Patent ID: 6628100
Filing Date: 2003-09-30
Classification: H02P

Abstract:
A control circuit for a reluctance machine having two mutually movable parts and at least one inductive phase winding, the inductance of which depends on the mutual position of the parts; the control circuit comprising:a first terminal and a second terminal for connection to a power source; valves for setting the winding in a drive mode so as to cause a drive current to flow through the winding, the drive current having a certain maximum value; and means for establishing said mutual position in dependence of a measured current value and/or time value; wherein the control circuit includes a current sensor for measurement of a test current when the winding is in a non-drive mode, the current sensor being adapted for measurement of test currents having a second maximum value lower than said certain maximum value; said position establishing means is adapted to establish said mutual position in dependence of said test current; and the control circuit operates to control the valves to prevent currents exceeding said second maximum value from flowing through the current sensor.