Abstract: In a photoelectric detector having a light transmitting section and a light receiving section disposed remote from each other, intermittent illumination of a light source of the light transmitting section is detected and processed by the light receiving section in synchronism with the intermittent illumination by way of power lines interconnecting the light transmitting and light receiving sections. To this end, a circuit for intermittently supplying a power source to the light transmitting section is provided in the light transmitting section or the light receiving section and the intermittent power supply is utilized as a synchronizing signal to intermittently illuminate the light source and to allow the light receiving section to transmit and process a received light signal or a signal based thereon in synchronism with the intermittent illumination.

Abstract: In a photoelectric smoke sensor which produces a fire alarm signal when an amount of attenuation of received light exceeds a predetermined level due to smoke flowing into a space between light emitting and light receiving devices, the level of a receiving light signal from the light receiving device is converted by a converting level control signal. An initial value of the receiving light signal is converted into a digital quantity which is stored in a memory circuit. The digital content of the memory circuit is then converted into an analog quantity. The analog quantity is then compared with the level-converted receiving signal to produce a fire alarm signal. The analog quantity and the level-converted receiving signal are compared with each other at a predetermined period to correct the converting level control signal when there is a difference between the analog quantity and the level-converted receiving signal as a result of the comparison.

Abstract: A print head for a dot printer consisting of electromagnet units for driving a plurality of print wires, wherein the electromagnet unit is formed of a plurality of electromagnets and a plurality of armatures which are all assembled into a single magnetic circuit member; and the magnetic circuit member comprises a boss common to the electromagnets, yokes formed of radially arranged arms extending from the boss and parallel arranged arms extending in parallel from the outer ends of the radially arranged arms substantially at right angles thereto, magnetizing pole pieces extending from the intermediate portions of the radially arranged arms in parallel with the parallel arranged arms, and a yoke arm deformation-preventing ring connected to the outer ends of all the parallel arranged arms.

Abstract: A dot printer wire comprising:a smaller diameter forward section provided with a printing portion at the foremost end;a base section having a larger diameter than said smaller diameter forward section; andan intermediate section which lies between said forward and base sections and whose diameter progressively increases from said smaller diameter forward section to the larger diameter base section.

Abstract: A detecting circuit is responsive to the change in a physical parameter indicative of a fire such as smoke, heat, flame or the like, and a comparator circuit connected to the detecting circuit produces detection pulses in synchronism with an oscillator circuit when the change in the physical parameter exceeds a predetermined amount. A counter circuit counts the detection pulses and produces an output which triggers a switching circuit when a predetermined number of consecutive detection pulses are counted. When triggered, the switching circuit transmits an alarm signal to an alarm receiving panel. Connected between the counter circuit and the switching circuit is a monostable multivibrator having a time constant which is equal to or smaller than the supply voltage rise time constant of the counter circuit so as to prevent the trigger signal from being applied to the switching circuit during the transition period immediately following the connection of the power source.

Abstract: What is disclosed is a silicone rubber shaft seal and a composition for its preparation which consists of filled, heat curable silicone rubber and acicular platy mineral powders.

Abstract: A self-extinguishing silicone elastomer containing a curable organopolysiloxane, silica filler, platinum, carbon black, TiO.sub.2 and a triazole compound is disclosed.