Strain detection device with reduced number of wires

A detection device comprising:

• a bridge circuit including a first node to which a second end of a first reference resistance element and a first end of a second reference resistance element are connected, a second node to which a second end of the second reference resistance element and a first end of a third reference resistance element are connected, a third node to which a second end of the third reference resistance element and a first end of a strain gauge resistance element are connected, and a fourth node to which a second end of the strain gauge resistance element and a first end of the first reference resistance element are connected;
• a capacitance element provided between the first node and the third node;
• a first switch element provided between the fourth node and a reference power supply line;
• and
• a second switch element provided between the second node and a detection circuit.