Abstract: A baseband signal communication apparatus includes a transmission unit and a reception unit. The transmission unit superposes a subcarrier on one value of a baseband signal consisting of binary values, modulates a carrier with the baseband signal on which the subcarrier is superposed, and transmits the baseband signal as a transmission signal wave. The reception unit demodulates the baseband signal having the subcarrier superposed thereon by using a demodulator upon reception of the transmission signal wave, extracts the subcarrier from the demodulated signal by using a bandpass filter, and demodulates the baseband signal by causing a detector to detect an envelope of the subcarrier.

Abstract: A moisture sensitive element includes a moisture sensitive film consisting of a polymer obtained by polymerizing and crosslinking a fluorine-containing polyimide oligomer or a polyisoimide oligomer having acetylene as a terminal group and its isomer. The moisture sensitive element also includes electrodes formed on upper and lower surfaces of the moisture sensitive film.

Abstract: A proportional combustion control device for supplying fuel to a combustor for a boiler, a hot water maker, etc., comprising an opening and closing valve for controlling a supply of fuel provided in the midst of a fuel supply pipe, and a control valve having a spindle whose needle portion at the extreme end is moved in and out of a nozzle and an exciting coil to generate a drive force for intermittently and axially moving said spindle against the restoring force by being supplied with a drive pulse, wherein even if fuel is either oil or gas, proportional control of combustion can be made, and the spindle is intermittently moved in the range capable of continuously carrying out combustion to open and close the nozzle whereby jetting of fuel is subjected to proportional control at the turndown ratio of 1/5 to 1/10 to always render the stabilized combustion possible.

Abstract: A dust collecting cell for a dust collector has a plurality of first electrode plates, a plurality of second electrode plates each disposed between the adjoining two of the first electrode plates in a parallel and spaced apart relation thereto, and a block defining a plurality of resistors having a high value of resistance which are connected between the first or second electrode plates and a source of high voltage supply. Even if a dielectric breakdown may occur between any two adjoining electrode plates, the resistors ensure that the discharge take place only as a local phenomenon, and that the cell make only a low noise accompanying the discharge.

Abstract: In this sensitive, relatively inexpensive to manufacture, photo-detector, one surface of an amorphous silicon photovoltaic element is bonded to a thin transparent conductive layer formed on an insulating base. A conductive pattern is formed on the opposite surface of the element. The conductive layer may be formed of indium-tin oxide (ITO) and the photovoltaic element may be an element with an intrinsic semiconducting layer between p and n doped layers. The photovoltaic element generates component currents in response to photons passing through the transparent base and conducting layer. Those current components flowing predominantly in a direction at right angles to the photovoltaic element surfaces are summed by the conductive pattern which acts as a spatial filter, responsive to desired ones of these components and relatively unresponsive to other current components.

Abstract: In a microwave electric power receiver, a microstrip resonator having a line length 1/2 of a wavelength of a microwave to be received is notched to be split at its longitudinally central portion into two portions. A rectification diode is interposed between notched end portions of the microstrip resonator portions to be matched therewith. The diode generates a DC power.

Abstract: A microwave responder resonates or does not resonate with a microwave transmitted from a radio transmitter, and radiates the resonated microwave as a response signal wave. Two microstrip lines are linearly arranged to be separated from each other at a predetermined interval. A diode which is switched between ON and OFF states in response to the response signal is interposed between two end portions of the microstrip lines separated by the predetermined interval, and a distance, between distal ends of the two linearly arranged microstrip lines, which includes an impedance defined by the ON or OFF state of the diode is determined to be 1/2 a wavelength of the microwave.

Abstract: A respiratory air flowmeter includes a flow path forming member, a restricting portion, rectifying lattices, and a sensor. The flow path forming member forms a flow path in which respiratory air flows. The restricting portion and the rectifying lattices are arranged in the flow path in order to stabilize a respiratory air flow. The sensor is mounted in a sensor mounting portion of the flow path forming member, and detects a flow rate of respiratory air flowing in the flow path.

Abstract: A zero point compensating circuit for a microbridge flow meter including an upstream thermal sensor means, a downstream thermal sensor means and a heater means located between said upstream and downstream thermal sensor is provided which comprises a first switch coupled to said heater for turning on and off the same and a current supply circuit coupled to said upstream and downstream thermal sensors for selectively supplying the same with a first current when said first switch is closed and a second current larger than said first current when said first switch is opened such that said upstream and downstream thermal sensors reach a temperature to which they are heated when said heater is on in no flow condition. Thus, an offset caused by discrepancy in the resistance value and thermal coefficients of resistance (TCR) of the upstream and downstream temperature sensors can be removed by the above circuit, thereby making it possible to achieve a precise measurement of small flow rates of a fluid of interest.

Abstract: A temperature compensating circuit having a third temperature sensor element for detecting an ambient temperature disposed on the same substrate on which first and second temperature sensor elements are located, and a voltage across the third sensor element, generated by supplying a current thereto, is applied to the first and second sensor elements. Therefore, a voltage applied to first and second sensor elements is automatically changed corresponding to change in ambient temperature, and accordingly a difference in temperature between first and second sensor elements can be precisely detected in a form of voltage signal.

