| 摘要 |
PURPOSE:To control the speed of a motor driven fan with a simple structure and to instruct the speed control state by connecting a lamp forming a photoelectric switch in parallel with the circuit of the fan. CONSTITUTION:When a body switch 7 is closed by a switch pedal, a switch S3 is simultaneously closed to fire a lamp L3, a motor driven fan 6 is loaded with control circuits R1, R2, and rotates at a low speed. When a switch S2 is closed, a lamp L2 is fired, an element F2 becomes ON in response to the firing, a control circuit R2 is bypassed, and the fan 6 is rotated only at the middle speed of the load of the control circuit R1. When a switch S1 is further closed, the lamp L1 is lit, the element F1 becomes ON, and the motor 6 is rotated at a high speed. |
