On Thu, 11 Oct 2018 at 10:26, John Ferrell wrote: > https://electronics.howstuffworks.com/gadgets/clocks-watches/clock2.htm > > Don't bother with a patent. > > Patents are "a bit more nuanced than that" - for better or worse. In the early 1900's there were English homes that used weights in the tons range that were cranked up by household staff and used to power the new fangle electric lighting systems. Any patents would be well over 100 years old. A single energy-input-person can typically deliver ~~=3D 50 Watts essential= ly continually and ~~=3D 100 Watts for say an hour and need a sit-down and a nice hot cup of tea or few thereafter. To get useful lighting levels even in the drawing room they'd probably have need a number of people supplying the energy OR precharge the system. With say 1 ton/tonne at 3 metres they'd have 3 x 1000 kg x g (~=3D10) =3D = 30 kJ ~=3D 8 Watt hours =3D not much for the desired use. Wind up time, one person, 100 Watts, 100% efficiency assumed. =3D 30,000 J/100W =3D 300 seconds =3D 5 minutes. Say 10 minutes at 50% over= all efficiency. 100 tons would be more useful ! :-(. Russell --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .