Abstract: There is provided a signal processing device including a signal generation unit that generates a control signal for controlling an imaging device connected via one cable, a signal superimposition unit that superimposes the control signal generated by the signal generation unit on a video signal received from the imaging device via the cable without an influence on display of a video corresponding to the video signal, and a transmission unit that transmits the signals superimposed by the signal superimposition unit to the imaging device via the cable.

Abstract: Disclosed herein is a signal receiving apparatus including: a resonance section configured to receive an input signal at a variable resonance frequency; a signal supplying section configured to supply an electrical signal having a desired reception frequency to the resonance section; a mixture section configured to mix a resonance signal, which is output by the resonance section when the resonance section receives the electrical signal from the signal supplying section, with a switching signal having the desired reception frequency; and a control section configured to change a resonance characteristic of the resonance section and measure the phases of mixed signals output by the mixture section before and after the resonance characteristic changing operation to control the resonance frequency of the resonance section in order to change the resonance frequency in a direction to reduce a difference between the phases of the mixed signals before and after the resonance characteristic changing operation.

Abstract: Disclosed herein is a signal receiving apparatus including: a resonance section configured to receive an input signal at a variable resonance frequency; a signal supplying section configured to supply an electrical signal having a desired reception frequency to the resonance section; a mixture section configured to mix a resonance signal, which is output by the resonance section when the resonance section receives the electrical signal from the signal supplying section, with a switching signal having the desired reception frequency; and a control section configured to change a resonance characteristic of the resonance section and measure the phases of mixed signals output by the mixture section before and after the resonance characteristic changing operation to control the resonance frequency of the resonance section in order to change the resonance frequency in a direction to reduce a difference between the phases of the mixed signals before and after the resonance characteristic changing operation.

Abstract: A radio communication apparatus using a direct conversion method capable of receiving a radio signal having a predetermined frequency band. The radio communication apparatus includes: a low-noise amplifier section including one or a plurality of low-noise amplifiers receiving input of a receiving signal having a predetermined frequency band; and a mixer section including in-phase and quadrature mixers demodulating an output of the low-noise amplifier into in-phase-component and quadrature-component signals, respectively, wherein the mixer section includes a capacitor in an input section, separates the in-phase component and the quadrature component by the capacitor, and supplies the components to the corresponding in-phase and quadrature mixers, respectively.

Abstract: A radio communication apparatus using a direct conversion method capable of receiving a radio signal having a predetermined frequency band. The radio communication apparatus includes: a low-noise amplifier section including one or a plurality of low-noise amplifiers receiving input of a receiving signal having a predetermined frequency band; and a mixer section including in-phase and quadrature mixers demodulating an output of the low-noise amplifier into in-phase-component and quadrature-component signals, respectively, wherein the mixer section includes a capacitor in an input section, separates the in-phase component and the quadrature component by the capacitor, and supplies the components to the corresponding in-phase and quadrature mixers, respectively.

Abstract: A radio receiver of the is provided with a local oscillation circuit, a mixing circuit to perform a frequency conversion from a received signal into an intermediate frequency signal by using an oscillation signal generated by the oscillation circuit, an ALC circuit to detect a level of the oscillation signal and control the level of the oscillation signal at a specified value, and a switching circuit switch the operation of the ALC circuit from the operational state to the non-operational state and vice versa. The receiver thus constructed will not receive an influence from the image signal, and even when the receiver is used in an area where a strong interference wave is present, the receiver is able to operate the local oscillation circuit in a normal condition.

Abstract: An amplifier for amplifying a high frequency signal includes comprises cascade-connected an input npn transistor and an output npn transistor and a bias circuit to control a base current Ib of the input transistor in order to make a DC component of a collector current Ic of the cascade-connected npn transistors constant. A shunt transistor is further connected between a base electrode of the input npn transistor and one terminal of a power source and is connected so that the base current of the input npn transistor flows through a resistor connected between a base electrode and an emitter electrode of the shunt transistor. By lowering a base voltage of the output npn transistor in response to a gain control signal, the collector current Ic is reduced, and a gain of the amplifier is reduced, and simultaneously the shunt transistor is made in shunting operation.

Abstract: The radio receiver of the present invention is provided with a local oscillation circuit, a mixing circuit to perform a frequency conversion from a received signal into an intermediate frequency signal by using an oscillation signal generated by the oscillation circuit, an ALC circuit to detect a level of the oscillation signal and control the level of the oscillation signal at a specified value, and switching means to switch the operation of the ALC circuit from the operational state to the non-operational state and vice versa. The receiver thus constructed will not receive a bad influence from the image signal, and even when the receiver is used in an area where a strong interference wave is present, the receiver is able to operate the local oscillation circuit in a normal condition.

Abstract: To make variable time constant of an AGC loop of an AGC circuit, there is provided an AGC circuit including a control circuit for controlling a level of an input signal and outputting an output signal, a rectifying circuit for rectifying the output signal from the control circuit and outputting a voltage V DET having a level in correspondence with a level of the output signal and a voltage to current converting circuit for converting the output voltage V DET from the rectifying circuit into a current. The voltage to current converting circuit is constituted to provide a differential amplifier supplied with the output voltage V DET from the rectifying circuit. A current I DET outputted by the differential amplifier is converted into AGC voltage V AGC by being supplied to a capacitor. By the AGC voltage V AGC, AGC is carried out by controlling the level of the input signal at the control circuit.

