A no-voltage output and voltage output switching circuit (1, 1A, 1C) comprising: an actuator connection terminal block including a plurality of ports (21a, 21b, 21c, 21d) each including a first pin (26a, 26b, 26c, 26d), a second pin (27a, 27b, 27c, 27d), and a third pin (28a, 28b, 28c, 28d) to which an actuator is connected; a power connection terminal block including a voltage terminal and a common terminal to which a power supply is connected; a plurality of first relays (4a, 4b, 4c, 4d,11c); and a plurality of second relays (5a, 5b, 5c, 5d), wherein the voltage terminal is a terminal to which a voltage different from a voltage applied to the common terminal is applied when the power supply is connected to the power connection terminal block, the common terminal is connected to the second pin (27a, 27b, 27c, 27d) of each of the plurality of ports (21a, 21b, 21c, 21d), each of the plurality of first relays (4a, 4b, 4c, 4d, 11c) corresponds to one of the plurality of ports (21a, 21b, 21c, 21d), and each of the plurality of ports (21a, 21b, 21c, 21d) corresponds to one of the plurality of first relays (4a, 4b, 4d, 4d, 11c), each of the plurality of second relays (5a, 5b, 5c, 5d) corresponds to one of the plurality of ports (21a, 21b, 21c, 21d), and each of the plurality of ports (21a, 21b, 21c, 21d) corresponds to one of the plurality of second relays (5a, 5b, 5c, 5d), one of the plurality of first relays (4a, 4b, 4c, 4d) is a first specific relay to enable connection between the first pin of a corresponding port among the plurality of ports (21a, 21b, 21c, 21d) and the third pin of the corresponding port, and the second relay corresponding to a port among the plurality of ports (21a, 21b, 21c, 21d) corresponding to the first specific relay enables connection between the first pin of the port corresponding to the first specific relay and the voltage terminal. an actuator connection terminal block including a plurality of ports (21a, 21b, 21c, 21d) each including a first pin (26a, 26b, 26c, 26d), a second pin (27a, 27b, 27c, 27d), and a third pin (28a, 28b, 28c, 28d) to which an actuator is connected; a power connection terminal block including a voltage terminal and a common terminal to which a power supply is connected; a plurality of first relays (4a, 4b, 4c, 4d,11c); and a plurality of second relays (5a, 5b, 5c, 5d), wherein the voltage terminal is a terminal to which a voltage different from a voltage applied to the common terminal is applied when the power supply is connected to the power connection terminal block, the common terminal is connected to the second pin (27a, 27b, 27c, 27d) of each of the plurality of ports (21a, 21b, 21c, 21d), each of the plurality of first relays (4a, 4b, 4c, 4d, 11c) corresponds to one of the plurality of ports (21a, 21b, 21c, 21d), and each of the plurality of ports (21a, 21b, 21c, 21d) corresponds to one of the plurality of first relays (4a, 4b, 4d, 4d, 11c), each of the plurality of second relays (5a, 5b, 5c, 5d) corresponds to one of the plurality of ports (21a, 21b, 21c, 21d), and each of the plurality of ports (21a, 21b, 21c, 21d) corresponds to one of the plurality of second relays (5a, 5b, 5c, 5d), one of the plurality of first relays (4a, 4b, 4c, 4d) is a first specific relay to enable connection between the first pin of a corresponding port among the plurality of ports (21a, 21b, 21c, 21d) and the third pin of the corresponding port, and the second relay corresponding to a port among the plurality of ports (21a, 21b, 21c, 21d) corresponding to the first specific relay enables connection between the first pin of the port corresponding to the first specific relay and the voltage terminal.