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(PGIP) Use of Human Conduction with Power Tools Disclosure Number: IPCOM000244760D
Publication Date: 2016-Jan-11
Document File: 2 page(s) / 43K

Publishing Venue

The Prior Art Database


A touch sensitive solution to operate power tools on/off functionality providing a means to power off the tool when contact is lost, increasing safety.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 57% of the total text.

Page 01 of 2

(PGIP) Use of Human Conduction with Power Tools

Disclosed is a circuit that provides the means for power tools (or any household powered garden tool) to be powered on/off via human contact. Power tools, for safety reasons should often only be operated when two hands are holding the tool. The act of holding with only one hand is not safe, the level of control the user has over the tool is minimised, and there is a hand free which potentially could get caught in the tools mechanics, therefore the tool should not operate. The act of holding the tool in two designated places switches the tool on, and the act of taking a hand away disables the tool.

Two handles/grips on the tool have a unique conduction pad, when a person

makes contact with each pad (via two hands), a circuit is made, and the conduction of electricity through the human body allows the controller to power on. Taking a hand away means there is now a safety risk, the circuit is broken and the tool is disabled.

Page 02 of 2

    The circuit that makes the touch sensitive functionality possible consists of two transistors in a Darlington Pair, as a switch configuration. The lower most transistor in the circuit takes the low current at its base from the human conduction and amplifies it significantly from it's emitter. We then have a second transistor taking in this amplified current at it's base, and further amplifying it again, providing the current needed to operate the 'Load', which in this case could be th...