Hi Bob, Do not discuss patents here please !
This is highly contageous and attracts law suits. Without the mentioning of patents the general idea would have come across as well. Kind regards, Bert Timmerman. > -----Original Message----- > From: geda-user-boun...@moria.seul.org > [mailto:geda-user-boun...@moria.seul.org] On Behalf Of Bob Paddock > Sent: Wednesday, April 07, 2010 8:10 PM > To: gEDA user mailing list > Subject: Re: gEDA-user: hydraulic symbols and schematics > > > If you look at some hydraulic schematics, you'll see a rich duality > > between electric and hydraulic circuits. For example, the pressure > > drop across an orifice is analogous to the voltage drop across a > > resistor. Hydraulic power is pressure * flow (i.e. V * I). > > http://www.unusualresearch.com/Pump/bellocq.htm > > US Patent: 1,941,593 01/02/1934 "PUMPING" [This patent is > interesting in that it shows the plumbing equivalent to > resonance circuits, high pass, low pass, and band pass filters.] > > http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&ad jacent=true&locale=en_EP&FT=D&date=19340102&CC=US&NR=1941593A&KC=A > > > _______________________________________________ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
