Abstract: An adaptive defrost control system of the present invention monitors an amount of current flowing through the defrost heater to calculate the amount of power delivered thereby. The circuit utilizes a thermistor to monitor the temperature rise of the electrical trace supplying current to the defrost heater to allow the controller to calculate an amount of power delivered thereby. A second thermistor may be used to compensate for a change in ambient temperature that might otherwise be attributed to a change in current flow through the power trace. A physical modification to the power trace to enhance the temperature rise characteristic at the point of placement of the thermistor enhances the accuracy of the calculation. A secondary current flow path around the branch of thermistor placement is also provided so as to not reduce the total current carrying capacity of the power trace.

Abstract: A wireless tank level monitoring system is provided. The system includes a transmitter that is located in close proximity to the storage tank. The transmitter is coupled to a remote-ready tank level gauge, which provides a ratio-metric voltage output proportional to the liquid volume inside the tank. The transmitter periodically monitors the output from the level gauge and transmits the information to a base station located remotely from the storage tank. The base station displays the tank level numerically in percent full, graphically with a bar chart, or both. A conspicuous visual indication is provided by the base station when the tank level drops below a predetermined set point. In battery powered applications, the base station also reads and provides a visual indication of a low battery condition for both the transmitter and base station.