Sumitomo Electric Industries, Limited

Sumitomo Wiring Systems, Limited

Autonetworks Technologies, Limited

Keisuke Mase

Yuuki Sugisawa

Shunichi Sawano

Kota Oda

A power supply control apparatus includes: a semiconductor switching element switched with PWM control; a PWM signal output unit outputting a PWM signal; a current circuit outputting a current related to a current flowing through the semiconductor switching element; a filter circuit converting the current that is output from the current circuit to a voltage; an overcurrent protection circuit turning off the semiconductor switching element based on a voltage value of the voltage filtered by the filter circuit; a voltage detection unit detecting the voltage value of the voltage at a timing near an end of a pulse of a PWM signal; a temperature estimation unit estimating, a temperature of an electric wire through which a current flows that also flows through the semiconductor switching element; and an electric wire protection unit turning off the semiconductor switching element based on the temperature estimated by the temperature estimation unit.

Power supply control apparatus having a wire protection unit

A control circuit turns ON or OFF a switch that is provided at a midpoint of a wire. Thus, power supply via the wire is controlled. A current output circuit outputs a current that corresponds to a current flowing through the wire to a resistance circuit. In the resistance circuit, a series circuit of a resistor (R) and a capacitor (C) is connected in parallel to a resistor (R). The control circuit) turns OFF the switch if the end-to-end voltage value of a voltage across both ends of the resistance circuit is larger than or equal to a reference voltage value.

Power supply control apparatus

In a power supply control apparatus, if a switching signal input from a microcomputer to a control circuit instructs switching on of a semiconductor switch, when an input voltage that is input to the drain of the semiconductor switch is higher than or equal to a predetermined voltage, the control circuit drives a charging circuit. The charging circuit charges a capacitor (Cs) via a diode (D). Accordingly, a voltage at the gate of the semiconductor switch taking a potential at the source of the semiconductor switch as a reference becomes higher than or equal to a predetermined voltage, and thus the semiconductor switch is switched on. While driving the charging circuit, the control circuit keeps driving the charging circuit even if the input voltage becomes lower than the predetermined voltage.

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Mie, Japan

Keisuke Mase