Abstract: An object is to provide a technique capable of bringing a switching time point of a gate drive condition close to an appropriate switching time point. A semiconductor switching element drive circuit includes a logic circuit that inverts a level of an output signal based on a divided voltage of an output voltage of a semiconductor switching element, and a switching circuit. The switching circuit switches a gate drive condition of the semiconductor switching element during a turn-off operation from a first gate drive condition to a second gate drive condition in which a switching speed is lower than that of the first gate drive condition based on the output signal from the logic circuit.

Abstract: To suppress a malfunction of an overcurrent protection circuit caused by rise of a sense voltage in a mirror period immediately after turn-off of a semiconductor switching element. A semiconductor device includes: a semiconductor switching element; a sense resistor; an overcurrent protection circuit which outputs a control signal for controlling on-drive and off-drive of the semiconductor switching element based on whether a sense voltage exceeds a threshold value; and a diode which clamps the sense voltage. When the sense voltage exceeds the threshold value, the overcurrent protection circuit outputs a signal for off-driving the semiconductor switching element as the control signal.

Abstract: The present invention relates to a control circuit controlling a switching device. The control circuit is a control circuit controlling first and second switching devices which are serially connected between first potential and second potential lower than the first potential and operate in a complementary manner. The control circuit includes a first control circuit controlling the first switching device and a second control circuit controlling the second switching device, and performs variable control of a circuit constant of each of the first and second control circuits based on a temperature of one of the first and second switching devices.

Abstract: Primary-side windings of the transformers (T1,T2,T3) are connected in parallel to each other. A switch (SW) turns on/off primary side currents of the transformers (T1,T2,T3). Each transformer (T1,T2,T3) includes a plurality of secondary-side windings.

Abstract: The present invention relates to a semiconductor device provided with a dead-time generation circuit, the semiconductor device including: first and second status-detection circuits that each have a function of detecting whether first and second switching devices are in turn-off operation to output first and second status signals, respectively, and each have a function of generating a dead time of on-off operation of the corresponding one of the first and second switching devices; a first logic circuit that receives a first on-off command signal instructing the first switching device to be turned on or off, and the second status signal to output a signal allowing the first switching device to be turned on only when the second switching device is not in turn-off operation; and a second logic circuit that receives the first on-off command signal instructing the second switching device to be turned on or off, and the first status signal to output a signal allowing the second switching device to be turned on only

Abstract: The present invention relates to a control circuit controlling a switching device. The control circuit is a control circuit controlling first and second switching devices which are serially connected between first potential and second potential lower than the first potential and operate in a complementary manner. The control circuit includes a first control circuit controlling the first switching device and a second control circuit controlling the second switching device, and performs variable control of a circuit constant of each of the first and second control circuits based on a temperature of one of the first and second switching devices.

Abstract: The present invention relates to a semiconductor device provided with a dead-time generation circuit, the semiconductor device including: first and second status-detection circuits that each have a function of detecting whether first and second switching devices are in turn-off operation to output first and second status signals, respectively, and each have a function of generating a dead time of on-off operation of the corresponding one of the first and second switching devices; a first logic circuit that receives a first on-off command signal instructing the first switching device to be turned on or off, and the second status signal to output a signal allowing the first switching device to be turned on only when the second switching device is not in turn-off operation; and a second logic circuit that receives the first on-off command signal instructing the second switching device to be turned on or off, and the first status signal to output a signal allowing the second switching device to be turned on only

Abstract: To suppress a malfunction of an overcurrent protection circuit caused by rise of a sense voltage in a mirror period immediately after turn-off of a semiconductor switching element. A semiconductor device includes: a semiconductor switching element; a sense resistor; an overcurrent protection circuit which outputs a control signal for controlling on-drive and off-drive of the semiconductor switching element based on whether a sense voltage exceeds a threshold value; and a diode which clamps the sense voltage. When the sense voltage exceeds the threshold value, the overcurrent protection circuit outputs a signal for off-driving the semiconductor switching element as the control signal.

Abstract: Primary-side windings of the transformers (T1,T2,T3) are connected in parallel to each other. A switch (SW) turns on/off primary side currents of the transformers (T1,T2,T3). Each transformer (T1,T2,T3) includes a plurality of secondary-side windings.

Abstract: It is an object of the present invention to provide a buffer circuit that reduces a reverse voltage applied to transistors being a complementary pair during turn-on and turn-off. A buffer circuit is a buffer circuit that turns on and turns off a switching element and includes a drive-side element that has an end connected to a base of a drive transistor and a sink-side element that has an end connected to a base of a sink transistor. The drive-side element and the sink-side element are respectively a drive-side diode and a sink-side diode, or a drive-side capacitor and a sink-side capacitor.

Abstract: A ground working tool comprising a tubular base body with an inner receiving space for receiving a cylindrical core of solid ground material, connector mechanism for connecting the tubular base body with a rotary drive and locking mechanism for locking the core in the receiving space of the tubular base body. The locking mechanism involves at least one locking unit having a guide rail being disposed at an inner side of the tubular base body and arranged with a deviation angle relative to a tangential direction of the tubular base body and the locking unit further comprises at least one locking element, which is moveably mounted on the guide rail between a radially outer releasing position and a radially inner locking position, in which the core is clamped within the receiving space by means of the at least one locking element.

