Patent ID: 8136356

Claim:
A shape memory alloy actuator system comprising: a shape memory alloy actuator which moves a mobile object installed on a shape memory alloy wire by making the shape memory alloy wire contract by heating by supplying an electric power at a time of heating, and by making the shape memory alloy wire elongate by a bias applying member to which bias is applied, resisting in a direction of contraction at a time of cooling; and a resistance feedback circuit, wherein the resistance feedback circuit includes a detection section which detects a resistance value of the shape memory alloy wire at the time of contraction and elongation of the shape memory alloy actuator, a computing section which carries out a comparison operation of comparing a resistance value obtained from the detection section with a resistance value input by a command section, and calculates a value of an electric current to be applied according to the resistance value which is detected, an output section which outputs to the shape memory alloy actuator the value of the electric current applied which is output from the computing section, a control section which controls the detection section, and the computing section, and the output section, and the resistance feedback circuit further includes a storage section which stores a feedback gain which is calculated in advance, a resistance value which is acquired from the detection section, and a time at which the resistance value is acquired, and the computing section includes a gain setting section which calculates an amount of change in the resistance value in a predetermined time from the resistance value and the time stored in the storage section, and calculates the feedback gain based on the change in the resistance value calculated, and replaces the feedback gain which is calculated in advance.