Abstract: A waterproof connector comprises: a connector housing (29, 89) formed with a plurality of terminal accommodation chambers (27, 93) for accommodating a plurality of terminal parts (53, 117), respectively and with a seal hood portion (39, 105); and a sealing member (25, 91) fitted to the seal hood portion of the housing and formed with a plurality of seal locating projections (47, 109) each having an insertion hole (45, 107) at a center thereof. A plurality of terminal parts (53, 117) connected to wires (51, 115), respectively are inserted into the terminal accommodation chambers of the housing, through the wire insertion holes of the sealing member fitted to the seal hood portion of the housing, respectively under watertight conditions.

Abstract: A catalyst for hydrogenolytic dealkylation comprising rhodium on a crystalline metallo-silicate carrier and a process for hydrogenolytically dealkylating a hydrocarbon mixture mainly comprising alkyl aromatic hydrocarbons in the presence of such a catalyst are disclosed. The catalyst exhibits catalytic activity at low temperatures and high reaction selectivity and has a prolonged duration.

Abstract: A pair of equilibrium output signals P(+) and P(-) from a 1-bit D/A converter IC, which is made up of an oversampling filter, noise shaper and a pulse converter, are supplied to a pair of field effect transistors connected in a common drain configuration. A constant current I.sub.0 is supplied to the common drain from a constant current source and at least one of the source output currents is converted by an output circuit into a voltage. In this manner, a 1-bit D/A converted output signal freed of fluctuations of the power source is provided at an output terminal.

Abstract: In a terminal protection type connector in which a flexible locking arm for locking a female connector housing is provided on a male connector housing, and the elastic contacts of terminals accommodated in the male connector housing are exposed through openings formed in the latter, a terminal protecting member is slidably mounted on the male connector housing in such a manner that said terminal protecting member covers the openings and engages with the flexible locking arm.

Abstract: In locking metal terminals in a connector, a terminal locking jig having engaging prongs which are extended respectively so as to be engaged with terminal accommodating chambers in the rear end portion of a connector housing is inserted into a terminal-locking-member accommodating chamber formed surrounding the terminal accommodating chambers, to drive the metal terminals which are not completely locked yet to the positions where the metal terminals are completely locked, and thereafter a terminal locking element having engaging prongs which are extended in the same manner is inserted into the connector housing from the rear or side. Thus, the terminal locking member can be engaged with the connector housing with ease.

Abstract: A low insertion-withdrawal force electric connector is disclosed wherein a pin is mounted on one side wall of a male housing; a groove into and out of which said pin is movable is provided in a hood of a female housing; a cam lever is pivotally mounted on said hood; and the cam lever has at its front end an eccentric cam groove which is engageable with the pin so as to cause said two housings to be fitted and disengaged relative to each other in response to the pivotal movement of said lever. A fitting-side acting surface of the eccentric cam groove against the pin is disposed generally perpendicular to the direction of advance of said pin when the two housings are completely fitted together.

Abstract: A digital-to-analog converter utilizing a PWM system for converting input digital data to PWM signals and finally to an analog signal divides the sampling period of the input digital data into an even number of sampling periods and produces PWM signals with equal pulse widths corresponding to the input digital data each divided sampling period, whereby a simple structure is provided to reduce harmonic distortion and obtain a high quality analog signal.

Abstract: A noise shaping circuit includes a first degree noise shaping arrangement in which a quantization error component at a first quantizer adapted for quantizing input signals is fed back to an input side, and in which a quantization error component at the first quantizer is fed back by a predetermined feedback circuit to an input of the first quantizer. The feedback circuit includes a synthesizing unit supplied with an error signal from a first quantization error output unit, a second quantizer for quantizing an output signal from the synthesizing unit, a second quantization error output unit for taking out a quantization error at the second quantizer, a transfer characteristic unit having predetermined transfer characteristics, and a differentiation unit supplied with output signals from the second quantizer. Error signals from the second quantization error output unit are supplied to the transfer characteristic unit, the output of which is supplied to the synthesizing unit.

Abstract: A signal processing apparatus reduces the quantization noise by using so-called noise shaping circuits. The input signal may be audio or video signals. One of the noise shaping circuits is supplied with a signal which is the relative addition of the input signal and a dither while the other noise shaping circuit is supplied with a signal which is the relative subtraction of the input signal and the dither. The signal components of the outputs of the noise shaping circuits are effectively combined to cancel the dither components to produce an output with an improved S/N ratio. A plurality of such signal processing apparatus may be arranged in parallel, in which case different dithers are used in the respective signal processing apparatus and the outputs of the respective signal processing apparatus are combined to further improve the S/N ratio.

Abstract: A PWM digital-to-analog converter is disclosed in which a value representing a differential between a first pulse width modulated waveform based upon input digital data and a second pulse width modulated waveform representing a 2's complement version of the input digital data is produced by a differential amplifier and high frequency components thereof are attenuated to produce an analog output signal and with an improved distortion factor.

Abstract: Sulphur dioxide is removed from a stack gas by bringing said gas containing SO.sub.2 into contact with an absorbing solution prepared by adding an hydroxide of a metal from either Groups II, III and VIII of the periodic Table to an aqueous solution of a halide of said metal, wherein the hydroxide is present in an amount of from 0.3 to 0.8 weight percent.