Post by thread:[EE]:: Electrically operated valve

Here's a simple but reportedly effective way of producing a low cost electrically operated valve. He uses a standard hydraulic valve, driven by what he says is an electrically operated pepper mill to provide the actuation. I've not seen such a mill here but an electrically operated coffee grinder would probably do the same job (and just may be what this is)(but probably isn't). An electric battery powered screwdriver would also be suitable. Such have 2 or 3 stages of epicyclic gearboxes to allow a relatively modestly sized electric motor to produce the very substantial torque required to turn screws. Actuation speed will depend on gearing and voltage used. Performance is not mentioned on the web site but in an email to the ARocket list he says: > The 1/4" valve opens, at 50 bar, in 2/10 sec, on 9V. That's reasonably impressive. It may give the potato cannon people some ideas :-) - if they haven't been doing this sort of thing for years without me noticing. Russell _________________ On the site he says: This valve is the most recent I made. It's also the easiest to operate, probably the most reliable, and even though the cheapest. It's a 1/4" BSP hydraulic valve, connected to the mechanism of a cheap electric pepper mill (the kind you can buy at < $5). I made an aluminium frame that holds the two parts together; the torque is transmitted via a custom-made piece also. There is a small on/off switch that stops the motor when it has made a quarter of turn (not visible on the picture, it wasn't installed yet). One can probably replace it with a magnetic position sensor and thus get a throttleable valve. This and a pyro and servo operated vales described here: http://www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion_actuatedvalves.htm Picture here: www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion/electroactuatedvalve.jpg

part 1 2845 bytes content-type:text/plain; (decoded 7bit) I have a need for a cheap electronic water valve for an electronic squirt gun I want to design for my son's tree houses. We have 2 tree houses connected with a swinging rope bridge. I want to design electric squirt guns that shut off after so many seconds of shooting. That way the boys cannot just shoot water at each other all of time. It would be like reloading a real gun, it doesn't just fire all of the time. Irrigation valves for home sprinkler systems won't work as they are too slow in their response. Does anyone have any suggestions here? I might design a pic circuit to handle the on/off timing of the valves. {Original Message removed}

Battery screwdrivers are great because they often have a torque release on them. Cedric {Quote hidden}> On Jul 3, 2007, at 3:31 AM, Russell McMahon wrote: > > Here's a simple but reportedly effective way of producing a low cost > electrically operated valve. > > He uses a standard hydraulic valve, driven by what he says is an > electrically operated pepper mill to provide the actuation. I've not > seen such a mill here but an electrically operated coffee grinder > would probably do the same job (and just may be what this is)(but > probably isn't). > > An electric battery powered screwdriver would also be suitable. Such > have 2 or 3 stages of epicyclic gearboxes to allow a relatively > modestly sized electric motor to produce the very substantial torque > required to turn screws. Actuation speed will depend on gearing and > voltage used. > > Performance is not mentioned on the web site but in an email to the > ARocket list he says: > >> The 1/4" valve opens, at 50 bar, in 2/10 sec, on 9V. > > That's reasonably impressive. > It may give the potato cannon people some ideas :-) - if they haven't > been doing this sort of thing for years without me noticing. > > > Russell > > > > _________________ > > On the site he says: > > This valve is the most recent I made. It's also the easiest to > operate, probably the most reliable, and even though the cheapest. > It's a 1/4" BSP hydraulic valve, connected to the mechanism of a cheap > electric pepper mill (the kind you can buy at < $5). I made an > aluminium frame that holds the two parts together; the torque is > transmitted via a custom-made piece also. There is a small on/off > switch that stops the motor when it has made a quarter of turn (not > visible on the picture, it wasn't installed yet). One can probably > replace it with a magnetic position sensor and thus get a throttleable > valve. > > This and a pyro and servo operated vales described here: > > http://www.student.montefiore.ulg.ac.be/~teney/ > h2o2propulsion_actuatedvalves.htm > > Picture here: > > http://www.student.montefiore.ulg.ac.be/~teney/ > h2o2propulsion/electroactuatedvalve.jpg > --

part 1 670 bytes content-type:text/plain; format=flowed; charset=windows-1250; (decoded 7bit) >I have a need for a cheap electronic water valve for an electronic >squirt > gun I want to design for my son's tree houses. We have 2 tree houses > connected with a swinging rope bridge. > Irrigation valves for home sprinkler systems won't work as they are > too slow > in their response. Define "too slow", or specify a necessary and sufficient set of characteristics. The valve system that this thread refers to sounds like it would work but is probably larger than you want. Solenoid valves from washing machines may suit - you'd no doubt want to use low voltage ones. Russell part 2 35 bytes content-type:text/plain; charset="us-ascii" (decoded 7bit)

