Abstract: A contactless potentiometer includes a shaft and a magnet rotatable together with the shaft and detects a rotational angle of the shaft corresponding to a change in magnetic fields caused by the rotation of the magnet, the magnet being held in a tip end portion of the shaft. The potentiometer includes a cover member attached to a housing at a tip end side of the shaft and arranged to define a closed sensor area between the cover member and the housing, and a circuit board mounted to the cover member at a side of the sensor area in a perpendicular or substantially perpendicular relationship with the shaft. The cover member includes a recess portion arranged on a surface of the cover member facing the circuit board, the recess portion cooperating with the circuit board to define a component-mounting spare space.

Abstract: A heat roller control apparatus having a heat roller for hot melt coating a thin film on a member, a heater for heating the heat roller, temperature detecting member for detecting the surface temperature of the heat roller, temperature control member for controlling the heater according to a temperature detecting signal obtained from the temperature detecting means, and temperature judging member for producing a temperature judging signal for judging the state of the surface temperature of the heat roller according to the temperature detecting signal. The temperature judging member calculates a variation of the surface temperature of the heat roller from the temperature detecting signal every predetermined time and judging the stability of the hot melt coating by the variation of the surface temperature of the heat roller when the temperature detecting signal reaches into a predetermined temperature range.

Abstract: A heat roller control apparatus having a heat roller for hot melt coating a thin film on a member, a heater for heating the heat roller, temperature detecting member for detecting the surface temperature of the heat roller, temperature control member for controlling the heater according to a temperature detecting signal obtained from the temperature detecting means, and temperature judging member for producing a temperature judging signal for judging the state of the surface temperature of the heat roller according to the temperature detecting signal. The temperature judging member calculates a variation of the surface temperature of the heat roller from the temperature detecting signal every predetermined time and judging the stability of the hot melt coating by the variation of the surface temperature of the heat roller when the temperature detecting signal reaches into a predetermined temperature range.

Abstract: A heater control apparatus wherein a voltage level of the power supply is discriminated by an input voltage discrimination circuit, and in case that an input voltage applied by an AC power supply is the lowest level, the heater is excited by a current corresponding to a full-wave of the input voltage. In case that the input voltage applied by an AC power supply is a level other than the lowest level, the heater is excited by a current substantially equal to that in the case of the input voltage of the lowest level. The exciting current control circuit is composed of a bridge diode, a current limiting resistor for limiting a current flow from the AC power supply, a Zener diode for setting an input voltage discrimination standard value for discriminating a level of the input voltage, a photo coupler for generating an input voltage discrimination signal, and an exciting current signal generating circuit for generating an exciting current signal.

Abstract: A head phone is disclosed, which includes a pair of housings, each holding therein an electro-acoustic transducer, a head band being extendable and shrinkable, a pair of supporting members, each being curved in substantially inverse L-shape with each other and supporting at its one end one of the pair of housings, and a pair of pivotally supporting members, each being fixed with one of both ends of the head band and pivotally supporting the other end of one of the pair of supporting members in such a manner that each of the supporting members is rotatable around its lengthwise direction and also rotatable against the extending direction of the head band.