Tilt/Position Sensors
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Posts: 46,084
I'm working on an application where the sensor and electronics is
mounted in the lid of a container. I want to sense when the lid of the
container is off or open so that the device can ignore readings during
this time period. Cost of the sensor/switch is an issue.
My first thought was a mercury type switch like those found in wall
thermostats. Any idea who makes these?
Other options are a reed switch and magnet but the mechanics of making
sure it always aligns properly could be expensive.
Another option is a photo sensor since the inside of the container
would always be dark when the lid is closed. Possible problems could
be dirt blocking the sensor.
I'm open to other suggestions as well.
Tim
mounted in the lid of a container. I want to sense when the lid of the
container is off or open so that the device can ignore readings during
this time period. Cost of the sensor/switch is an issue.
My first thought was a mercury type switch like those found in wall
thermostats. Any idea who makes these?
Other options are a reed switch and magnet but the mechanics of making
sure it always aligns properly could be expensive.
Another option is a photo sensor since the inside of the container
would always be dark when the lid is closed. Possible problems could
be dirt blocking the sensor.
I'm open to other suggestions as well.
Tim
Comments
machines. They work by having a small ball roll within a square enclosure
and depending on the orientation, close contact between a number of
contacts.
I would stay away from mercury switches because eventually your switch
will end up in a land fill or incinerator and mercury is a nasty thing to
release into the environment. Car manufacturers are discontinueing use of
mercury switches to detect truck open/close for this very reason.
Best, Pete.
________________________________________________________
Peter W. Houlihan, (413) 538-3091, phouliha@m...
Mellon Postdoctoral Fellow, Center for Environmental Literacy
Mount Holyoke College, South Hadley, MA 01075
Visit our website at:
http://www.mtholyoke.edu/proj/cel/index.html
________________________________________________________
On Thu, 11 Apr 2002, Tim McDonough wrote:
> Date: Thu, 11 Apr 2002 09:07:50 -0500
> From: Tim McDonough <tim@m...>
> Reply-To: basicstamps@yahoogroups.com
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Tilt/Position Sensors
>
> I'm working on an application where the sensor and electronics is
> mounted in the lid of a container. I want to sense when the lid of the
> container is off or open so that the device can ignore readings during
> this time period. Cost of the sensor/switch is an issue.
>
> My first thought was a mercury type switch like those found in wall
> thermostats. Any idea who makes these?
>
> Other options are a reed switch and magnet but the mechanics of making
> sure it always aligns properly could be expensive.
>
> Another option is a photo sensor since the inside of the container
> would always be dark when the lid is closed. Possible problems could
> be dirt blocking the sensor.
>
> I'm open to other suggestions as well.
>
> Tim
>
>
>
> To UNSUBSCRIBE, just send mail to:
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of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
sure they're cheap, and it sounds like they do exactly what you need. In your
application, it sounds like you really want to measure open/close, not tilt...
Good luck
Clark Hughes
Tim McDonough wrote:
>
> I'm working on an application where the sensor and electronics is
> mounted in the lid of a container. I want to sense when the lid of the
> container is off or open so that the device can ignore readings during
> this time period. Cost of the sensor/switch is an issue.
>
> My first thought was a mercury type switch like those found in wall
> thermostats. Any idea who makes these?
>
> Other options are a reed switch and magnet but the mechanics of making
> sure it always aligns properly could be expensive.
>
> Another option is a photo sensor since the inside of the container
> would always be dark when the lid is closed. Possible problems could
> be dirt blocking the sensor.
>
> I'm open to other suggestions as well.
>
> Tim
>
> If you look hard enough you can find the tilt sensors used in pin
ball
> machines. They work by having a small ball roll within a square
enclosure
> and depending on the orientation, close contact between a number of
> contacts.
Any idea who makes this type of switch? My concern would be cost.
Another option is a photosensor. When the lid is on and the spring
loaded door is closed it's dark inside the container. It will always
be light outside the container any time someone is there to open it
up.
