Abstract: A switching apparatus includes a DC voltage output unit, a switching element to supply the DC voltage to a load, a power detection unit to detect power supplied from the switching element to the load, a drive unit to control the switching element in PWM manner according to an output from the power detection unit, and a stop unit to stop the PWM control if a value of the DC voltage is lower than a first threshold value. The first threshold value is lower than a minimum operation voltage value of the power detection unit.

Abstract: A high-side driver has a semiconductor element being connected in series in a power supply path extending from a DC power source to a linear solenoid and turned on/off to control a current of the linear solenoid. The high-side driver includes a current detector of a current of the linear solenoid, a controller of the semiconductor element, a state detector of the high-side driver or the linear solenoid and output a state signal, a first transmit buffer to latch and output the state signal, a second transmit buffer to output the state signal without latching the same, and a transmit shift register to convert the state signal into serial data and transmit the serial data to an external device at predetermined timing. The state detector selects at least one of the first and second transmit buffers and outputs the state signal to the selected one.

Abstract: A load drive apparatus is provided which comprises a switching element 3 connected in series to a DC power source Vcc and an electric load 4, a drive circuit 5 for generating control signals to turn switching element 3 on and off, a thermal detection element 6 for sensing a temperature of switching element 3, an overheat protective circuit 7 for generating an overheat detection signal when thermal detection element 6 senses the temperature of switching element 3 over a predetermined temperature level, and a disconnection detection circuit 11 provided with a current mirror circuit 12 connected between one and the other terminals of thermal detection element 6 for detecting a disconnection in wiring between thermal detection element 6 and overheat protective circuit 7.

Abstract: A switching apparatus includes a DC voltage output unit, a switching element to supply the DC voltage to a load, a power detection unit to detect power supplied from the switching element to the load, a drive unit to control the switching element in PWM manner according to an output from the power detection unit, and a stop unit to stop the PWM control if a value of the DC voltage is lower than a first threshold value. The first threshold value is lower than a minimum operation voltage value of the power detection unit.

Abstract: A high-side driver has a semiconductor element being connected in series in a power supply path extending from a DC power source to a linear solenoid and turned on/off to control a current of the linear solenoid. The high-side driver includes a current detector of a current of the linear solenoid, a controller of the semiconductor element, a state detector of the high-side driver or the linear solenoid and output a state signal, a first transmit buffer to latch and output the state signal, a second transmit buffer to output the state signal without latching the same, and a transmit shift register to convert the state signal into serial data and transmit the serial data to an external device at predetermined timing. The state detector selects at least one of the first and second transmit buffers and outputs the state signal to the selected one.

Abstract: A load drive apparatus is provided which comprises a switching element 3 connected in series to a DC power source Vccand an electric load 4, a drive circuit 5 for generating control signals to turn switching element 3 on and off, a thermal detection element 6 for sensing a temperature of switching element 3, an overheat protective circuit 7 for generating an overheat detection signal when thermal detection element 6 senses the temperature of switching element 3 over a predetermined temperature level, and a disconnection detection circuit 11 provided with a current mirror circuit 12 connected between one and the other terminals of thermal detection element 6 for detecting a disconnection in wiring between thermal detection element 6 and overheat protective circuit 7.

Abstract: A solenoid driving apparatus that drives a solenoid by intermittently supplying an exciting current comprises a first current switching element turned ON and OFF so as to switchably allow and block passage of the exciting current supplied to the solenoid L, a loop current circuit 3 being connected to the first current switching element and passing a loop current caused by stored energy in the solenoid when the supply of the exciting current to the solenoid is stopped by the first current switching element, and a second current switching element being disposed between the solenoid and a junction of the first current switching element and the loop current circuit, and being turned ON and OFF so as to switchably allow and block passage of the exciting current and the loop current.

Abstract: By switching the NMOS (11) on and off, a drive current passes through a solenoid (15). The drive current passes through a conversion circuit (16), and an amplifier circuit (17) outputs a current detection result by amplifying the output voltage of the conversion circuit (16). Because a plurality of resistor elements (161 to 16n) that constitute the conversion circuit (16), together with elements that constitute the amplifier circuit (17) are formed diffused to a semiconductor substrate (100), even if the attribute changes by the conversion circuit (16) generating heat, by the drive current, the amplifier circuit (17) becomes approximately the same temperature, and the attribute changes. Therefore, a highly accurate current detection becomes possible without using components for temperature correction.

