초록 ▼

A closed-loop control for sensing the completion of popcorn popping in a microwave oven and automatically shutting down the oven. A microphone type sensor is acoustically coupled to the microwave oven cavity and provides an electrical signal to an amplifier and filter. The amplified and filtered sig

A closed-loop control for sensing the completion of popcorn popping in a microwave oven and automatically shutting down the oven. A microphone type sensor is acoustically coupled to the microwave oven cavity and provides an electrical signal to an amplifier and filter. The amplified and filtered signal is processed by a pop detector which includes an integrator and shut-down command generator responsive to a decreasing rate of popping to shut the oven off. The integrator provides a pre-pop timer function to maintain the oven on until popping commences. In an alternative sensor embodiment, a piezolelectric type sensor is used. In an alternative pop detector embodiment an adaptive threshold comparator which automatically adjusts pop detector operation to discriminate the popping signal from ambient noise present in the oven.

대표청구항 ▼

The combination of a sensor and improved pop detector for an electronic control for popping corn in a microwave cavity of a microwave oven comprising: (a) sensor means for monitoring the accoustic energy in the microwave oven cavity and for providing an output signal representative thereof; b) means

The combination of a sensor and improved pop detector for an electronic control for popping corn in a microwave cavity of a microwave oven comprising: (a) sensor means for monitoring the accoustic energy in the microwave oven cavity and for providing an output signal representative thereof; b) means for determining a scaled value of ambient noise for the oven from the sensor output signal; and c) ambient noise rejection means for adaptively rejecting the determined ambient noise from the sensor output signal and providing a pop signal representative of the popping of popcorn in the microwave oven cavity.