<p>The electromagnetic circuit protector has an input voltage charged with a full wave rectified alternating current or dc voltage. The fuse has a coil and works such that the control to obtain a closed state is achieved with a large pulse width in dependence on an adjustment frequency and the closed state is maintained with a smaller pulse width. The on/off control is carried out at the smaller pulse width. The circuit includes a detector (130, 140) to detect a peak voltage value of the input voltage and an average value of the input voltage. The circuit also includes a regulator (9) to stabilise the input to the coil (120) to a constant level where the pulse width is controlled to a frequency which is adjusted to the base level of the voltage values detected by the detector (130, 140).</p>
