Abstract: A circuit for providing a DC output equal to the RMS value of a time-varying input signal, the circuit including: (i) an RMS-to-DC converter for producing the DC output and (ii) a high-order low-pass filter comprising at least first and second low-pass filters connected in series to cooperatively reduce at least one of ripple in the DC output, ripple in an denominator feedback loop, or DC error in the DC output.

Abstract: A circuit for providing a DC output equal to the RMS value of a time-varying input signal, the circuit including: (i) an RMS-to-DC converter for producing the DC output and (ii) a high-order low-pass filter comprising at least first and second low-pass filters connected in series to cooperatively reduce at least one of ripple in the DC output, ripple in an denominator feedback loop, or DC error in the DC output.

Abstract: A converter circuit operable in a current control mode is disclosed. The circuit is of the type including an (1) inductor, (2) a clock for providing a clocking signal so that the circuit operates as a synchronous converter and (3) switching means, responsive to the clocking signal and a threshold current, for controlling the load voltage across the inductor between at least two different levels of voltage as a function of one or more supply voltages so that the inductor conducts (a) increasing inductor current for one level of load voltage from the beginning of each cycle of the clocking signal until the inductor current equals the threshold current during each cycle, and (b) decreasing inductor current for the other level of voltage from the time in each cycle the current equals the threshold current until the end of each said cycle.

Abstract: An electrical circuit arrangement for filtering electrical brush noise transmitted from an open switching wire connected at one end to an intermittently used brush of a multi-speed electric motor driven by a power source and having an electrically grounded housing and stator, said circuit arrangement utilizing a switching transistor located in close proximity to said brush and motor.

Abstract: Disclosed is an electronic piano circuit arrangement which combines a multitude of different frequencies within a resistordiode matrix array. The resistor-diode coupling elements provide a different value impedance for various signals to be combined and the amplitude of the signals are predetermined to electronically produce a piano sound which substantially corresponds to the sound of an actual piano tone.