Signal output device

A signal output device comprising:

• a power supply terminal configured to be connected to a direct current (DC) power supply;
• a ground terminal configured to be grounded;
• an output terminal configured to be connected through a branch path to a voltage dividing point provided in a middle of a main path which is a current path connecting the power supply terminal and the ground terminal, and to transmit an output signal based on a voltage of the voltage dividing point to an outside;
• a signal generation circuit configured to adjust the voltage of the voltage dividing point and to generate the output signal;
• a short circuit detection circuit configured to be provided on at least one of an upper path which is a path between the power supply terminal and the voltage dividing point in the main path, a lower path which is a path between the voltage dividing point and the ground terminal in the main path, and the branch path, and to detect a short circuit between the output terminal and another terminal when a current flowing in the branch path is greater than a short circuit detection threshold that is predetermined;
• and
• a switching circuit configured to switch a current carrying capacity or a configuration of the signal generation circuit to limit a short circuit current flowing in the branch path when the short circuit detection circuit detects the short circuit, wherein
• the short circuit current is set to a value equal to or greater than the short circuit detection threshold and less than a current upper limit value based on a supply capacity of the DC power supply.