Starter driving semiconductor switch apparatus

A starter driving semiconductor switch apparatus that energizes and de-energizes a starter according to commands from an outside, comprising:

• a plurality of semiconductor switches that are connected in series between a battery serving as a power supply and the starter;
• driving circuits that are provided to the semiconductor switches in a one-to-one correspondence to drive the respective corresponding semiconductor switches;
• a voltage monitor that monitors at least a starter-side voltage of a semiconductor switch closest to the starter in the plurality of semiconductor switches and a voltage between the plurality of semiconductor switches;
• a current monitor that monitors a current flowing into the plurality of semiconductor switches;
• a micro processor that makes a diagnosis on whether the starter is allowed to start and whether there is a failure in the semiconductor switches according to the commands, an output from the voltage monitor, and an output from the current monitor and outputs a diagnosis result to an ECU (Engine Control Unit);
• an energization enable and disable determination circuit that outputs an energization enable and disable signal to the starter depending on whether a predetermined condition is satisfied according to the commands, an output to the micro processor, and an output from the current monitor;
• and
• drive circuits that are provided to the plurality of semiconductor switches in a one-to-one correspondence to drive the respective corresponding semiconductor switches according to an output signal of the micro processor and the energization enable and disable signal.

A starter driving semiconductor switch apparatus that energizes and de-energizes a starter according to commands from an outside, comprising:

• a plurality of semiconductor switches that are connected in series between a battery serving as a power supply and the starter;
• driving circuits that are provided to the semiconductor switches in a one-to-one correspondence to drive the respective corresponding semiconductor switches;
• a voltage monitor that monitors a battery-side voltage of a semiconductor switch closet to the battery in the plurality of semiconductor switches, a starter-side voltage of a semiconductor switch closest to the starter, and a voltage between the plurality of semiconductor switches;
• a micro processor that makes a diagnosis on whether the starter is allowed to start and whether there is a failure in the semiconductor switches according to the commands and an output of the voltage monitor and outputs a diagnosis result to an ECU (Engine Control Unit);
• an energization enable and disable determination circuit that outputs an energization enable and disable signal to the starter according to the commands and an output of the micro processor;
• drive circuits that are provided to the plurality of semiconductor switches in a one-to-one correspondence to drive the respective corresponding semiconductor switches according to an output of the micro processor and the energization enable and disable signal;
• a diagnosis semiconductor switch that is connected between a battery side of the semiconductor switch closest to the battery in the plurality of semiconductor switches and a battery side of the semiconductor switch closest to the starter;
• and
• a drive circuit that brings the diagnosis semiconductor switch together with the semiconductor switch closest to the starter into conduction for a short time by an output of the micro processor when a failure diagnosis is made.

A starter driving semiconductor switch apparatus that energizes and de-energizes a starter according to commands from an outside, comprising:

• a plurality of semiconductor switches that are connected in series between a battery serving as a power supply and the starter;
• a plurality of voltage monitors that respectively monitor a battery-side voltage of a semiconductor switch closest to the battery in the plurality of semiconductor switches, a starter-side voltage of a semiconductor switch closest to the starter, and a voltage between the plurality of semiconductor switches;
• an output circuit that outputs a result of comparison between outputs of the plurality of voltage monitors and a predetermined determination voltage to an ECU (Engine Control Unit) as a failure diagnosis output;
• drive circuits that are provided to the plurality of semiconductor switches in a one-to-one correspondence to drive the respective corresponding semiconductor switches according to the commands;
• a diagnosis semiconductor switch that is connected between a battery side of the semiconductor switch closest to the battery in the plurality of semiconductor switches and a battery side of the semiconductor switch closest to the starter;
• and
• a drive circuit that brings the diagnosis semiconductor switch together with the semiconductor switch closest to the starter into conduction for a short time according to one command from the outside and a diagnosis request signal from the ECU (Engine Control Unit) when a failure is diagnosed.