Abstract: A solenoid (30) has one end connected to the ground G and the other end connected to an N-MOS transistor (33) which applies current from a battery (31) to the solenoid (30). On the other hand, regenerative current generated when the N-MOS transistor turns off flows from a diode (34) whose anode is connected to the ground, via a resistor (32) to the solenoid (30). Accordingly, without connecting the anode of the diode (34) to the solenoid (30) using a lead line, the solenoid (30) can be driven by current. Moreover, since the current flowing from the battery (31) to the solenoid (30) does not flow to the resistor (32), heating is reduced and a solenoid drive apparatus can be made in an IC.

Abstract: A solenoid drive circuit includes a control circuit which comprises a detector with a resistor for discerning current flow therethrough to produce electric signals that correspond to level of current flow through a solenoid connected to the resistor; an amplifier for amplifying the electric signals from the resistor; and an integrator for integrating the amplified output from the amplifier.

Abstract: A solenoid driving apparatus that drives a solenoid by intermittently supplying an exciting current comprises a first current switching element turned ON and OFF so as to switchably allow and block passage of the exciting current supplied to the solenoid L, a loop current circuit 3 being connected to the first current switching element and passing a loop current caused by stored energy in the solenoid when the supply of the exciting current to the solenoid is stopped by the first current switching element, and a second current switching element being disposed between the solenoid and a junction of the first current switching element and the loop current circuit, and being turned ON and OFF so as to switchably allow and block passage of the exciting current and the loop current.

Abstract: A solenoid drive circuit includes a control circuit 2 which comprises a detector 6 with a resistor 6a for discerning current flow therethrough to produce electric signals that correspond to level of current flow through a solenoid 4 connected to the resistor 6a; an amplifier 7 for amplifying the electric signals from the resistor 6a; and an integrator 8 for integrating the amplified output from the amplifier 7. As integrator 8 is reset each time a PWM controller 3 generates at least one of the successive drive signals S3, an operational comparator 5 receives the latest updated and integrated values S8 of relatively small amount from the integrator 8, easily and promptly compares the updated values S8 from the integrator 8 and an objective current values to produce a deviation of the integrated values S8 from the objective current value, and provides the PWM controller 3 with a command value S5 indicative of the deviation.

Abstract: By switching the NMOS (11) on and off, a drive current passes through a solenoid (15). The drive current passes through a conversion circuit (16), and an amplifier circuit (17) outputs a current detection result by amplifying the output voltage of the conversion circuit (16). Because a plurality of resistor elements (161 to 16n) that constitute the conversion circuit (16), together with elements that constitute the amplifier circuit (17) are formed diffused to a semiconductor substrate (100), even if the attribute changes by the conversion circuit (16) generating heat, by the drive current, the amplifier circuit (17) becomes approximately the same temperature, and the attribute changes. Therefore, a highly accurate current detection becomes possible without using components for temperature correction.

Abstract: A solenoid (30) has one end connected to the ground G and the other end connected to an N-MOS transistor (33) which applies current from a battery (31) to the solenoid (30). On the other hand, regenerative current generated when the N-MOS transistor turns off flows from a diode (34) whose anode is connected to the ground, via a resistor (32) to the solenoid (30). Accordingly, without connecting the anode of the diode (34) to the solenoid (30) using a lead line, the solenoid (30) can be driven by current. Moreover, since the current flowing from the battery (31) to the solenoid (30) does not flow to the resistor (32), heating is reduced and a solenoid drive apparatus can be made in an IC.

Abstract: A motor vehicle electrical system having an engine-driven generator for supplying electrical loads on the vehicle, and a semiconductor switch connected in series with the field winding of the generator for on-off control of its excitation. The generator output voltage is constantly compared with a reference voltage in order to provide a duration modulated pulse signal. During steady-state operation, when the sensed generator voltage develops higher than the reference voltage during each prescribed period of time, the switch is biased on and off by the first duration modulated pulse signal. In the event of an abrupt rise in energy requirement from the loads, when the sensed generator voltage does not grow higher than the reference voltage within the preset time, a second duration modulated pulse signal is applied to the switch in order to make progressively longer the excitation periods of the generator field winding.

Abstract: An apparatus for controlling an AC generator in a vehicle, the AC generator including an exciting coil and driven by an engine to generate an AC output which is rectified and fed to a battery, includes a pilot-lamp switching transistor device constituted by a Darlington-connection of transistors, the pilot-lamp switching transistor device having a base and a collector for turning a pilot lamp on/off, the pilot lamp being fed with a current from the battery through a key switch, a resistor connected between the base and the collector of the pilot-lamp switching transistor, an initial exciting transistor for controlling a current for the initial excitation of the exciting coil by the battery, a voltage detection circuit for detecting a voltage of the battery, and a voltage detection circuit switching transistor for controlling a switching operation of the voltage detection circuit.