| 摘要 |
PURPOSE:To provide an excellent ventilating fan not requiring a force for opening a shutter, being inexpensive and enabling a small overall size, by a construction wherein a shutter-operating member is provided which is formed of a shape memory alloy undergoing transformation under heat generated by the secondary voltage induced in a transformer coil, and a shutter is opened by the member. CONSTITUTION:With a switch 13 closed, a main winding 3a is supplied with an electric current, and an auximiary winding 3b is supplied with an electric current through a capacitor 3c, whereby a motor 3 is started to rotate vanes 5. On the other hand, the secondary voltage is induced in the transformer coil 15 magnetically connected to the main winding 3a, and the voltage is impressed on the shutter-operating member 10 connected to both ends of the coil 15, so that the member 10 generates Joule heat due to electric resistance thereof, and the member 10 formed of a shape memory alloy undergoes transformation, particularly, shrinkage under the heat. Accordingly, a connecting rod 7 is lowered, and the shutter 2 is opened.
|
