Abstract: An electrostatic chuck includes an insulating base body including a predetermined surface, and an electrode inside the base body, which is layer shaped along the predetermined surface. An upper surface of the electrode facing a side where the predetermined surface is located and the base body are in contact. A gap which is rendered a vacuum or filled with a gas is interposed between a side surface of the electrode and the base body.

Abstract: A communication apparatus and a congestion regulation control method which execute regulation control at the time of congestion, thereby improving communication quality. A congestion monitor monitors a congestion state, sets a congestion level and determines whether or not to perform regulation based on the congestion level. Traffic measuring unit measures the number of received signals as a traffic intensity. A traffic comparitor compares the traffic intensity with a preset traffic-regulation start traffic intensity when it is determined that regulation is to be performed. A regulation control means performs traffic regulation control when a comparison result shows that the traffic intensity is equal to or greater than the traffic-regulation start traffic intensity, and performs regulation control on a maintenance and operation process when the traffic intensity is smaller than the traffic-regulation start traffic intensity.

Abstract: Disclosed are a communication apparatus and a congestion regulation control method which flexibly and efficiently execute regulation control at the time of congestion, thereby ensuring an improved communication quality. Congestion monitoring means monitors a congestion state, sets a congestion level and determines whether or not to perform regulation based on the congestion level. Traffic measuring means measures the number of received signals as a traffic intensity. Traffic comparison means compares the traffic intensity with a preset traffic-regulation start traffic intensity when it is determined that regulation is to be performed. Regulation control means performs traffic regulation control when a comparison result shows that the traffic intensity is equal to or greater than the traffic-regulation start traffic intensity, and performs regulation control on a maintenance and operation process when the traffic intensity is smaller than the traffic-regulation start traffic intensity.

Abstract: The present invention relates to a communication service control apparatus for controlling communication services in the public network, private network or a network such as a virtual private network not accompanied by geographical conditions or physical conditions such as apparatus and more particularly to a communication service control apparatus for controlling the charging process for the communication services. The service control apparatus 2 comprises an information supply means 21 for supplying a charging control information including charging conditions about a plurality of customers for demanding the tariff of communication services, a charging decision means 22 for deciding, based on the charging control information, to charge for the predetermined customer among the plural customers, and a charging recording means 23 for recording charging result information based on the charging decision means.

Abstract: A pulse width distortion correction circuit in which a digital input signal has its leading and trailing edges smoothed, is added to an analog pulse width control signal and compared to a reference voltage to provide a digital output signal with a corrected duty ratio. A duty ratio detection circuit detects the duty ratio of the digital output signal and provides the corresponding pulse width control signal so as to cause the duty ratio to assume a value of 50%.

Abstract: A voltage/current conversion circuit giving an output current which is proportional to an input voltage. The circuit includes an operational amplifier to one input of which the input voltage is applied, first and second transistors, to the commonly connected bases of which the output of the operational amplifier is applied, and a feed-back path connecting the collector of the first transistor to the other input of the operational amplifier. With the circuit thus constructed, the output derived from the collector of the second transistor is in proportion to the input voltage.

Abstract: A voltage controlled attenuator includes a control circuit having variable impedance means whose impedance varies in a stepwise fashion as an input voltage is varied. In this manner, the attenuation characteristic of the attenuator can be made to vary stepwise in slope or inclination to improve its efficacy for use as a volume control device in audio apparatus.

Abstract: In feedback type amplifier including a differential transistor pair, the bias current to at least one of the differential transistors is provided by a source of current proportional to the DC currents through the differential pair, a first transistor connected in series with the current source and having its base coupled to the base of a second opposite conductivity type transistor so that both will conduct the same current, and a further transistor of the opposite conductivity type which is connected in series with the second transistor and provides its base current to one of the differential transistors.

Abstract: A signal switching circuit in which distortion caused by non-linearity of a signal path between a control electrode of an output transistor and a common junction output terminal is eliminated. The switching circuit includes plural amplifiers with outputs of the amplifiers being coupled to a common junction point and with a control signal coupled to each amplifier for enabling or disabling the amplifier. A by-pass impedance element having a linear voltage-current characteristic is coupled between the control electrode of each transistor and the common output junction point.

Abstract: A signal change-over amplifier for an FM receiver for switching over between AM and FM receiving modes without the addition of frequency response distortion or pop noise. The amplifier circuit includes two input signal control sections each of which includes a differential transistor pair. Activating current is fed to the emitters of the differential transistor pairs by a constant current source which is activated in response to the input control signal. The collectors of the transistor of the two input control sections are interconnected. The base of one transistor of one pair is coupled to the base of the corresponding transistor of the other pair. The input information-bearing signals are coupled to the bases of the other transistors in the two pairs. The interconnected collectors are coupled respectively to a transistor pair in an output section to which current is fed by a current mirror circuit. The final output is provided by a push-pull circuit.

Abstract: A push-pull amplifier circuit comprises first and second output transistors whose emitters are commonly connected respectively through resistors to an output point, together with base biasing circuits connected between the bases of the first and second output transistors, to perform push-pull operation. The base biasing circuits comprise first and second current detecting elements for detecting the currents of the first and second output transistors, first and second variable bias generators controlled by the first and second current detecting element and reference bias generators. The operations of the first and second output transistors are effected in the active regions at all times.

Abstract: An output amplifying circuit which comprises a Push Pull amplifier section, a power supply circuit section and an amplifier section for amplifying a power source. The circuit eliminates an occurrence of switching distortion and minimizes heat loss therein. The input terminals of the Push Pull amplifier section and the power source amplifier section are connected in common, while the positive and the negative terminals of the power source amplifier section are connected to those of the power supply circuit section, respectively.

Abstract: A push-pull amplifier having a pair of output transistors and a pair of emitter coupled resistors, one terminal of each resistor coupled to an emitter of a respective transistor and the other terminals being commonly connected to an output point. A comparison circuit is employed for comparing the voltages across each of the emitter resistors with a predetermined voltage. A bias circuit is connected in series between the bases of the output transistors and a short circuit controlled by the output of the comparison circuit selectively shorts a resistor element in the bias circuit.