Anden Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Denso Electronics Corporation

Kazunori Ozawa

Fukuo Ishikawa

Shinji Oshita

Kenichi Takayoshi

Nobutomo Takagi

Akira Sugiura

Shigekazu Sugimoto

Yukiko Matsubara

Takeshi Hattori

Koichi Watanabe

Yoshimitsu Ukai

A load control device includes a power supply terminal connected to a power source via a fuse, a load driver configured to drive loads by electric power supplied from the power source via the fuse and the power supply terminal, a current detector configured to detect load currents that flow through the loads, respectively, and a controller. The controller is configured to calculate a total current that flows through the fuse based on the load currents detected by the current detector, calculate a physical quantity correlating with the total current and related to a connecting member that connects between the fuse and the power supply terminal in response to that the total current is equal to or higher than a predetermined current value, and limit at least one of the load currents in response to that the physical quantity is equal to or greater than a reference value.

Load control device to be connected to power supply via connecting member and fuse

An overcurrent protection apparatus that protects, from overcurrent, a load circuit including an electric load and wiring electrically connected with each other is provided. The overcurrent protection apparatus includes: a semiconductor switching element that is configured to control energization to the load circuit; and a breaker that stops the semiconductor switching element upon detection of abnormality of overheat or overcurrent at the semiconductor switching element, the breaker having a latch operation mode of continuously stopping the semiconductor switching element even upon cancellation of abnormality detection, and a retry operation mode of canceling stoppage of the semiconductor switching element upon the cancellation of the abnormality detection. The breaker is configured to initially operate in the latch operation mode upon the abnormality detection, and then be switched to the retry operation mode after satisfaction of a predetermined condition.

Overcurrent protection apparatus

An overcurrent protection circuit includes a load drive portion that drives a load based on a power supply voltage; a wire that connects the load and the load drive portion; a current detection portion that detects a load current showing a value of a current flowing through the load; a voltage detection portion; and a controller that controls the load drive portion to control a drive of the load, the controller determining an addition-and-subtraction value, controlling the load drive portion to cut off the load current, and stopping driving the load to protect a protection target from an overcurrent. The controller subtracts the integration value based on an elapsed time after cutoff of the load current. The controller controls the load drive portion to again start to drive the load, and also calculates a post-correction integration value lower than a pre-correction integration value by correcting the pre-correction integration value.

Overcurrent protection circuit

An electric current detection circuit for detecting an electric current flowing to a load includes a voltage generation circuit, a plurality of comparators, and a reference voltage shift circuit. The voltage generation circuit includes a plurality of resistors coupled in series and generates different voltages by dividing a reference voltage with the resistors. The comparators determine a current level of the electric current flowing to the load using the voltages generated by the voltage generation circuit as threshold values. The reference voltage shift circuit shifts the reference voltage. The electric current flowing to the load is detected based on the current level determined by the plurality of comparators before shifting the reference voltage and the current level determined by the plurality of comparators after shifting the reference voltage.

Electric current detection circuit

A first overcurrent detecting circuit outputs a first time-up signal when a time period, in which an electric current flowing into the wire harness is greater than the first threshold, reaches a first duration time, which corresponds to a first threshold. A second overcurrent detecting circuit outputs a second time-up signal when a time period, in which an electric current flowing into the wire harness is greater than the second threshold, reaches a second duration time, which corresponds to a second threshold. The second threshold is less than the first threshold. The second duration time is longer than the first duration time. A determination circuit determines that an overcurrent flows into the wire harness and cause a control circuit to deactivate the switching element when inputting at least one of the first and second time-up signals.

Switch circuit having overcurrent detection function

A load driving semiconductor apparatus includes: a driving transistor, which operates based on an input voltage from an external circuit; a power semiconductor device controlling power supply to a load in such a manner that the power semiconductor device supplies electric power to the load when the transistor operates, and the power semiconductor device stops supplying electric power to the load when the transistor stops operating; and a mounting board, on which the driving transistor and the power semiconductor device are mounted. The mounting board includes a heat radiation pattern for emitting heat generated in the power semiconductor device. The heat radiation pattern includes a heat receiving pattern, on which the driving transistor is mounted.

Growing community of inventors

Anjo, Japan

Kazunori Ozawa