Abstract: Because a semiconductor relay system of this invention comprises an across-element voltage detecting circuit 116 which delivers an across-element voltage detection signal depending on the presence/absence of an across-element voltage exceeding a predetermined threshold; an element driving circuit 112 for delivering an element driving signal in response to a control input signal; a logic-based judgement circuit 119 for delivering a logic-based judgement signal depending on the presence/absence of an across-element voltage detection signal; and a filtration circuit for removing a logic-based judgement signal of external disturbing elements to produce an element safety check signal, it is possible to reliably detect the disorder of a triac 114.

Abstract: Because a semiconductor relay system of this invention comprises an across-element voltage detecting circuit 116 which delivers an across-element voltage detection signal depending on the presence/absence of an across-element voltage exceeding a predetermined threshold; an element driving circuit 112 for delivering an element driving signal in response to a control input signal; a logic-based judgement circuit 119 for delivering a logic-based judgement signal depending on the presence/absence of an across-element voltage detection signal; and a filtration circuit for removing a logic-based judgement signal of external disturbing elements to produce an element safety check signal, it is possible to reliably detect the disorder of a triac 114.

Abstract: To provide a capacitive sensor which produces a sensor output excellent in linearity. The capacitive sensor comprises a first semiconductor substrate and a second substrate. The first semiconductor substrate is formed with a frame portion and a diaphragm portion serving as a movable electrode, and bonded with the second substrate at the upper surface of the frame portion by anodic bonding. The second substrate is provided with a fixed electrode on a surface facing the diaphragm portion. A fixing projection is provided on a center of the diaphragm portion and is fixed to the second substrate through a hole of the fixed electrode. When external force is applied to the sensor, the diaphragm portion displaces upward and/or downward. The external force is detected based on change of electrostatic capacitance. Since the center of the diaphragm portion is fixed by the fixing projection, the maximum displacement region of the diaphragm portion forms a ring, resulting in enhancement of linearity of the sensor output.