Electrothermal actuators with PWM control

In recent years, as an alternative to continuous control with the use of standard analog automation signals (voltage or current), the Pulse Width Modulation (PWM) control was introduced. Although, it is often considered as the equivalent of a continuous control, in practice this continuous control strategy is not feasible with the use of simple electrothermal actuators. The paper presents the investigation results of selected electrothermal actuators operation under ON-OFF and PWM control. It shows clearly that the pulse width modulation for electrothermal actuators results in discontinuous control, which is only a slight modification of the two-point control method.