The non-linear element (22) has a rectifying characteristic, inputs the received electrical signal (7, 17) and provides a rectified signal at its output.

Detection of breathing is performed by low-pass filtering the rectified and filtered signal, and adaptive thresholding of the low-pass filtered signal.

In general, rectifier circuitry receives an AC power signal and generates a rectified signal, which is provided to first and second converter circuitries.

In turn, the fixed portion includes a DC link having at least one capacitor to receive the rectified signal and provide the DC signal to the inverter stage.

Rectifier circuits rectify an incoming signal during discovery mode, and apply the rectified signal to the gate of the relay to improve conductivity of the relay.

The power obtained from the full-wave rectified/smoothed signal is fed to the portions of a semiconductor integrated circuit device (101).

The rectified signal may also be used to control a control electrode of the first transistor of the transmit section in this way.

In order to demodulate an amplitude-modulated signal, two capacitors (C1, C2) are provided to which a signal rectified by a diode (D1) and having a voltage (U1) can be fed.

The MOSFET charges the capacitor while the voltage applied to its gate from the rectified signal is greater than the voltage across the capacitor.

The half-waves of this signal are used by a switch (S3) for alternately charging the first or second capacitor.

In one exemplary embodiment, each of the smaller transducers is coupled to a separate rectifier (230a, 230b, 230c), which rectifies the electrical signal from the respective transducer into a rectified signal.

During the major portion of the a.c. cycle, the full-wave rectified signal follows the low impedance path without loading the current transformer (12) or distorting the current signal.

Just after the enquiry signal starts being received, capacitors are gradually plugged into the useful output until the rectified and smoothed signal takes up a maximum voltage value.

An input a.c. signal is provided to a first terminal of the detector diode, and a rectified signal is provided at the junction of the detector diode, the first resistor, and the capacitor.

A prefilter (220) receives the rectified signal and attenuates high frequency components at frequencies near multiples of a decimation sample rate.