Abstract: An electromagnetic-noise protection circuit for protecting an electrical device, which processes wanted signals, comprises a sensor which senses the presence of ambient electromagnetic noise from which the electrical device is to be protected, and a filter coupled to the sensor and intermitting the operation of the electrical device in time periods during which the sensor senses the presence of the ambient electromagnetic noise. The sensor can include a discriminator which discriminates wanted signals affected by ambient electromagnetic noise from wanted signals not affected by ambient electromagnetic noise. The discriminator can be implemented as a window comparator comprising at least three triggers and a logical gate and producing a logic output signal indicating if the input signal is either below a certain lower threshold or beyond a certain upper threshold.