US 6,157,303 A · Water safety portable transmitter and receiver

Abstract

The present invention relates to a portable water safety monitoring device including a transmitter to be worn on a person, and a base station for monitoring any transmission from the transmitter indicating immersion of the transmitter in water. The device is particularly applicable for monitoring children near a swimming pool or other body of water to prevent drowning accidents. The transmitter is a compact printed circuit board carrying a capacitance water sensor and a sealed circuitry for detecting a change in capacitance and transmitting an alarm signal to the base station. Advantageously, on opposing sides of the printed circuit board large perimeter conductors provide a sensor able to register a varying level of capacitance. This can reduce false alarms due to incidental wetting. As a further advantage, the use of a compact printed circuit board eliminates any exposed leads in the construction, which could be damaged or disconnected by a child deactivating the monitor. A masked encapsulating sealant protects the circuitry from exposure to water while the sensor remains exposed. The design achieves additional compact efficiency by using one of the perimeter conductors as an antenna for transmitting the signal.

Claims27

Dependent claims

A portable water safety monitoring device for use with a receiving station comprising:

a water sensor comprising a first electrode and a second electrode forming a capacitor, wherein the first and second electrodes are dimensioned to provide a variable capacitance in response to an area of the electrodes exposed to water;
a circuit portion electrically coupled to the water sensor including:
a power source
a control circuit for detecting the capacitance of the water sensor for determining a presence of water;
a transmitter for generating a signal in response to detection by the control circuit of the presence of water for transmission to the receiving station for generating an alarm;
and,
a transmitting antenna for transmitting a signal from the transmitter to the receiving station.

4 more elements

Dependencies are inferred from the claim text.

Water safety portable transmitter and receiver

Life of this patent

Water safety portable transmitter and receiver

Life of this patent

Abstract

Claims27