Single coil actuator for low and medium voltage applications

A single coil actuator for low and medium voltage applications comprising:

• a single coil electromagnet and a power and control unit operatively connected to said single coil electromagnet,
• said power and control unit comprising:
• a first control unit and a second control unit;
• a power input operatively connected to an input filter and rectifier;
• a power supply operatively connected to said input filter and rectifier and to said first and second control unit;
• a power circuit operatively connected to said single coil electromagnet;
• said first control unit being a microcontroller including analogue and digital inputs and outputs, said second control unit being a PWM controller which controls the current flowing in the single coil electromagnet through said power circuit,
• wherein said first control unit is operatively connected to said second control unit through a first output for setting the current flowing in said single coil electromagnet,
• wherein a second input of said first control unit is operatively connected to an output of said second control unit for measuring the output duty cycle of said PWM controller,
• wherein said first control unit is capable of calculating a change in the impedance in said single coil electromagnet on the basis of the measure of the output duty cycle of said PWM controller.