| 摘要 |
A heat exchanging ventilator includes DC motors (22, 23), motor driving units (22a, 23a), rotation detecting units (22c, 23c), and current detecting units (22b, 23b) for air supply and air exhaust. The motor driving units (22a, 23a) apply a pulse voltage approximated to a sinusoidal wave to the DC motors (22, 23). The rotation detecting units (22c, 23c) detect the number of rotations of the DC motors (22, 23). The current detecting units (22b, 23b) detect a current value of the DC motors (22, 23). The heat exchanging ventilator further includes an air-volume setting unit (31), and a controlling unit (30). The air-volume setting unit (31) sets a target air volume common for air supply and air exhaust. The controlling unit (30) controls the pulse voltage based on the number of rotations, the current value, and the target air volume. |
