Alternating Current Activation of SMAWires

Inhalt:
In most actuator applications, shape memory alloys (SMAs) are activated with an electric current. The required electrical power is usually provided by a direct current (DC) voltage source. This conventional control uses activation times in seconds range. Previous work on DC high voltage activation of SMA wires has shown a potential of energy savings and faster activation times. This work deals with high voltage control of SMA wires, which relies on an alternating current (AC) power supply input. Due to the high energy potential, the wire can not be energized over seconds and the voltage has to be divided into pulses of short duration. The length of each pulse is determinated by a real time energy measurement.