| 摘要 |
A capacitive, operator-sensing circuit for mobile power equipment includes a charge-transfer touch sensor that is electrically coupled to at least one sensing electrode mounted on a gripping surface of the mobile power equipment. The charge-transfer touch sensor is preferably a digital integrated circuit that operates to change an output voltage between two levels or states (logic high and logic low) depending upon a quantity of charge sensed on the at least one sensing electrode, the sensed charge on the at least one sensing electrode changing with the presence or absence of an operator's hand on the at least one sensing electrode. The charge-transfer touch sensor outputs a DC voltage signal, maintaining a given output voltage level until the sensor senses a predetermined change in sensed charge on the sensing electrode. The capacitive operator-sensing circuit additionally includes coupling circuitry coupled between the charge-transfer touch sensor and a component of the equipment. A change in sensor output voltage from a first level to a second level causes a cessation of operation of the component. For example, the component may be an internal combustion engine of the equipment and a change in sensor output voltage from the first level to the second level causes the coupling circuitry to electrically couple a magneto of the engine to be coupled to ground thereby shutting off the engine.
|
