borgstrm@icarus.eng.ohio-state.edu (Tom Borgstrom) (01/12/89)
I'm trying to find a source of motorized valves for use in an residential water system. The valves would be used to control hot and cold water to a faucet or shower and thus can't be the solenoid type. I would like an inexpensive model that runs off 24 VDC or less and possibly has a built-in valve-position encoder. I've found one model in an industrial catalog (McMaster-Carr) -- this one was designed to withstand boiling sulferic acid, runs off 120 VAC, and costs about $500. Not exactly what I'm looking for 8). Can anyone point me in the right direction -- i.e. with the name of another catalog or manufacturer that might have what I'm looking for? -Tom -=- Tom Borgstrom |borgstrm@icarus.eng.ohio-state.edu The Ohio State University|...!osu-cis!tut!icarus.eng.ohio-state.edu!borgstrm 2015 Neil Avenue | Columbus, Ohio 43210 |
larry@kitty.UUCP (Larry Lippman) (01/13/89)
In article <1404@accelerator.eng.ohio-state.edu>, borgstrm@icarus.eng.ohio-state.edu (Tom Borgstrom) writes: > I'm trying to find a source of motorized valves for use in an residential > water system. The valves would be used to control hot and cold water to a > faucet or shower and thus can't be the solenoid type. I would like an > inexpensive model that runs off 24 VDC or less and possibly has a built-in > valve-position encoder. Try an appliance parts store, usually listed in the Yellow Pages as "Appliances - Household - Major, Parts and Supplies". Consider getting a hot/cold water control valve for a washing machine or dishwasher. Be prepared for the counterperson to ask you for the make and model number of the "machine you are trying to repair"; if you persevere, however, you can probably talk them into finding you a suitable part. This type of valve will invariably be 120 VAC; operating this walve using an SCR or triac - optically isolated if required - should not be a problem. With some care, you can often operate a 120 VAC solenoid valve from 12 to 24 volts DC; be sure to try this empirically to make certain that the valve does not overheat, and that it does in fact operate reliably. W. W. Grainger also stocks these valves at a decent price; however, they are wholesale only and usually refuse to sell to an individual without an established account. So, find a friend with a compny who does business with them. Since the above are all solenoid valves, a position encoder is not required. However, if you wish to make the valve memory non-volatile in case of power failure, you will need a rotary valve. :-) <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {att|hplabs|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
parker@epiwrl.EPI.COM (Alan Parker) (01/13/89)
How about the electric valve that dishwashers use? They don't have position encoders, but they should be readily available.
cook@stout.ucar.edu (Forrest Cook) (01/14/89)
In article <2925@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes: >In article <1404@accelerator.eng.ohio-state.edu>, borgstrm@icarus.eng.ohio-state.edu (Tom Borgstrom) writes: >> I'm trying to find a source of motorized valves for use in an residential >> water system. The valves would be used to control hot and cold water to a >> faucet or shower and thus can't be the solenoid type. I would like an ... >Consider getting a hot/cold water control valve for a washing machine or >dishwasher. ... Try a Water DAC: If you wanted a variable temperature/pressure system, say 4 bits, you could use a 1 to 4 Y manifold, 4 solenoid valves, each with its own pressure setting manual valve or flow restrictor, and a 4 to 1 Y manifold combiner and make an H20 D to A converter with 16 settings. The manual valves/flow restrictors could be set for 1/2, 1/4, 1/8, and 1/16 of full pressure, and the solenoids could be driven via solid state relays for a logic level interface. You could use 4 bits for hot, and 4 for cold and control the whole gizmo with one byte. Some kind of temperature sensor would be nice to complete the loop so that you could get better regulation. ^ Forrest Cook (The preceding comments were my Opinions) ^ /|\ cook@stout.ucar.edu /|\ /|\ {husc6 | rutgers | ames | gatech}!ncar!stout!cook /|\ /|\ {uunet | ucbvax | allegra | cbosgd}!nbires!ncar!stout!cook /|\
paul@hpldola.HP.COM (Paul Bame) (01/14/89)
Would eletric water-sprinkler valves work?
