Proximity switch, a target, a system of such proximity switches and targets, and a method of determining the presence of a target by a proximity switch
AssigneeJokab Safety AB
InventorsTorgny Olsson, Gunnar Widell, Mats Linger
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Abstract
A proximity switch for detecting a target in proximity with the proximity switch as a wireless transmitter for transmitting a first pulsed signal having a first carrier frequency to the target. The proximity switch also includes a wireless receiver for receiving a second pulsed signal having a second carrier frequency different from the first carrier frequency from the target. The proximity switch has a controller for providing an output indicative of whether a predetermined correspondence is satisfied between the first and second pulsed signals.
Claims16
A proximity switch for detecting a target in proximity with the proximity switch, comprising:
- a wireless transmitter for transmitting a first pulsed signal having the first carrier frequency to the target,
- a wireless receiver for receiving a second pulsed signal generated by a target transmitter having a second carrier frequency different from the first carrier frequency, and
- a controller for providing an output indicative of whether a predetermined correspondence is satisfied between the first and the second pulsed signals.
A target for use in combination with a proximity switch, comprising:
- a wireless receiver for receiving a first pulsed signal having a first carrier frequency from the proximity switch, and
- a wireless transmitter for transmitting a second pulsed signal having a second carrier frequency, different from the first carrier frequency, to the proximity switch, the second pulsed signal being substantially synchronous with the first pulsed signal.
A system of a proximity switch and a target wherein the proximity switch has an input terminal adapted to receive a first signal containing digital information, and a first transmitter for transmitting a second signal, containing said digital information, at a first carrier frequency;
- wherein the target has a first receiver for receiving said second signal and a second transmitter for transmitting a third signal, containing said digital information, at a second carrier frequency, different from said first carrier frequency;
- and
- wherein the proximity switch further comprises a second receiver for receiving said third signal and producing a fourth signal, containing said digital information, to be provided at an output terminal of the proximity switch.
A method of determining the presence of a target by providing a proximity switch, comprising:
- transmitting a first pulsed signal having a first carrier frequency from the proximity switch,
- receiving the first signal in the target,
- transmitting a second pulsed signal having a second carrier frequency, different from the first carrier frequency, from the target,
- receiving the second pulsed signal in the proximity switch, and
- determining that the target is present in response to receiving said second pulsed signal.
Dependencies are inferred from the claim text.