> I would stay away from mercury switches because eventually your
switch
> will end up in a land fill or incinerator and mercury is a nasty
thing to
> release into the environment. Car manufacturers are discontinueing
use of
> mercury switches to detect truck open/close for this very reason.
Good point. It's so early in the project that I hadn't considered any
"end of life" issues.
Tim
> You might also look at door closure switches such as those found in
autos. I'm
> sure they're cheap, and it sounds like they do exactly what you
need. In your
> application, it sounds like you really want to measure open/close,
not tilt...
The application isn't counting the open/close cycles. I need to know
when the container is open so the rest of the system doesn't gather
data during that time.
Tim
sensor mounts in the mailbox. When opened, light hits it and transmits a
signal back to a receiver in the house. Caught the garbage man going
through the neighborhood mailboxes with it.
Mark
Original Message
From: "Tim McDonough" <tim@m...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, April 11, 2002 10:43 AM
Subject: Re: [noparse][[/noparse]basicstamps] Tilt/Position Sensors
> From: "Peter W Houlihan" <phouliha@m...>
> > If you look hard enough you can find the tilt sensors used in pin
> ball
> > machines. They work by having a small ball roll within a square
> enclosure
> > and depending on the orientation, close contact between a number of
> > contacts.
>
> Any idea who makes this type of switch? My concern would be cost.
>
> Another option is a photosensor. When the lid is on and the spring
> loaded door is closed it's dark inside the container. It will always
> be light outside the container any time someone is there to open it
> up.
>
> > I would stay away from mercury switches because eventually your
> switch
> > will end up in a land fill or incinerator and mercury is a nasty
> thing to
> > release into the environment. Car manufacturers are discontinueing
> use of
> > mercury switches to detect truck open/close for this very reason.
>
> Good point. It's so early in the project that I hadn't considered any
> "end of life" issues.
>
> Tim
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>I'm working on an application where the sensor and electronics is
>mounted in the lid of a container. I want to sense when the lid of the
>container is off or open so that the device can ignore readings during
>this time period. Cost of the sensor/switch is an issue.
Use a microswitch with a lever arm?
--
Rgds, Derryck
I didn't imply that you were counting cycles. You want to detect IF the thing
is open or closed, right? That's what the door sensors on cars do. Not sure
why there's confusion on this point... You can measure tilt if you want to, or
you can measure light. Heck, you can measure changes in volume if you can
correlate that to the thing being opened -- knock yourself out. I would use a
switch, but it's a free world (as is this advice).
Tim McDonough wrote:
>
> The application isn't counting the open/close cycles. I need to know
> when the container is open so the rest of the system doesn't gather
> data during that time.
>
> Tim
>
attached to the top adjacent to it. When the top is closed, the magnet
pulls the reed switch in. When the top opens, the reed switch opens too.
Ray
Mark Schmidt wrote:
>
> You might want to hack the MailBox arrival alarm from Radio Shack. The
> sensor mounts in the mailbox. When opened, light hits it and transmits a
> signal back to a receiver in the house. Caught the garbage man going
> through the neighborhood mailboxes with it.
>
> Mark
>
>
Original Message
> From: "Tim McDonough" <tim@m...>
> To: <basicstamps@yahoogroups.com>
> Sent: Thursday, April 11, 2002 10:43 AM
> Subject: Re: [noparse][[/noparse]basicstamps] Tilt/Position Sensors
>
> > From: "Peter W Houlihan" <phouliha@m...>
> > > If you look hard enough you can find the tilt sensors used in pin
> > ball
> > > machines. They work by having a small ball roll within a square
> > enclosure
> > > and depending on the orientation, close contact between a number of
> > > contacts.
> >
> > Any idea who makes this type of switch? My concern would be cost.
> >
> > Another option is a photosensor. When the lid is on and the spring
> > loaded door is closed it's dark inside the container. It will always
> > be light outside the container any time someone is there to open it
> > up.
