Electronic control device, work vehicle, and input circuit

An electronic control device to be mounted in a work vehicle, the work vehicle including a switch that includes a first terminal and a second terminal to switch between an electrically conducting state and an electrically non-conducting state between the first terminal and the second terminal, the electronic control device comprising:

• an input terminal connected to the second terminal of the switch via an electrically conductive lead;
• an input circuit connected to the input terminal via a signal line;
• and
• a microcontroller to detect whether the switch is in the electrically conducting state or the electrically non-conducting state based on an output signal from the input circuit, and to perform at least one process in accordance with a detected result;
• wherein
• the input circuit includes:
• a first resistor connected to a supply voltage or ground and to the signal line;
• a transient current circuit connected to the supply voltage or ground and to the signal line, the transient current circuit including a second resistor to allow a transient current to flow through the switch when the switch transitions from the electrically non-conducting state to the electrically conducting state;
• and
• an RC low-pass filter circuit that includes a capacitor including a first end connected to the ground and a second end connected to the signal line;
• the transient current circuit further includes a PMOS transistor including a drain connected to the ground;
• the second resistor is connected to the signal line and a source of the PMOS transistor;
• and
• the second end of the capacitor is connected to a gate of the PMOS transistor.

An input circuit to be connected via a signal line to an input terminal of an electronic control device to be mounted in a work vehicle, the work vehicle including a switch that includes a first terminal and a second terminal to switch between an electrically conducting state and an electrically non-conducting state between the first terminal and the second terminal;

• wherein
• the input terminal is connected to the second terminal of the switch via an electrically conductive lead;
• the electronic control device includes a microcontroller to detect whether the switch is in the electrically conducting state or the electrically non-conducting state based on an output signal from the input circuit, and to perform at least one process in accordance with a detected result;
• and
• the input circuit includes:
• a first resistor connected to a supply voltage or ground and to the signal line;
• a transient current circuit connected to the supply voltage or ground and to the signal line, the transient current circuit including a second resistor to allow a transient current to flow through the switch when the switch transitions from the electrically non-conducting state to the electrically conducting state;
• and
• a conversion circuit to convert, based on a reference voltage, an analog voltage signal on an output end of the signal line into a digital signal at a logical high level or low level, and to output the digital signal as the output signal;
• and
• the reference voltage is determined based on a voltage across both ends of the first resistor that occurs because of a leakage current flowing in the first resistor when the switch is in the electrically non-conducting state.