Actuator for use in valve, has strand comprising series circuit from shape memory alloy wire and switch, where switch loads alloy wire with current from current source in closed condition, and alloy wire is arranged in strand

摘要

The actuator (4) has a shape memory alloy wire (12) attached to an adjusting element (5), which controls a valve opening (3). A series circuit is connected between a supply voltage path and a ground path, and comprises a current source and a parallel circuit that has parallel strands. Each strand has a series circuit from the shape memory alloy wire and a switch i.e. switching transistor. The switch loads the alloy wire with current from the current source in a closed condition, where the alloy wire is arranged in the strand.