ROTATION ANGLE DETECTION DEVICE

PROBLEM TO BE SOLVED: To provide a rotation angle detection device mainly used for rotation angle detection of a brake pedal of a vehicle or the like, which can securely detect a rotation angle and light on and off a stop lamp and the like, with a simple structure.SOLUTION: A rotation angle detection device 27 comprises: multiple magnetic detection elements 18A and 18B provided facing each other at predetermined angle intervals relative to a rotation center of a magnet 16; a first control circuit 19 for performing addition or subtraction of detection signals L1 and L2 from the magnetic detection elements 18A and 18B to detect a rotation angle; a second control circuit 21 which performs division of the detection signals L1 and L2 and after that converts the result to an inverse function to detect the rotation angle of a rotor 12; and a switching circuit 24 for switching which of the first control circuit 19 and the second control circuit 21 is made in operation, according to applied voltage. Thus, the rotation angle detection device 27 which has a simple structure and can securely detect the rotation angle and light on and off a stop lamp and the like can be obtained.