> >
> > > I would stay away from mercury switches because eventually your
> > switch
> > > will end up in a land fill or incinerator and mercury is a nasty
> > thing to
> > > release into the environment. Car manufacturers are discontinueing
> > use of
> > > mercury switches to detect truck open/close for this very reason.
> >
> > Good point. It's so early in the project that I hadn't considered any
> > "end of life" issues.
> >
> > Tim
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> Tim:
>
> I didn't imply that you were counting cycles. You want to detect IF the
thing
> is open or closed, right? That's what the door sensors on cars do. Not
sure
> why there's confusion on this point... You can measure tilt if you want
to, or
> you can measure light. Heck, you can measure changes in volume if you
can
> correlate that to the thing being opened -- knock yourself out. I would
use a
> switch, but it's a free world (as is this advice).
I wasn't completely sure what you meant and was just trying to clarify my
application in case there was some confusion and for the benefit of others
who might be following this thread. My intent was not to trivialize any
suggestion or dismiss it out of hand.
The container has a hinged door through which material is added. The door
is a part of a larger lid that is completely removed to empty the
container. Sensing tilt or light is attractive because a single sensor,
possibly mounted on the PCB with the rest of the electronics, can detect
both the door open or the lid off. In either case we do not want the device
to measure while the container is "open". We do not need to know which
scenario caused it to open.
For a "one off" system switches would be the obvious choice. They are
simple to use and cheap as you point out. Our application ultimately
involves thousands of containers so the cost of two switches per container
(door+lid) plus the labor to install and wire them, etc. can add up
quickly.
Thanks to all for the suggestions received so far. Cyber brainstorming is a
great way to look at options we may not have otherwise considered.
Tim
tin that has a light sensor and music chip built into the lid. When I take
the lid off it plays music. This was a factory made unit. I have had it for
6 yrs now, and never saw dust being a problem on the photocell. They have
the cell recessed in the lid, inside a tiny hole. This protects the sensor
as well.
good luck
At 12:51 PM 4/11/02 -0400, you wrote:
>How about a simple reed switch on the edge of the container and a magnet
>attached to the top adjacent to it. When the top is closed, the magnet
>pulls the reed switch in. When the top opens, the reed switch opens too.
>
>Ray
>
>Mark Schmidt wrote:
>>
>> You might want to hack the MailBox arrival alarm from Radio Shack. The
>> sensor mounts in the mailbox. When opened, light hits it and transmits a
>> signal back to a receiver in the house. Caught the garbage man going
>> through the neighborhood mailboxes with it.
>>
>> Mark
>>
>>
Original Message
>> From: "Tim McDonough" <tim@m...>
>> To: <basicstamps@yahoogroups.com>
>> Sent: Thursday, April 11, 2002 10:43 AM
>> Subject: Re: [noparse][[/noparse]basicstamps] Tilt/Position Sensors
>>
>> > From: "Peter W Houlihan" <phouliha@m...>
>> > > If you look hard enough you can find the tilt sensors used in pin
>> > ball
>> > > machines. They work by having a small ball roll within a square
>> > enclosure
>> > > and depending on the orientation, close contact between a number of
>> > > contacts.
>> >
>> > Any idea who makes this type of switch? My concern would be cost.
>> >
>> > Another option is a photosensor. When the lid is on and the spring
>> > loaded door is closed it's dark inside the container. It will always
>> > be light outside the container any time someone is there to open it
>> > up.
>> >
>> > > I would stay away from mercury switches because eventually your
>> > switch
>> > > will end up in a land fill or incinerator and mercury is a nasty
>> > thing to
>> > > release into the environment. Car manufacturers are discontinueing
>> > use of
>> > > mercury switches to detect truck open/close for this very reason.
>> >
>> > Good point. It's so early in the project that I hadn't considered any
>> > "end of life" issues.
>> >
>> > Tim
>> >
>> >
>> >
>> > To UNSUBSCRIBE, just send mail to:
>> > basicstamps-unsubscribe@yahoogroups.com
>> > from the same email address that you subscribed. Text in the Subject and
>> Body of the message will be ignored.
