ACTUATOR AND EXHAUST VALVE DRIVING DEVICE

An actuator includes a housing , an output shaft projecting from the inside of the housing to the outside, a motor provided in the housing , a reduction mechanism which connects the motor to the output shaft , a magnet provided for rotation integrally with the output shaft inside the housing , a Hall effect IC disposed to face the magnet outside the rotation locus of the magnet , and a circumferential wall disposed to stand from the inner wall of the housing and interposed between the magnet and the Hall effect IC