Abstract: An input unit enters two reference signals having respective different frequencies at a stage preceding a power amplifier. The reference signals are delivered through a predistortion circuit to a power amplifier, and supplied from a predetermined section of the power amplifier. The signals from the power amplifier contain a third-order intermodulation distortion component. Based on the signals from the power amplifier, an extracting unit extracts a frequency component having a frequency which is twice the difference between the frequencies of said two reference signals. A detecting unit detects the extracted frequency component thereby to output a DC voltage. Since the extracted frequency component is correlated to the third-order intermodulation distortion component, the DC voltage represents the magnitude of the third-order inter-modulation distortion component.

Abstract: The present housing for coin selectors is provided with an electronic circuit wherein are included elements for measuring the variation of the field produced by the passage of coins through a magnetic field generated by a group of coils, said housing being provided, on one of its faces (9) corresponding to the paths of coins, with various ribs (10) parallel to each other and parallel with the rolling ramp for the coins, preferably three ribs, with self-cleaning effect which avoids the deposition of dirt entrained by the coins.

Abstract: An apparatus and method for determining the rate of rotation of a body rotating with an angular velocity .omega. about a first axis. The apparatus comprises a housing adapted to be fixed to the body so as to rotate with the angular velocity .omega. about the first axis and a mechanical system within the housing having more than two degrees of freedom. Electromagnetic drive coils are provided for applying a forced vibration to the mechanical system about a second axis substantially perpendicular to the first axis, thereby producing a Coriolis response along a third axis mutually perpendicular to the first and second axes, the forced vibration having a predetermined magnitude and a frequency which is constrained to lie within a predetermined range such that there is produced a coupling between the degrees of freedom whereby the magnitude of the Coriolis response is substantially insensitive to frequency.

Abstract: A gain control circuit for an amplifier having a stepwise variable gain is disclosed, which includes a peak detector detecting and holding a peak value of an output voltage of the amplifier, a reference voltage generator generating first and second reference voltages having values different from each other, a comparator circuit comparing the peak value with the first and second reference voltages, and a control circuit responding to a comparison output derived from the comparator circuit and controlling the gain of the amplifier one step by one step such that the peak value becomes to intervene between the first and second reference voltages. When the peak value exists between the first and second reference voltages, the control circuit holds the gain of the amplifier at the current value, so that the amplitude of the output voltage is controlled to be substantially constant.

Abstract: Recovery of citric acid from a citric acid fermentation broth.

Abstract: Apparatus for measuring an electrical quantity comprises a fixed body and a movable device having a pivot shaft fixed to an indicator needle which moves in front of a graduated scale. The movable device is pivotably mounted in the fixed body by pivot pins and corresponding bearings. The pivot pins are provided at the ends of the shaft while the bearings face the pins on the fixed body. The movable device is further supported relative to the fixed body by knives and corresponding bearings which receive edges of the knives. The knives are fixed to the movable device and the bearings are provided near the ends of the shaft. The edges of the knives and the pivot pins together with the corresponding bearings are aligned with each other.

Abstract: A hermetic adjustable hose clamp to be used on hoses and the like of different diameters, comprises a strap having two parallel loops and two cylinders inserted in the two loops. A clamping tension is applied to the strap surrounding the hoses by an adjustable screw which joins the two cylinders which are supported at both loops of the strap.

Abstract: A method and a circuit for exciting an ultrasonic generator comprises a control loop which includes the ultrasonic generator itself and a voltage-controlled oscillator. The control loop keeps the active power consumption to a desired value, which is compared in a comparator with the instantaneous active power consumption. One output of a further rectangular oscillator is connected to the control input of the voltage-controlled oscillator. The rectangular oscillator is put into operation if in the control loop there are no control oscillations or only those which are smaller than a predetermined threshold. The output of the rectangular oscillator is connected across one diode to the control input of the voltage-controlled oscillator and across another diode to the controlled input of comparator. The additional signal is applied to the voltage-controlled oscillator, apart from the control signal of the control loop.