part 1 1998 bytes content-type:text/plain; (unknown type 8bit not decoded) {Quote hidden}>-----Original Message----- >From: spam_OUTpiclist-bouncesTakeThisOuTmit.edu [.....piclist-bouncesKILLspam@spam@mit.edu] >On Behalf Of Mike Reid >Sent: 03 July 2007 16:22 >To: 'Microcontroller discussion list - Public.' >Subject: RE: [EE]:: Electrically operated valve - home made idea > > >I have a need for a cheap electronic water valve for an >electronic squirt gun I want to design for my son's tree >houses. We have 2 tree houses connected with a swinging rope bridge. > > >I want to design electric squirt guns that shut off after so >many seconds of shooting. That way the boys cannot just shoot >water at each other all of time. It would be like reloading a >real gun, it doesn't just fire all of the time. > >Irrigation valves for home sprinkler systems won't work as >they are too slow in their response. > >Does anyone have any suggestions here? I might design a pic >circuit to handle the on/off timing of the valves. Why not use a windscreen (US: windshield) washer pump? They can produce plenty of pressure, though flow rate is fairly low, and you won't need to bother with solenoid valves etc. A small 12v gel battery should have plenty of capacity for extended seiges ;) Regards Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. ======================================================================= part 2 35 bytes content-type:text/plain; charset="us-ascii" (decoded 7bit)

On 7/3/07, Russell McMahon <apptechKILLspamparadise.net.nz> wrote: {Quote hidden}> Here's a simple but reportedly effective way of producing a low cost > electrically operated valve. > > He uses a standard hydraulic valve, driven by what he says is an > electrically operated pepper mill to provide the actuation. I've not > seen such a mill here but an electrically operated coffee grinder > would probably do the same job (and just may be what this is)(but > probably isn't). > > An electric battery powered screwdriver would also be suitable. Such > have 2 or 3 stages of epicyclic gearboxes to allow a relatively > modestly sized electric motor to produce the very substantial torque > required to turn screws. Actuation speed will depend on gearing and > voltage used. > > Performance is not mentioned on the web site but in an email to the > ARocket list he says: > > > The 1/4" valve opens, at 50 bar, in 2/10 sec, on 9V. > > That's reasonably impressive. > It may give the potato cannon people some ideas :-) - if they haven't > been doing this sort of thing for years without me noticing. > > > Russell > > > > _________________ > > On the site he says: > > This valve is the most recent I made. It's also the easiest to > operate, probably the most reliable, and even though the cheapest. > It's a 1/4" BSP hydraulic valve, connected to the mechanism of a cheap > electric pepper mill (the kind you can buy at < $5). I made an > aluminium frame that holds the two parts together; the torque is > transmitted via a custom-made piece also. There is a small on/off > switch that stops the motor when it has made a quarter of turn (not > visible on the picture, it wasn't installed yet). One can probably > replace it with a magnetic position sensor and thus get a throttleable > valve. > > This and a pyro and servo operated vales described here: > > http://www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion_actuatedvalves.htm > > Picture here: > > www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion/electroactuatedvalve.jpg > -- Everything is nice, except the original valve which definitely wasn't manufactured for 50 atm. At least on this picture.

>> Here's a simple but reportedly effective way of producing a low >> cost >> electrically operated valve. >> >> >> www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion_actuatedvalves.htm >> >> Picture here: >> >> >> http://www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion/electroactuatedvalve.jpg > Everything is nice, except the original valve which definitely > wasn't > manufactured for 50 atm. At least on this picture. Why do you think that? I'd be interested in your reasoning. The manufacturer's rating for the valve shown in the photo is 50 atmospheres. In practice it would therefore survive to very substantially above that. But, operation at rated pressure is liable to be extremely* safe. Russell * for many but not all values of extremely. :-)

part 1 1542 bytes content-type:text/plain; (decoded 7bit) Speed for this type of application might mean about 1 second to turn on. I will see if I can get a washing machine solenoid. I tried one from a refrigerator ice maker but it is made for much lower pressure. We have 60-90 psi on our outside water so I need to handle a lot of pressure. {Original Message removed} part 2 35 bytes content-type:text/plain; charset="us-ascii" (decoded 7bit)