Abstract: An apparatus for receiving carrier wave signals includes a frequency converting portion operative to produce an intermediate frequency signal having a carrier frequency of an intermediate frequency, a frequency demodulator for frequency-demodulating the intermediate frequency signal with a demodulation characteristic having a center frequency substantially equal to the intermediate frequency.

Abstract: A pulse counting FM demodulator includes a differentiating circuit that differentiates an FM intermediate-frequency signal to produce a differentiated pulse signal. A trigger signal is generated based on the differentiated pulse signal and is used to control the charging and discharging of a capacitor that is included in a monostable multivibrator. The charging and discharging of the capacitor provides an output level inverting operation. A variable current source supplies the capacitor with a charging current that is varied in response to an externally supplied control voltage, and an output circuit provides a demodulated output signal having a level corresponding to the output level inverting operation in the monostable multivibrator.

Abstract: A broadcasting signal receiving apparatus includes a first signal receiving portion for receiving selectively frequency-modulated broadcasting signals to obtain a frequency-modulated intermediate frequency signal, a first band pass filter through which the frequency-modulated intermediate frequency signal passes, a first demodulator for frequency-demodulating the frequency-modulated intermediate frequency signal to obtain a first demodulation output signal, a second signal receiving portion for receiving selectively amplitude-modulated broadcasting signals to obtain an amplitude-modulated intermediate frequency signal, a second band pass filter through which the amplitude-modulated intermediate frequency signal passes, a second demodulator for amplitude-demodulating the amplitude-modulated intermediate frequency signal to obtain a second demodulation output signal, an output portion for obtaining a reproduced information output based on one of the first and second demodulation output signals, a signal supplyi

Abstract: An AM radio receiver of a double superheterodyne type. Where a first intermediate frequency is selected to be a low frequency of several kHz other than 0 kHz. A second intermediate frequency is selected to be several tens of kHz. A first local oscillator circuit formed of a PLL generates first local oscillation signals of two kinds whose phases are different from each other by 90.degree.. First and second mixer circuits are respectively supplied with the first local oscillation signals of two kinds and mix them with a received signals to generate the first intermediate frequency. First and second filters obtain signals each having the first intermediate frequency. A second local oscillator circuit generates second local oscillation signals of two kinds whose phases are different from each other by 90.degree.. Third and fourth mixer circuits are respectively supplied with the signals having the first intermediate frequency and mix them with the second local oscillation signals.

Abstract: An equivalent variable resistor circuit for use in an integrated circuit includes a signal path extending from a signal input terminal through a first resistor to a signal output terminal, a first transistor having its collector connected with a signal output portion of the signal path between the first resistor and the signal output terminal, a second transistor having its collector connected with a DC voltage source and its emitter connected with an emitter of the first transistor for forming a differential pair with the first transistor, a third transistor having its collector connected with the emitters of the first and second transistors connected with each other and its emitter connected through a second resistor to a reference potential point to form a voltage to current converting portion with the second resistor, and a voltage controlling portion provided for varying a DC voltage supplied between bases of the first and second transistors, so as to vary equivalently a resistance of the signal path bet

Abstract: An interface circuit for an audio signal includes a low-pass filter supplied with an audio signal with a DC component superposed thereon from a first circuit for extracting the DC component and a differential-input circuit. The differential-input circuit is supplied with the audio signal with the DC component superposed thereon from the first circuit and also supplied with the DC component extracted by the low-pass filter and the output of the differential-input circuit is supplied to a second circuit. In the differential-input circuit, the DC component superposed on the audio signal from the first circuit is canceled by the DC component from the low-pass filter so that only the audio signal is supplied to the second circuit. With the above described arrangement, terminal pins of an IC can be reduced in number.

Abstract: An amplifier in which a current mirror circuit 53 is formed of a transistor Q25 on the input side and a transistor Q26 on the output side. The base-emitter junction area of the transistor Q26 is set to be N (N>1) times as large as that of the transistor Q25. A parallel circuit of a resistor R25 and a capacitor C25 is connected between the base of the transistor Q25 and its bias point Q27. A resistor R26 is connected between the base of the transistor Q26 and the bias point Q27. The resistance value of the resistor R25 is set to be virtually N times as large as the resistance value of the resistor R26. When an input current i25 is supplied to the transistor Q25, an output current i26, which is N times as large as the input current, is obtained from the transistor Q26 on the output side, whereas the output current i26 is held lower than N times of the input current i25 when the frequency of the input current is high.

Abstract: This invention relates to a process for treating the waste gas discharged from a urea prilling tower and an apparatus therefor. More particularly, this invention relates to a process for treating the waste gas discharged from a urea prilling tower and an apparatus therefor, characterized by that a continuous liquid or water film flow (hereinafter called merely a liquid film) of a scrubbing solution and/or an absorption liquid (hereinafter called merely a scrubbing solution) is formed so as to traverse across the whole passage of the waste gas within the scrubbing tower, and when the waste gas passes through such a liquid film the fumy minute particles (hereinafter called fumes) of urea, about 1 micron in size, which are contained in said waste gas, are removed by contacting with the scrubbing solution.