Abstract: Connecting terminals (25a to 25d) are accommodated side by side in a terminal box casing (21). Diodes (30a to 30c) are connected electrically between the respective connecting terminals (25a to 25d). The diodes (30a to 30c) are connected in series via the intermediate terminal mounts (28a, 28b). Partition walls (24) for partitioning diode accommodation spaces (23a to 23c) for at least partly accommodating the diodes (30a to 30c) are formed in the terminal box casing (21).

Abstract: Connecting terminals (25a to 25d) are accommodated side by side in a terminal box casing (21). Diodes (30a to 30c) are connected electrically between the respective connecting terminals (25a to 25d). The diodes (30a to 30c) are connected in series via the intermediate terminal mounts (28a, 28b). Partition walls (24) for partitioning diode accommodation spaces (23a to 23c) for at least partly accommodating the diodes (30a to 30c) are formed in the terminal box casing (21).

Abstract: A withstand voltage-testing apparatus includes a high voltage generator for applying a high voltage to a work, the withstand voltage of which is to be measured. A ground conductor covers the work with an insulating material. A conductor is wound around a current transformer to connect the ground conductor and the ground. A variable resistor is connected with the output terminals of the current transformer. A digital panel meter, which includes a detector, detects a voltage generated by the variable resistor. A warning mechanism displays that work produced by the above is defective when a voltage detected by the detector is higher than a predetermined value.

Abstract: In an apparatus for controlling an air-fuel ratio in an internal combustion engine, a main air-fuel ratio sensor having an element temperature strongly affected by the temperature thereof, a sub air-fuel ration sensor having an element temperature weakly affected by the temperature thereof, and a heater associated with the main air-fuel ratio sensor are provided. The resistance value or electric power of the heater is controlled in accordance with the output of the sub air-fuel ratio sensor.

Abstract: A warning system for an air-fuel ratio control system for a electronic controlled internal combustion engine, where a basic fuel injection amount is corrected by a feedback correction factor determined by a signal from an air-fuel ratio sensor arranged in an exhaust pipe. An amplitude of the feedback correction factor caused by an acceleration of the engine, where the exhaust from cylinders is not completely mixed, is detected, and a warning can be given when the amplitude of the feedback correction factor is larger than a predetermined value. A malfunction in the air-fuel ratio system occurring in one cylinder can be detected. In a double O.sub.2 sensor system, where a sub-feedback loop is provided for correcting the feedback correction factor in accordance with a signal from the second O.sub.