| 摘要 |
PURPOSE:To prevent the accumulation of errors as well as to return a mirror to the eye-point accurately by detecting the number of revolutions of a motor constantly and comparing the detected value with a set point for controlling a control circuit automatically. CONSTITUTION:When a switch SWA is pushed, circuits 21A and 24 are on for self-holding. When outputs of circuits 21A, 24, and 5 and and-circuit AND 1 are brought into high levels, as the result, a transistor Tr4 is on to rotate a motor M1 regularly. The number of the revolution is detected by a unit 8, and input into a circuit 4 as pulse signals through a circuit 7 and others. A mirror is changed in the angle to the right hand until the count in the circuit 4 is accorded with the set point in a circuit 3. When the output of AND1 is decreased into a low level, a timer circuit 2 is on to keep the static state of the mirror until the set time is over. Then, when the output of AND2 is brought into a hibh level, a transistor Tr7 is on to rotate the motor M1 reversely, and the mirror is returned to the eye-point. When the count value is accorded with the set point, the motor M1 is stopped automatically. |
