TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: The insulating block includes a base block (11A) and a cover block (11B). The cover block is fastened to the base block. The output terminal is fastened onto the surface of the cover block. A holding chamber is provided between the cover block and the base block. A breaker mechanism is provided in the holding chamber. It includes a movable arm protruding externally outside from the cover block. An externally protruding portion of the movable arm is fastened to a fastening metallic component connected to the output terminal. A buried portion is provided on the surface of the insulating block. The insulating block is inserted in the molded resin portion by filling the buried portion with synthetic resin which forms the molded resin portion. A fastened lead plate (28) connected to a protruded terminal of the battery is provided in the insulating block. The insulating block is provided with a connection opening which opens upwardly of a connection portion of the fastened lead plate. A drawn-out lead plate (29) fastened to a terminal of the battery is fastened to the insulating block. It protrudes from one end of the insulating block. The fore of the protruded part is connected to the terminal of the battery. The drawn-out lead plate connected to the terminal is provided with a bent portion bent in the direction that protrudes from the end face of the terminal at its fore end. The drawn-out lead plate is bent in a U-shape. The insulating block is opposed to a terminal surface which the drawn-out lead plate is fastened to. The insulating block has an insertion recessed portion. The bent portion of the drawn-out lead plate is fitted into the recessed portion. The insulating block is positioned at the prescribed position of the end face of the terminal in the state that the bent portion is inserted into the insertion recessed portion. A temperature sensor is connected to the output terminal. A temperature signal is provided from the output terminal in the state that the breaker mechanism is opened. A stopper for the movable arm which moves to an open position is provided on and protrudes from the interior surface of a holding chamber provided with a breaker mechanism. An electronic component is fastened to the output terminals adjacent to each other by soldering. A notch portion is provided at a corner between each of edges of the connection boundary of the electronic component opposed to each other and each of connection surfaces of the electronic component. The notch portion is filled with resin. An electronic component is fastened to the back surfaces of the output terminals by soldering. An insulating portion for preventing the spread of solder is formed integrally with the insulating block in the periphery of an area where the electronic component is soldered. Width adjustment protruding portions are integrally formed on both sides of the insulating block. The outer width of the outermost parts of the adjustment protruding portions is same as the thickness of the battery.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The base block and the cover block are separately formed of plastic. The insulating block is formed of high melting point plastic which is not deformed at the temperature of soldering. The base block and the cover block are formed of high melting point plastic which is not deformed at the temperature of reflow soldering.