Patent ID: 7034552
Filing Date: 2006-04-25
Classification: H03K

Abstract:
1. An operator-sensing circuit in a calibrated operator sensing system, said circuit comprising: a) microcontroller means electrically connected for sending commands to a charge-transfer sensor electrically connected for sending sensor charge signals to capacitive means, and receiving raw output capacitive electrode discharge data signals from said capacitive means; b) upon command by said microcontroller means, said charge-transfer sensor sends a sensor charge signal to said capacitive means having a capacitive hand-sensing electrode disposed on a hand-gripping surface of a unit of power equipment and receives a discharge output signal from the hand-sensing electrode and sends a raw discharge output signal to said microcontroller means electrically connected for disabling the motor of a unit of power equipment upon the absence of an operator's hand on a hand-gripping surface of the equipment; c) said capacitive means having an electrical characteristic for operating within a predetermined output capacitor discharge range that includes preselected binary digit values that designate hands-off and hands-on conditions on the hand-gripping surface; d) said capacitor discharge range is effective to distinguish between the presence of an operator's hand and foreign material on the gripping surface for avoiding a false hands-on signal.