Abstract: A transistor (2) is provided on a semiconductor substrate (8). A temperature detection diode (4) for monitoring temperature of an upper surface of the semiconductor substrate (8) is provided on the semiconductor substrate (8). An external electrode (7) is connected in common to an emitter (E) of the transistor (2) and a cathode (K) of the temperature detection diode (4). Therefore, an external electrode for the cathode (K) of the temperature detection diode (4) can be removed, and thus the device can be reduced in size and improved in terms of ease of assembly.

Abstract: A switching element drive circuit of the present invention outputs a voltage to the switching element by use of a voltage output unit configured as an amplifier circuit having a voltage amplification factor of 1 to drive the switching element. When the switching element is turned on, a turn-on voltage having a value higher than a threshold voltage of the switching element and lower than a value of a voltage of a power supply of the switching element drive circuit is provided to the voltage output unit. After elapse of a turn-on voltage maintenance period, a voltage provided to the voltage output unit is switched by a voltage switching unit to the voltage of the power supply of the switching element drive circuit.

Abstract: It is an object of the present invention to provide a technology capable of reliably suppressing a surge voltage even in a case where noise having a small pulse width is generated. A drive protection circuit that drives and protects a switching element includes a gate driving circuit that drives the switching element in response to a gate driving signal and an overcurrent protection circuit that operates a soft cutoff circuit upon an overcurrent of the switching element, the soft cutoff circuit causing the switching element to transition from ON to OFF at a switching speed slower than that of the gate driving circuit. In the drive protection circuit, in a case where a pulse width of ON of the gate driving signal is less than or equal to a response time of the overcurrent protection circuit, the drive protection circuit operates the soft cutoff circuit to cause the switching element to transition from ON to OFF, regardless of the overcurrent.

Abstract: A transistor (2) is provided on a semiconductor substrate (8). A temperature detection diode (4) for monitoring temperature of an upper surface of the semiconductor substrate (8) is provided on the semiconductor substrate (8). An external electrode (7) is connected in common to an emitter (E) of the transistor (2) and a cathode (K) of the temperature detection diode (4). Therefore, an external electrode for the cathode (K) of the temperature detection diode (4) can be removed, and thus the device can be reduced in size and improved in terms of ease of assembly.

Abstract: It is an object of the present invention to provide a buffer circuit that reduces a reverse voltage applied to transistors being a complementary pair during turn-on and turn-off. A buffer circuit is a buffer circuit that turns on and turns off a switching element and includes a drive-side element that has an end connected to a base of a drive transistor and a sink-side element that has an end connected to a base of a sink transistor. The drive-side element and the sink-side element are respectively a drive-side diode and a sink-side diode, or a drive-side capacitor and a sink-side capacitor.

Abstract: A ground working tool comprising a tubular base body with an inner receiving space for receiving a cylindrical core of solid ground material, connector mechanism for connecting the tubular base body with a rotary drive and locking mechanism for locking the core in the receiving space of the tubular base body. The locking mechanism involves at least one locking unit having a guide rail being disposed at an inner side of the tubular base body and arranged with a deviation angle relative to a tangential direction of the tubular base body and the locking unit further comprises at least one locking element, which is moveably mounted on the guide rail between a radially outer releasing position and a radially inner locking position, in which the core is clamped within the receiving space by means of the at least one locking element.

Abstract: A switching element drive circuit of the present invention outputs a voltage to the switching element by use of a voltage output unit configured as an amplifier circuit having a voltage amplification factor of 1 to drive the switching element. When the switching element is turned on, a turn-on voltage having a value higher than a threshold voltage of the switching element and lower than a value of a voltage of a power supply of the switching element drive circuit is provided to the voltage output unit. After elapse of a turn-on voltage maintenance period, a voltage provided to the voltage output unit is switched by a voltage switching unit to the voltage of the power supply of the switching element drive circuit.

Abstract: It is an object of the present invention to provide a technology capable of reliably suppressing a surge voltage even in a case where noise having a small pulse width is generated. A drive protection circuit that drives and protects a switching element includes a gate driving circuit that drives the switching element in response to a gate driving signal and an overcurrent protection circuit that operates a soft cutoff circuit upon an overcurrent of the switching element, the soft cutoff circuit causing the switching element to transition from ON to OFF at a switching speed slower than that of the gate driving circuit. In the drive protection circuit, in a case where a pulse width of ON of the gate driving signal is less than or equal to a response time of the overcurrent protection circuit, the drive protection circuit operates the soft cutoff circuit to cause the switching element to transition from ON to OFF, regardless of the overcurrent.

Abstract: A semiconductor device includes a sense resistor that converts a sense current flowing through a sense terminal of a switching element to a voltage (sense voltage), and an overcurrent protection circuit that performs a protection operation for the switching element when the sense voltage exceeds a threshold. The overcurrent protection circuit can switch the threshold to a first reference voltage, or to a second reference voltage which is lower than the first reference voltage. The overcurrent protection circuit sets the threshold to the second reference voltage at the time of the switching element being in a steady state, and sets the threshold to the first reference voltage during a mirror period immediately after turning-on of the switching element.