A semiconductor device having an input terminal and an output terminal. The semiconductor device includes a power semiconductor element having a first main terminal connected to the output terminal, a second main terminal that is grounded and a gate terminal, and an active clamping circuit including a Zener diode and a diode connected in inverse series between the gate terminal and the first main terminal of the power semiconductor element. The semiconductor device further includes a clamp voltage switching circuit configured to switch a clamp voltage of the active clamping circuit according to a change in a voltage of the output terminal relative to the ground at a time when the power semiconductor element is turned off, the clamp voltage being switched to a first clamp voltage and a second clamp voltage, respectively, when the change in the voltage is not, and is, positive.

The present invention proposes a protection device which has a large rated voltage and a large rated current, which is capable of sufficiently suppressing arc generation during activation, and which is also capable of providing suitable protection against overcurrent due to short circuiting or the like of a main circuit. The protection device of the present invention includes (i) a protection element which includes a first thermal fuse and a resistor, and in which the resistor generates heat as a result of current passing through the resistor when there are abnormalities, and the first thermal fuse is activated due to this heat and interrupts the current, (ii) a PTC element and a second thermal fuse which are electrically connected in parallel to the first thermal fuse and which are electrically connected in series to each other, and (iii) a current fuse which is electrically connected in series to the first thermal fuse.

When a temperature is less than a first threshold, a protection circuit unit executes a normal operation by a pulse width modulation. When the temperature is greater than or equal to the first threshold and is less than a second threshold, the protection circuit unit executes a first heat dissipation suppressing operation that suppresses a self-heating of a switching element. When the temperature is greater than or equal to the second threshold, the protection circuit unit executes a full off operation that terminates the switching element. When the temperature is decreased to be less than the first threshold and to be greater than or equal to a third threshold after the temperature becomes greater than or equal to the second threshold, the protection circuit unit executes a second heat dissipation suppressing operation that suppresses a heat dissipated due to an energization of the switching element.

The present invention relates to an electric motor used in household appliances such as washing machines, comprising a rotor, a stator, more than one winding the diameter and coil number of which are determined according to the desired power and the number of revolutions, more than one terminal to which the winding ends are connected, a connector wherein the terminals are situated, fixed on the stator and which provides the electrical connection between the windings and the external power source and a thermal switch connected in series to the windings, which cuts off the electric current passing therethrough and stops the operation of the electric motor by detecting the increase in the current that occurs due to reasons such as excessive load and mains voltage variability.

A solid-state circuit protector includes a first power semiconductor device having an ON resistance that increases with increasing temperature and a second power semiconductor device connected in parallel with the first power semiconductor device having an ON resistance that decreases with increasing temperature. During times when abnormally high currents are flowing through the solid-state circuit protector, the second power semiconductor is switched ON so that some or all of the current is diverted through it, thus protecting the first power semiconductor device from being damaged due to overheating. The first power semiconductor device is either switched OFF, allowing it to cool in anticipation of a lighter load, or is configured to remain ON so that it shares the burden of carrying the high current with the parallel-connected second power semiconductor device yet operates cooler and at a lower ON resistance since it is not required to pass the full current.

An over-current protection apparatus constituted of: a transistor disposed on a substrate; a first thermal sense device arranged to sense a temperature reflective of a junction temperature of the transistor; a second thermal sense device arranged to sense a temperature reflective of a temperature of a casing surrounding the substrate; and a control circuitry, arranged to alternately: responsive to the sensed temperature by the first thermal sense device and the sensed temperature of the second thermal sense device being indicative that the temperature difference between the transistor junction and the substrate casing is greater than a predetermined value, switch off the transistor; and responsive to the sensed temperature by the first thermal sense device and the sensed temperature by the second thermal sense device being indicative that the temperature difference between the transistor junction and the substrate casing is not greater than the predetermined value, switch on the transistor.

A battery protective circuit including a resistor connected to a switch between a battery and a load through which a first current flows, a first driver to supply the first current to the switch and the resistor, a negative temperature coefficient element having resistance that varies in response to heat of the resistor, a second driver to supply a second current to the negative temperature coefficient element, a short-circuit device to be mechanically deformed by a current, a mechanical switch including a plurality of terminals connected with the battery, the terminals electrically connected with each other by deformation of the short-circuit device, a fuse connected in series between the battery and the mechanical switch, a circuit-changing switch configured to supply the second current to the short-circuit device or to block supply thereof, and a controller to control operations of the first driver, the second driver, and the circuit-changing switch.

Terminal assemblies for power receptacles or switches or other electrical devices include a first terminal holding a first terminal screw and a second terminal adjacent the first terminal and holding a second terminal screw. The terminal assembly also includes a thermal protection plate having longitudinally opposed first and second end portions, the first end portion affixed to the first terminal and the second end portion attached to the second terminal. The thermal protection plate has an electrical conductive contact residing between the first and second end portions, closer to the second end portion than the first end portion. The thermal protection plate has a first material with a first thermal coefficient of expansion overlying or underlying a second material with a second thermal coefficient of expansion with the second thermal coefficient of expansion greater than the first thermal coefficient of expansion.

An electronic switch is connected in series with a load dependent on an input signal. The electronic switch is operated in a first operation mode for a first time period after a signal level of the input signal has changed from an off-level to an on-level. The first operation mode includes driving the electronic switch dependent on a voltage across the load and dependent on a temperature of the electronic switch. The electronic switch is operated in a second operation mode after the first time period. The second operation mode includes driving the electronic switch dependent on the temperature according to a hysteresis curve.

The present invention proposes a protection device which has a large rated voltage and a large rated current, which is capable of sufficiently suppressing arc generation during activation, and which is also capable of providing suitable protection against overcurrent due to short circuiting or the like of a main circuit. The protection device of the present invention includes (i) a protection element which includes a first thermal fuse and a resistor, and in which the resistor generates heat as a result of current passing through the resistor when there are abnormalities, and the first thermal fuse is activated due to this heat and interrupts the current, (ii) a PTC element and a second thermal fuse which are electrically connected in parallel to the first thermal fuse and which are electrically connected in series to each other, and (iii) a current fuse which is electrically connected in series to the first thermal fuse.