AIRLINE COFFEE BREWER

摘要

An ultrasonic system for measuring the volume of liquid in a container (65) having a lid (73) in which an ultrasonic signal is emitted and received by a sensor subsystem (64) located on the underside of the lid of the ultrasonic system. The ultrasonic system can measure the exact amount of liquid or the level of the liquid held in the container by processing the roundtrip time t he ultrasonic signals took to travel from the sensor subsystem to the surface o f the liquid where the ultrasonic signals are reflected back to the ultrasonic sensor subsystem. A solid state, three-phase SCR/diode bridge (96) converts a three-phase alternating current (AC) to a direct current (DC) power source f or heating the liquid in a boiler subsystem (57) prior to its transport to the contain er. A second, triac controlled heater (86) is powered by a single phase of the three phase power source, and is used to warm and maintain the liquid held within the container at a constant temperature.