Abstract: A moisture-sensitive element comprising a moisture-sensitive film which consists of a polymer (such as a polymer in which polyethersulfon is a principal component) whose water sorption amount is between 10 and 40 mg/g at a temperature of 30.degree. C. and a relative humidity of 90% RH. The temperature-sensitive element has a low temperature dependency, a small hysteresis and a quick response and accordingly can be employed in a wide range of temperature as well as in a severe condition such as high humidity, high temperature, cyclically fluctuating humidity, low humidity, moisture condensation, water dipping and so on.

Abstract: A microbridge flow sensor includes integral bridge portions and temperature-measuring resistive elements. The bridge portions are integrally formed above the right and left openings of a substrate, respectively. The temperature-measuring resistive elements are respectively formed on the surfaces of the bridge portions.

Abstract: A combustion control device capable of detecting a self-discharge state caused by a failure of an ultraviolet ray detecting tube by interrupting flames from a combustion mechanism to an ultraviolet ray detecting tube by opening and closing a shutter, integrating, by an integrating circuit, detection signals from this ultraviolet ray detecting tube only when the shutter is closed, comparing the result of this integration with a preset judgement level by use of a first judgement circuit, and determining a failure by comparing a result of this comparison with a preset failure judgement frequency by use of a second judgement circuit, thereby improving maintainability.

Abstract: This flow meter uses two known flow responsive techniques and combines them in a unique structure and system to form an improved flow meter whose range extends from low to high flow rates. The meter comprises a flow tube with a region of reduced diameter between its inlet and outlet. A microbridge flow sensor of a suitable type known in the art, which responds to thermal changes caused by changes in the flow rate, is located in the region of reduced diameter. A post downstream of the microbridge sensor creates Karman vortices whose frequencies are a function of flow rate and which are detected through ports in the tube by a suitable detector. The output of the microbridge is linear from low flow rates to a mid range and the Karman flow meter output is linear from the mid range to high flow rates. A correction factor is applied to the thermal flow meter output.

Abstract: A flow sensor comprising a flow passage, a rectifying element such as a plurality of screens or a honeycomb structure or both, arranged in the flow passage, a flow passage reducer for reducing the flow passage behind the rectifying element, and a thermal flow sensor, such as for example a micro bridge sensor, mounted at a location immediately behind the reducer. The above structure can largely reduce disturbance in flow to thereby enable highly accurate measurements of a wide range of flow without a low pass filter.

Abstract: A flow control valve comprising a main valve for opening and closing a fluid conduit, an electromagnetic coil for driving the main valve, a diaphragm responsive to the action of the main valve, a sub-valve chamber partitioned by the main valve and the diaphragm, a sub-valve incorporated in the main valve for opening and closing the sub-valve chamber to a conduit in the secondary side, a projection, protrusively formed on a driving shaft of the electromagnetic coil, responsive to a driving force of the electromagnetic coil for sliding the sub-valve by a predetermined stroke to bring the same in a fully opened state with the main valve remaining in a closed state and thereafter opening the main valve, a bleed orifice provided through a side wall of the main valve for making the pressure in the sub-valve chamber equal to a primary pressure; and a returning spring for urging each of the main valve and the sub-valve in the closing direction.

Abstract: An electromagnetic flowmeter includes a measuring pipe and a cylindrical case. The measuring pipe has a pair of pipe connecting flanges at both ends of its outer surface. The cylindrical case surrounds the outer surface of the measuring pipe so as to cover a pair of excitation coils arranged on the outer surface of the measuring pipe, and is welded and fixed to ring-like collar portions extending from inner surfaces of the flanges. The thickness of the ring-like collar portions to which the case is welded and fixed is set to be larger than that of the case.

Abstract: A bridge balancing circuit includes a bridge having a resistance change type sensor, a differential amplifier for extracting a voltage difference across two central nodes of the bridge, a comparator connected to the output terminal of the differential amplifier, a D/A converter an output terminal of which is connected to one of the two central nodes, and a controller for controlling the D/A converter. The differential amplifier and the comparator automatically detect a balanced point of the bridge, and the controller maintains a balanced state of the bridge.

Abstract: A full duplex transponder system includes an interrogation apparatus and a transponder apparatus. The transponder apparatus includes a reception antenna for receiving an interrogation signal wave whose carrier wave is phase- or frequency-modulated with an interrogation signal, a demodulator for demodulating the interrogation signal from the interrogation signal wave received by the antenna, a rectifier for rectifying the carrier wave of the interrogation signal wave received by the antenna and outputting a DC power used as a drive power source of the transponder apparatus, a multiplier for generating a predetermined harmonic component from the carrier wave of the interrogation signal wave received by the antenna, a modulator for amplitude-modulating the harmonic component with a response signal, and a transmission antenna for transmitting a response signal wave output from the modulator.

Abstract: A current holding circuit of a two-wire instrument which includes a transmitter and a receiving resistor, remotely located from the transmitter, for detecting a signal from the transmitter as a change in loop current, and to which a commuication device is connected, includes a current detecting unit, a sample-hold unit, and a current control unit. The current detecting unit includes a reference resistor for converting the loop current into a voltage and a first operational amplifier for receiving the voltage obtained by the reference resistor at the noninverting input terminal. The sample-hold unit holds an output from the current detecting unit. The current control unit supplies an output from the sample-hold unit to the inverting input terminal of the operational amplifier and controls the loop current on the basis of the output from the operational amplifier, thereby holding the loop current at a constant value.