US 10,566,971 B2 · Adaptive proximity sensor

Abstract

A proximity sensor or switch having a sensing coil, an oscillator connected to the coil, a comparator connected to the oscillator, a reference voltage module connected to the comparator, and an output driver connected to the comparator. The voltage module may incorporate a resistor having an end connected to a high side of a power source, and a digital potentiometer having a first end connected to another end of the resistor and to the comparator, and having a second end connected to a ground side of the power source. The digital potentiometer may have a resistance that is varied with a signal. A variation of the resistance for the digital potentiometer may result in a change of a voltage from the reference voltage module which further changes a switching distance of the proximity switch to a predetermined value.

Claims11

Dependent claims

An adaptive proximity detection system comprising:

a sensing coil;
an oscillator connected to the sensing coil;
a comparator connected to the oscillator;
a reference voltage module connected to the comparator;
and
an output driver connected to the comparator;
and
wherein:
the reference voltage module comprises:
a resistor having a first end connected to a high terminal of a voltage source and having a second end;
and
a digital potentiometer having a first end connected to the second end of the resistor and to the comparator, and having a second end connected to a ground terminal of the voltage source;
the digital potentiometer has a resistance that is varied with a signal to the digital potentiometer;
the signal is superimposed on power from the voltage source;
and
the signal is picked off from the power by a demodulator connected to the voltage source.

13 more elements

A dynamically calibrated proximity sensor comprising:

a detector that has an inductance that varies upon a proximity to an inductance-affecting target;
an oscillator connected to the detector, that outputs a signal that has an amplitude that varies with the inductance of the detector;
a comparator connected to the oscillator that compares that amplitude of the signal from the oscillator with a reference voltage;
an output driver connected to the comparator to provide an output to indicate a target proximity;
a resistor network to provide the reference voltage for the comparator;
a high line and a ground line for providing power to the resistor network;
and
a demodulator connected to the high line and the resistor network;
and
wherein:
the resistor network has a resistance that is dynamically varied to adjust the reference voltage to a predetermined value;
and
the resistor network comprises a digital potentiometer that can vary the resistance of the resistor network with a control signal to the digital potentiometer;
the high line is provided a DC superimposed modulated signal by a modulator;
and
the DC superimposed modulated signal is demodulated by the demodulator into the control signal to the digital potentiometer to increase or decrease the resistance of the resistor network.

13 more elements

Dependencies are inferred from the claim text.

Adaptive proximity sensor

Life of this patent

Adaptive proximity sensor

Life of this patent

Abstract

Claims11