Abstract: A pulse-controlled circuit for an insulate gate power transistor (Tp) comprises an auxiliary MOS transistor (T1) connected between the gate and a reference terminal of the power transformer in parallel with a pulse transformer secondary (W2). This circuit comprises two controlled unidirectionally conductive paths in parallel (D1, M1; D2, M2) between one terminal of the transformer secondary and the auxiliary transistor gate, these paths being alternatively rendered conductive when a positive or negative pulse is applied to the secondary of the transformer.

Abstract: An integrated circuit self-protected against a reversal of its supply battery polarity comprises a first DMOS power transistor connected with its source electrode side to an electric load to be driven toward ground, and a second, protective DMOS transistor which is connected with its source electrode side to a positive pole of the battery and with its drain electrode side to the drain electrode of the first transistor. The first and second transistors have in common the drain region formed on a single pod in the semiconductor substrate.

Abstract: A protective device for an electric control circuit having first and second input buses to be applied with a source voltage of low level from a commercially available source of electricity and an electrical load of low rating voltage connected between the input buses. The protective device is in the form of a switchover relay disposed between the input buses and the electrical load for maintaining the electrical load in connection to the input buses when applied with the source voltage of low level and for disconnecting the elecrical load from the input buses when applied with a source of high level from the source of electricity. The operating voltage of the switchover relay is determined to be higher than a maximum allowable voltage of the electrical load and to be lower than a lower limit value of the source voltage of high level.

Abstract: A ground-safety controller circuit containing a thyristor that senses grounding of electrical equipment and enables interruption of power to the equipment.

Abstract: A semiconductor circuit has d.c. supply lines (10/13,11/14) and an excess voltage protection circuit. The protection circuit comprises a switching transistor (T1) connected in series with one of the supply lines (10/13) and a control circuit (15) which is responsive to a voltage detector circuit (16) coupled to the one supply line (10/13). The control circuit triggers the switching transistor to a non-conductive state upon detection of an excess voltage. The voltage detector circuit comprises a semiconductor element (T8) having a voltage breakdown characteristic correlated with one or more of the remaining semiconductor elements (T10). The semiconductor element (T8) is adapted to be driven to breakdown in response to a voltage across the supply lines less than that which will cause breakdown of the one or more remaining semiconductor elements T10.

Abstract: An unplugging apparatus includes an electrical sensing circuit for sensing the approach of an electrical storm, and a mechanical actuator for disconnecting a power cord plug from a receptacle in response to a signal from the sensing circuit. The sensing circuit and the mechanical actuator are mounted within a housing. A pull cord extends from the housing and is connected to the power cord plug to disconnect the plug from the receptacle. The other end of the pull cord is connected to a pivotable trigger arm, which pivots to pull the pull cord in response to activation by the sensing circuit. A coil spring biases the trigger arm so as to pull the pull cord, and a latch is operable to retain the trigger arm until actuated by the sensing circuit. A solenid is energized to operate the latch and release the trigger arm, by a signal from the sensing circuit. The sensing circuit includes a detector circuit which receives static produced by lightning in the form of radio waves.

Abstract: An electronic protection device without moving parts uses an automatically-resetting overcurrent protection element, such as positive temperature coefficient device, and keeps its alarm contact terminal constantly in contact with the alarm contact point of a fuse mount. A coil spring is used not to move the alarm terminal but merely to constantly hold the alarm terminal in contact with the alarm point of the fuse mount. A transistor in the electric protection device has its base bias determined by the state of the overcurrent protection element, and has one of its other leads connected to the alarm terminal to generate thereat signals representative of the state of the overcurrent protection element without moving the alarm terminal.

Abstract: Lithium batteries are protected from a runaway condition marked by over-current and high temperature by a temperature sensor having a thermally conductive housing in thermal contact with all the cells of the battery and containing a fusible column which melts when a limit temperature is reached to open a switch in series with the battery. The switch may be the same switch which activates the circuit.

Abstract: An electrical distribution system for factories and offices is assembled from prewired modules. The basic module comprises a section of duct of a standard length with electrical feeder wires mounted therein. The wires are bared of insulation at one end and have connectors at the other to receive the insulation-free wire ends of an adjacent module. Some modules may also include prewired branch circuits with circuit breakers and outlets in a variety of configurations.