Abstract: A water heater pressure relief valve alarm monitors the state of a discharge pipe of a water heater and produces an audible alarm upon detection of water being discharged through the pipe. A clamp with a pipe receiving aperture is removably attached to the pipe. A sensor is positioned adjacent to the pipe receiving aperture. A housing connected to the clamp contains a signal processing circuit, a sound producing device and a battery. The signal processing circuit receives a signal from the sensor and activates the sound producing device upon detection of discharge from the pipe.

Abstract: A water heater pressure relief valve alarm monitors the state of a discharge pipe of a water heater and produces an audible alarm upon detection of water being discharged through the pipe. A clamp with a pipe receiving aperture is removably attached to the pipe. A sensor is positioned adjacent to the pipe receiving aperture. A housing connected to the clamp contains a signal processing circuit, a sound producing device and a battery. The signal processing circuit receives a signal from the sensor and activates the sound producing device upon detection of discharge from the pipe.

Abstract: A battery charger is described for one or more rechargeable batteries. The charger derives its power from a DC power source such as another battery, and produces a pulsed recharging current that has a periodic variable frequency pulse. The charger also permits higher voltage charging current to be achieved than the initial voltage of the DC power source, and monitors both the power source and the batteries being recharged to avoid depletion of the power source or over charging of the batteries.