terminal for deriving an output signal from the input signal and for supplying the output signal to a load connected between the output terminals; a power supply; connecting lines each having a finite impedance and connected for supplying operating power from the power supply to the signal processing device, a distortion eliminating circuit connected between the power supply and the second output terminal for directing load current to the signal processing device so as to bypass the load current from the line impedances, the distortion eliminating device including at least one active circuit element and having an electric characteristic corresponding substantially to a capacitor with infinite capacitance.

Abstract: A circuit for coupling a signal source producing a signal having a given voltage waveform to a load having two ends, the circuit being composed of: a load voltage control unit connectable between the signal source and one end of the load for producing across the load a voltage corresponding to the signal voltage; and a load current control unit connectable to the load and operable independently of the signal source for producing a current flow through the load sufficient to cause the voltage across the load or the current through the load to have the given waveform.

Abstract: An amplifier circuit for applying a voltage from a voltage source across a load having a frequency domain transfer function g(s), the circuit being composed of: a coupling member having a frequency domain transfer function f(s); first connecting elements for connecting the coupling member between the source and the load; a compensating member having a frequency domain transfer function r(s); and second connecting elements for connecting the compensating member to both the source and the load.

Abstract: A battery booster apparatus includes a portable support structure on which are mounted a battery, jumper cables for connecting the battery in parallel with an external battery that is in a low charge condition, an AC-powered charger for charging the battery, and a solar panel for charging the battery when the charger is not powered. The apparatus may include components for switching between the charger and the solar panel so that the solar panel is connected to the battery when the charger is not powered and disconnected when the charger is powered. The switching components may operate automatically and include a relay electrically connected to the charger so that the relay operates when the charger is powered.

Abstract: In a switchable impedance tester for measuring very small impedances, the effect of switch impedances is eliminated by connecting the test load between two switching transistors in their emitter-collector circuit, and driving them with operational amplifiers arranged to urge their inputs into equality. A test voltage source is connected across first inputs of the amplifiers, and the other inputs are connected between the respective transistors and the load. This produces an operational condition in which the voltage across the load is independent of the parameters of the switching transistors, i.e. the switching transistors appear to have zero impedance.