| 摘要 |
<p>A beverage mixing and dispensing valve, or a beverage dispenser including the valve, includes and automatic shut-off features. A user presses a cup or container against a lever (14) on a soft-drink dispenser. The lever closes a switch to activate the opening of a solenoid-operated valve (10). At the same time, a detection circuit is monitored to determine whether overflow of drink or foam has occurred. When drink or foam overflows and bridges a gap between two metal conductors (72) on the lever, resistance is lowered and electricity flows in the detection circuit. The valve then automatically shuts off the flow of beverage. Energy is saved in keeping the valve open using a pulse width modulation (PWM) technique for voltage to the solenoid, rather than using a steady-state voltage.</p> |
