Abstract: A motor-driven alternator including an improved remote on/off switch closure detection system capable of detecting closure of solid-state switches. Such switches are typical of appliances, tools, or other electrical load devices. A sensing signal is provided by a higher voltage ac or pulsating dc signal for overcoming the forward breakdown voltage of semi-conductors typical of such switches. A detection circuit is included which comprises an opto-isolator circuit for isolation of the power and sensing circuits.

Abstract: Apparatus for digitally displaying inclination of a lift truck mast includes an inertial inclination sensor carried by the mast and a digital display module for operator viewing remote from the mast. The inclination sensor includes a disc pendulum pivoted for damping its movement, the disc having a wand extending from it for exaggerated movement about the pivot. A plurality of light responsive devices are provided for detecting the position of the wand for the purpose of determining the degrees of actual mast inclination with respect to a true vertical gravitational plumb line.