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Article #20420Re: Finding an electrically-controlled valve?
From: Knudsen
Date: Mon, 16 Jan 1989 21:44
Date: Mon, 16 Jan 1989 21:44
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1437 bytes
[Water DAC with 4 valves bit-weighted by powers of 2]. Neat idea. I just happen to own a pair of what must be the oldest type of DAC in existence. These are also 4-bitters: 4 square, flat air bellows stacked one atop the other, with adjustable gaps of 1, 2, 4, and 8 16ths of an inch. One end of the bellows stack is fixed and the other output end thus takes positions of 0 thru 15 16ths of an inch in 1/16" steps. This is part of a Duo-Art reproducing player piano, and is used to control the vacuum level, hence piano volume, of the playback. The output rods drive big bellows-type vacuum regulators. Need binary D/A system, invented in 1913! More fun to watch than a CD player, you bet. -- Mike Knudsen Bell Labs(AT&T) att!ihlpl!knudsen "Lawyers are like nuclear bombs and PClones. Nobody likes them, but the other guy's got one, so I better get one too."
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arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!ames!hc!pprg.unm.edu!unmvax!tut.cis.ohio-state.edu!osu-cis!att!ihlpl!knudsenReferences:
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!ames!hc!pprg.unm.edu!unmvax!tut.cis.ohio-state.edu!osu-cis!att!ihlpl!knudsen From: knudsen@ihlpl.ATT.COM (Knudsen) Newsgroups: sci.electronics Subject: Re: Finding an electrically-controlled valve? Summary: Mechanical Air Vacuum DAC Keywords: valves, plumbing, motorized valves Message-ID: <8486@ihlpl.ATT.COM> Date: 16 Jan 89 21:44:50 GMT References: <1404@accelerator.eng.ohio-state.edu> <2925@kitty.UUCP> <1235@ncar.ucar.edu> Organization: AT&T Bell Laboratories - Naperville, Illinois Lines: 19