Sony Corporation

Gakko Hojin Tokai University

Yoshio Shimizu

Yoshio Kato

Kazuichi Seki

Satoshi Yokoya

A signal level detecting circuit comprises an input terminal to which an input signal with level variations is applied, a level comparator operative to compare the level of the input signal with the level of a reference signal variable in level and to produce a comparison output signal having first and second levels in response to differences between the level of the input signal and the level of the reference signal, a control signal generator operative to produce control signals one of which is obtained when a period of time in which the comparison output signal has the first level is not longer than one of two different reference periods of time and the other of which is obtained when the period of time in which the comparison output signal has the first level is not shorter than the other of two different reference periods of time, a pulse generator operative to produce a pulse signal having its pulse duty factor varied in response to the control signals obtained from the control signal generator, and an integrator operative to produce an integration output signal based on the pulse signal obtained from the pulse generator and to supply the level comparator with the integration output signal as the reference signal.

Signal level detect circuits

A signal mixing circuit for blending two signals, such as left and right channel FM stereo signals, blends the two signals at each of two outputs in response to a variable control voltage, which acts upon a transistor network connected between the two signal paths. When the variable control voltage is determined by an amplitude detector connected in a conventional FM stereo receiver, the output signals will be blended to a greater degree when the received signal strength of the broadcast FM signal becomes weaker. In a further embodiment, capacitors are added to inhibit high-frequency components of one channel and to add in high-frequency components of another channel thereby eliminating and cancelling the noise components normally present in the respective signals and improving the S/N ratio.

Signal mixing circuit

A signal comparing circuit includes a differential amplifier in which first and second amplifier input signals derived from respective circuit input signals are compared with each other to provide an output signal the level of which depends on the relative levels of the amplifier input signals, and the signal comparing circuit has a hysteresis width, which is defined as a range of relative levels of the input signals within which the output signal level does not change. A variable gain attenuator circuit is connected to the differential amplifier at an input thereof and includes a switching circuit that changes the circuit gain in response to changes in the output signal level. The attenuator circuit gain changes so that at least one amplifier input signal is provided at two levels, with the difference between such two levels depending on the level of at least one of the circuit inputs. The attenuator circuit thus varies the hysteresis width in response to said at least one circuit input signal level.

Signal comparing circuit

In a space diversity receiver for receiving broadcast signals and having first and second antennas coupled to first and second receiving circuits, respectively, for supplying first and second output signals therefrom to a switching circuit which normally selectively supplies the one of the output signals detected to have a superior or better signal to noise ratio; a judging circuit is provided for comparing the better signal to noise ratio of an output signal with a predetermined value and for producing a stop or inhibiting signal when the signal to noise ratio is lower than the predetermined value, and such inhibiting signal temporarily causes the switching circuit to stop switching between the output signals and to continuously supply one of the output signals.

Space diversity receiver

A pilot signal detecting circuit for use in an AM stereo receiver capable of receiving and demodulating AM stereo signals broadcast according to any of several different AM stereo modulation methods, in which the particular method employed in broadcasting the AM stereo signals is determined by detecting the individual pilot signal and providing an indication of the particular method employed in modulating the broadcast AM stereo signal. Replicas of each of the different pilot signal frequencies in each of the different AM stereo modulation systems are generated and a signal containing the pilot signal is extracted from the demodulated received AM stereo signal. The replicas are compared with the extracted pilot signal to determine the identity of the AM stereo modulation system employed in the received AM stereo signal. A phase-locked-loop is employed to extract the pilot signal from the received signal and a synchronous detector and envelope detector are employed to demodulate the left and right channel stereo signals from the received AM stereo signal. Comparison of the replica and the received pilot signal is performed in identical phase detectors which receive a corresponding replica of the pilot signal produced by another phase-locked-loop and a frequency divider.

Pilot signal detecting circuit for AM stereo signals

Wind power turbines are largely divided into vertical axis type wind power turbines and propeller type (horizontal axis type) wind power turbines. The present invention discloses a vertical axis type wind power turbine. The airfoil of blades in this vertical axis type wind power turbine is formed in such manner that, denoting a proper position on the airfoil chord line as a camber reversing position, a camber having a downward convex curvature is given between said position and a leading edge and a camber having an upward convex curvature is given between said position and a trailing edge so as to be a mean line and a rational thickness distribution is given to this mean line. This vertical axis type wind power turbine is formed by keeping the spanwise direction of the above mentioned blade parallel with a vertical rotary axis and fitting a plurality of blades at regular intervals at a distance to the vertical rotary axis through respective supporting arms.

Vertical axis type wind power turbine

Wind turbines are largely divided into vertical axis wind turbines and propeller (horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with a starting and braking control system. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotary axis by keeping the blade span-wise direction in parallel with said axis and being provided with a low speed control windmill in which the radial position of each operating piece varies with a centrifugal force produced by the rotation of said vertical rotary axis.

Vertical axis wind turbine

Wind turbines are largely divided into vertical axis wind turbines and propeller (horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with rotational speed control systems. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft and being provided with aerodynamic control elements operating manually or automatically to control the rotational speed of the turbine.

Growing community of inventors

Kanagawa, Japan

Yoshio Shimizu