Patent ID: 8643360

Claim:
A voltage gradient detector for use in water to detect the presence of a voltage gradient at least as large as a specified critical voltage gradient G MIN , the gradient detector comprising: a first pair of electrodes; a first LED having a known voltage characteristic such that said LED is illuminated when it experiences a set voltage threshold value V T ; a first set of conductors electrically connecting said first LED to said first pair of electrodes such that said first LED experiences a voltage that is directly responsive to the voltage between said electrodes, a spacer that maintains said first pair of electrodes at a separation S along a first axis, wherein S>V T /G MIN ; further wherein said first LED is connected in series with a first LED resistor selected to limit the current through said first LED to an appropriate level to prevent damage to said first LED due to excessive electrical current, and still further wherein the set voltage threshold value V T used to calculate the separation S is calculated by adding the minimum voltage that illuminates said first LED and the voltage drop across said first LED resister that results from the current through said first LED at that minimum voltage; means for electrically isolating from the water said first LED and said first set of conductors attached to said first LED when the voltage gradient detector is in service, whereby said first LED is illuminated when said first pair of electrodes are exposed to a voltage potential therebetween that is at least as great as the threshold value V T , thereby providing a voltage sufficient to illuminate said first LED; and means for providing a notice when said first LED is illuminated.