| 摘要 |
PURPOSE:To improve the kinetic characteristics of the operating device to reduce the electric power consumption thereof and permit to prevent overheat of a shape memory alloy by a method wherein a positive characteristic heat sensitive resistance body is arranged in the electric circuit of a heater to heat quickly a driving body consisting of the shape memory alloy. CONSTITUTION:Electric current, which flows to the heater 5, is controlled automatically by the positive characteristic heat sensitive resistance body 7 to control the heating of the driving body 3 consisting of the shape memory alloy. When the driving body 3 is heated and the temperature thereof is increased to the reverse transformation temperature, the current is controlled by the positive characteristic heat sensitive resistance body 7 immediately and a small current is flowed to the heater 5. According to this method, the temperature rise of the driving body 3 due to the heating of the heater 5 may be restricted and the overheat of the driving body may be prevented. Accordingly, a big current can be flowed temporarily to the heater 5, the heating property of the heater 5 can be increased and the improvement of the kinetic characteristic of the operating body 1 as well as the reduction of consumed electric power may be permitted. |
