Abstract: A fluxgate excitation circuit comprises an excitation inductor having a resistance Rsat and an inductance Lsat. Vin is provided by a half bridge converter of MOSFET switches (S1, S2). The excitation inductor is driven so that it enters saturation at the transition as the excitation cycle passes from positive to negative. Thus, a high input rms current value of the excitation circuit can be achieved. Because the excitation inductor is saturated for part of the cycle it may be much smaller than heretofore and have a smaller power supply. Thus, the circuit finds application in small devices.

Abstract: A fluxgate excitation circuit comprises an excitation inductor having a resistance Rsat and an inductance Lsat. Vin is provided by a half bridge converter of MOSFET switches (S1, S2). The excitation inductor is driven so that it enters saturation at the transition as the excitation cycle passes from positive to negative. Thus, a high input rms current value of the excitation circuit can be achieved. Because the excitation inductor is saturated for part of the cycle it may be much smaller than heretofore and have a smaller power supply. Thus, the circuit finds application in small devices.

Abstract: A magnetic component (20) has conductor windings (22a, 22b) surrounded by insulation (21). In addition, the component (20) has a magnetic plate (23a, 23b) on each side. This is applied using conventional PCB process techniques. The magnetic plates enhance the inductance of the component in a manner which may be controlled by setting the configuration of the plates. For example a plate may have a number of isolated sections. Also, the plates on each side may be interconnected by plated through holes to provide a closed core.