Abstract: The Tension Loss/Frequency Comparison Device is a simple and convenient way to determine, within a few hundred pulses, if two independent frequencies are identical in pulses per second. One frequency is essentially a controlled frequency; the other frequency is a randomly occurring frequency, such as the natural frequency of a taut string when it is excited, to be compared, in pulses per second, within a given time frame, to the controlled frequency. If the two frequencies are equal in time, a light is briefly turned on. The controlled frequency is continuously converted to a value representing the tension in a taut string, and displayed on an LCD; the frequency to be compared is the detected and amplified natural frequency of the taut string under test. If the light turns on, shortly after the taut string is excited, indicating an agreement in frequencies, the value shown on the LCD represents the tension in the taut string.

Abstract: The boat sinking warning device is hermetically sealed box, to be permanently installed in the bilge area of a boat, to give an audio frequency or radio frequency warning if a boat is leaking. It comprises two externally exposed conductive terminals, and an electronic circuit to sense the presence of water across these terminals and thereby continually sound an audio alarm or radiate a radio-frequency signal to a remote facility.