>> >
>> >
>> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>> >
>> >
>>
>> To UNSUBSCRIBE, just send mail to:
>> basicstamps-unsubscribe@yahoogroups.com
>> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>>
>>
>> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
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>
>
>
sincerly
Kerry Barlow
[url=Http://mntnweb.com]Http://mntnweb.com[/url]
Binghamton online [url=Http://MntnWeb.Com/bing.htm]Http://MntnWeb.Com/bing.htm[/url]
> I'm working on an application where the sensor and electronics is
> mounted in the lid of a container. I want to sense when the lid of
the
> container is off or open so that the device can ignore readings
during
> this time period. Cost of the sensor/switch is an issue.
>
> My first thought was a mercury type switch like those found in wall
> thermostats. Any idea who makes these?
>
> Other options are a reed switch and magnet but the mechanics of
making
> sure it always aligns properly could be expensive.
>
> Another option is a photo sensor since the inside of the container
> would always be dark when the lid is closed. Possible problems could
> be dirt blocking the sensor.
>
> I'm open to other suggestions as well.
>
> Tim
Tim,
I recently purchased Tilt switches (PN: SW-4859) from International
Sensors and Controls (203) 270-9391. In my research, I have found
that problems can easily occur when using the ball operated tilt
switches. The steel ball will occasionaly stick and that may be a
problem for you. I elected to use the mercury switch and I have not
had any failure problems.
Steve
board) and check the readings. As you rotate it, the value (due to
gravity) will change...
http://products.analog.com/products/info.asp?product=ADXL202
Looks like about $10 in quantity...
Rory
--- In basicstamps@y..., "Tim McDonough" <tim@m...> wrote:
> I'm working on an application where the sensor and electronics is
> mounted in the lid of a container. I want to sense when the lid of
the
> container is off or open so that the device can ignore readings
during
> this time period. Cost of the sensor/switch is an issue.
>
> My first thought was a mercury type switch like those found in wall
> thermostats. Any idea who makes these?
>
> Other options are a reed switch and magnet but the mechanics of
making
> sure it always aligns properly could be expensive.
>
> Another option is a photo sensor since the inside of the container
> would always be dark when the lid is closed. Possible problems could
> be dirt blocking the sensor.
>
> I'm open to other suggestions as well.
>
> Tim
mechanical event state like an extreme case of over engineering.
Instead, I would recommend one of the slotted devices containing an IR
LED coupled with a phototransistor detector of the normally OFF type.
When the lid is opened, the detector signals an ON state, by detecting
the IR beam. About $2 in single quantity.
Dennis
Original Message
From: roscopsk [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=NU75BMUCSYMU6nOVvOS6tbD6xmgtJbtnDG2SO_g7-b_A-iI8Q_cuW_Oecp7f8-zfCDXCo8KChccQxvjFFg]rmackean@n...[/url
Sent: Thursday, April 11, 2002 2:04 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Tilt/Position Sensors
You could mount an accelerometer to the lid (right on your circuit
board) and check the readings. As you rotate it, the value (due to
gravity) will change...
http://products.analog.com/products/info.asp?product=ADXL202
Looks like about $10 in quantity...
like a clear plastic block with a ball bearing inside and several wires
sticking out of them. You can also make a ring of wire and suspend a
straight piece of spring wire with a weight on it through the middle of the
ring so that the weight makes the wire touch the ring if the object is
tilted.
Original Message
> If you look hard enough you can find the tilt sensors used in pin ball
> machines. They work by having a small ball roll within a square enclosure
> and depending on the orientation, close contact between a number of
> contacts.
>
> I would stay away from mercury switches because eventually your switch
> will end up in a land fill or incinerator and mercury is a nasty thing to
> release into the environment. Car manufacturers are discontinueing use of
> mercury switches to detect truck open/close for this very reason.
>
so the lever (Plunger) activates when the lid is opened. This is how the dome
light works on most automobiles.
Alan Bradford
Plasma Technologies