henry@utzoo.uucp (Henry Spencer) (01/15/89)
In article <2925@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes: > Since the above are all solenoid valves, a position encoder is >not required... Unless, of course, you want to be sure that the valve has really operated when you ask it to, which is usually considered necessary in critical control systems. (If you don't think controlling a shower justifies this degree of reliability, consider the consequences of turning off cold but not hot in a place with an enthusiastic water heater -- non-trivial injury might result.) I think the original poster wanted proportional control rather than just on/off, which is why he specified that solenoid valves weren't of interest. Short of the (plausible) suggestion of building a 4-bit hydraulic DAC with four valves, it looks to me like he's going to need something like a motor-controlled needle valve, not normally a consumer item, except perhaps in some fancy washing machine. He'll also need a separate shutoff valve, since needle valves aren't usually designed to reduce flow to zero. -- "God willing, we will return." | Henry Spencer at U of Toronto Zoology -Eugene Cernan, the Moon, 1972 | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
mcmiller@uokmax.UUCP (Michael C Miller) (01/15/89)
You might also try hardware stores that sell parts for automatic sprinkler systems. The valves work at 12v and close in the event of loss of power. As i remember they aren't too pricey and they are durable.I've seen some used in a darkroom for auto-filling chemical trays ( developer , fix and such ). -- < sans => mcmiller@uokmax.UUCP or mcmiller@uokmax.ecn.uoknor.edu > < Abe said 'where you want this killin' done ?' > < God said ' out on highway 61 ' >
torkil@psivax.UUCP (Torkil Hammer) (01/17/89)
In article <10960011@hpldola.HP.COM> paul@hpldola.HP.COM (Paul Bame) writes:
#Would eletric water-sprinkler valves work?
Only for cold water.
Be careful not to do something stupid and illegal here :-)
A hobby project involving automatic residential water valves can easily
turn into a project of filling the whole house with hot or cold
water, at or without a push on a button.
Have fun and don't come home too late.
Don't get yourself in hot water, either.
torkilbrianr@tekig5.PEN.TEK.COM (Brian Rhodefer) (01/17/89)
For the specific application of controlling the temperature of dispensed water (eg in a shower), if you must have a fancy controller, why not consider an in-line water heater? The temperature control problem then changes from one of moving a mechanical valve (ugh! moving parts!) to one of simple multi-kilowatt power control, which is decidedly more up the alley of us sci.electronics types. Unconventionally, Brian Rhodefer ...!tektronix!tekig5!brianr
knudsen@ihlpl.ATT.COM (Knudsen) (01/17/89)
[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."
larry@kitty.UUCP (Larry Lippman) (01/17/89)
In article <1989Jan15.035721.14156@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > > Since the above are all solenoid valves, a position encoder is > >not required... > > Unless, of course, you want to be sure that the valve has really > operated when you ask it to, which is usually considered necessary > in critical control systems. (If you don't think controlling a > shower justifies this degree of reliability, consider the consequences > of turning off cold but not hot in a place with an enthusiastic water > heater -- non-trivial injury might result.) A "reliable" system design would still never trust the valve (and consequently its position) - it would measure the actual temperature of the mixed water, which is ultimately the bottom line. > I think the original poster wanted proportional control rather than just > on/off, which is why he specified that solenoid valves weren't of interest. > Short of the (plausible) suggestion of building a 4-bit hydraulic DAC with > four valves, it looks to me like he's going to need something like a > motor-controlled needle valve, not normally a consumer item, except perhaps > in some fancy washing machine. He'll also need a separate shutoff valve, > since needle valves aren't usually designed to reduce flow to zero. Needle valves are available for process control use which have an effective shutoff position. From an idealistic standpoint, a rotary valve is a poor choice for proportional control applications, since by its very nature the ON<->OFF transition is only 90 degrees of rotation. An example of a suitable valve is a bellows-type valve which uses, in effect, a needle and seat arrangement; the position of the bellows can be controlled via an electric motor drive, electromagnet (for small valves, at least), or air pressure supplied by an I/P transducer (common in industrial applications). One _can_ achieve decent proportional control with just a hot and cold water solenoid valve. In our darkroom, we have a Wing-Lynch electronic water temperature controller which uses two solenoid valves; this unit provides an accuracy of +/- 0.1 deg F. The electronic circuit monitors output temperature and _pulses_ the valves accordingly. The key to effective control in this arrangement is to have a mixing chamber (can be just a coiled length of tubing) to mix the hot and cold water BEFORE the output temperature is measured. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {att|hplabs|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
ciciora@tramp.Colorado.EDU (Ciciora; Steven joseph) (01/18/89)
What about a stepper motor smushing a radaitor hose? Use a hose that can withstand high temp. sjc
knudsen@ihlpl.ATT.COM (Knudsen) (01/19/89)
In article <2936@kitty.UUCP>, larry@kitty.UUCP (Larry Lippman) writes: > The key to effective > control in this arrangement is to have a mixing chamber (can be just a coiled > length of tubing) to mix the hot and cold water BEFORE the output temperature > is measured. You also should equip air chambers (like on old steam fire engines) to filter out the puslations on both sides of the pulsed valves. Otherwise the water ahmmer effects may be terrific. If you hit the resonant frequency of your house plumbing, your sump pump better be in good shape. -- 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."
craig@hp-lsd.HP.COM (Craig McCluskey) (01/19/89)
> What about a stepper motor smushing a radaitor hose? Use a hose that > can withstand high temp. Clever idea. Sort of a peristaltic pump turned into a valve. Craig McCluskey