Water sensing apparatus
First Claim
1. A portable, resistive, water sensing apparatus comprising a housing, a circuit for detecting changes in resistance within the housing, an alarm connected to and driven by the circuit, and an elongate sensor, one end of which is secured to the housing and is connected to the circuit, and the other end of which has two exposed contacts, so that the circuit can detect changes in resistance between the exposed contacts to detect the presence of water, which sensor has a rigidity which is sufficient to enable it to maintain a configuration in which it supports the whole weight of the sensor to enable the apparatus to be hung by the sensor and has a flexibility which is sufficient to enable it to be bent manually to a desired configuration.
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Accused Products
Abstract
A water sensing apparatus has a housing and a circuit within the housing. An alarm, e.g. a piezoelectric horn, is driven by the circuit. An elongate sensor is secured to the housing and is connected to the circuit. The other end of the sensor is adapted for sensing the presence of water, to activate the alarm. The sensor is both sufficiently rigid to enable it to maintain a configuration in which the apparatus is hung by the sensor, and is sufficiently flexible to enable it to be bent manually to a desired configuration.
41 Citations
24 Claims
- 1. A portable, resistive, water sensing apparatus comprising a housing, a circuit for detecting changes in resistance within the housing, an alarm connected to and driven by the circuit, and an elongate sensor, one end of which is secured to the housing and is connected to the circuit, and the other end of which has two exposed contacts, so that the circuit can detect changes in resistance between the exposed contacts to detect the presence of water, which sensor has a rigidity which is sufficient to enable it to maintain a configuration in which it supports the whole weight of the sensor to enable the apparatus to be hung by the sensor and has a flexibility which is sufficient to enable it to be bent manually to a desired configuration.
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12. An apparatus as claimed 2, wherein the alarm comprises a piezoelectric horn, and wherein the circuit comprises a DC power supply having one power supply line and another line connected to ground;
- a horn oscillator connected to the piezoelectric horn and the power supply;
a differential amplifier having a sensor lead input connected to one lead of the sensor and a sensor reference input and an output connected to the horn oscillator for controlling the horn oscillator, the other lad of the sensor being connected to the power supply line. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 24)
- a horn oscillator connected to the piezoelectric horn and the power supply;
- 21. A portable, resistive, water sensing apparatus comprising a housing, a circuit within the housing for detecting changes in resistance, an alarm connected to and driven by the circuit, and an elongate sensor, which is of uniform cross-section and which comprises an elongate body formed from an insulating material and having a central portion and two edge portions maintained at a uniform spacing along the length thereof by the central portion, each of the portions extending along substantially all the length of the sensor, and two conductive sensor leads encased in the edge portions, with one ends of the sensor leads connected to the circuit within the housing and the other ends of the sensor leads exposed to water, so that the circuit can detect changes in resistance between said exposed other ends to detect the presence of water, the sensor leads being otherwise covered by said side edge portions, wherein the sensor has a rigidity which is sufficient to enable it to maintain a configuration in which it supports the whole weight of the sensor to enable the apparatus to be hung by the sensor and has a flexibility which is sufficient to enable it to be bent manually to a desired configuration.
Specification