Abstract: Handheld power tools with kickback detection and methods of detecting a kickback condition of a handheld power tool are disclosed herein. The methods include moving an implement of the handheld power tool within an implement motion plane and in detecting motion of the handheld power tool. The methods also include determining that the kickback condition exists based, at least in part, on the motion of the handheld power tool. In some embodiments, the handheld power tool is a circular saw that includes a user-actuated assembly. The user-actuated assembly includes a motion sensor, a controller, and a motor. The circular saw also includes a workpiece support and a pivot. The motion sensor is configured to detect acceleration along an acceleration detection axis that extends a threshold pivot axis-acceleration axis distance of at most 4 cm from a pivot axis of the pivot.

Abstract: A contact measurement system for measuring a parameter of a contact of a switchgear includes: a first device for measuring an electrical resistance of the contact and mapping the electrical resistance spatially and/or dynamically; a second device for measuring an axial force of the contact and to map the axial force spatially and/or dynamically as a measured axial force; and a third device for measuring a position of the contact. The contact measurement system determines a position-depending force characteristic based on the measured axial force of the contact and the position of the contact. The contact measurement system determines a status of the contact based on a combination of the position-depending force characteristic with the electrical resistance of the contact.

Abstract: A contact measurement system for measuring a parameter of a contact of a switchgear includes: a first device for measuring an electrical resistance of the contact and mapping the electrical resistance spatially and/or dynamically; a second device for measuring an axial force of the contact and to map the axial force spatially and/or dynamically as a measured axial force; and a third device for measuring a position of the contact. The contact measurement system determines a position-depending force characteristic based on the measured axial force of the contact and the position of the contact. The contact measurement system determines a status of the contact based on a combination of the position-depending force characteristic with the electrical resistance of the contact.