Abstract: A light sensing apparatus for different control systems includes a photosensitive element which generates a light current depending on light incident thereto. A pre-circuit connected to the photosensitive element is operative for generating separate basic signals in response to the light current generated by the photosensitive element. Processing circuits connected to the pre-circuit are active simultaneously for converting the basic signals generated by the pre-circuit into conversion-resultant signals having different forms respectively. The conversion-resultant signals are outputted to the control systems respectively. At least one of the processing circuits may include an oscillation circuit which oscillates at a frequency depending on related one of the basic signals generated by the pre-circuit.

Abstract: A circuit arrangement disposed in a node within a local area network is connected to a communication bus within the local area network. The circuit arrangement includes an input circuit for introducing data from the communication bus into the node. A node state detecting device is operative for detecting whether or not the node is in a stand-by state. A power feed suspending device is operative for suspending power feed to at least part of the input circuit when the node state detecting device detects that the node is in the stand-by state. A power feed restarting device is operative for monitoring a voltage at the communication bus, and restarting the power feed to at least part of the input circuit when the voltage at the communication bus becomes equal to a level indicating reception of data. A protective circuit is operative for protecting the input circuit from an abnormal current which flows from the communication bus.

Abstract: In a receiving device, when a communication signal, which changes between low level and high level, is received via a filter circuit, an occurrence of an edge of the filtered received signal is monitored. Upon detection of the edge, a type of the edge, that is, whether the edge is a leading or trailing edge, is determined. Depending on the type of the edge, one of preset times prestored corresponding to types of the edges, is selected and starts to be measured. When the selected preset time elapses, the filtered received signal is sampled. With this arrangement, even when a filtering time of the filter circuit differs depending on a type of the edge of the communication signal, a constant sampling timing relative to the communication signal can be achieved irrespective of whether the detected edge is the leading or trailing edge.

Abstract: First, second, and third power supply lines are separate from each other. A power supply circuit receives electric power from the first power supply line, and generates a given power supply voltage from the received electric power and outputs the generated power supply voltage to the third power supply line. An electronic circuit is connected to the third power supply line to be activated by the power supply voltage. The electronic circuit has an input section for receiving an input signal from the second power supply line. A protective circuit provided in the electronic circuit leaks a current from the input section of the electronic circuit toward the third power supply line when a voltage of the input signal exceeds the power supply voltage.