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Detecting if 110VAC device is on or off with BS2

ArchiverArchiver Posts: 46,084
edited 2000-10-24 00:11 in General Discussion
I'm working on a stamp project that keeps track of when my sump-pump turns
on and off. I'm using a Dallas Semiconductor Real Time Clock to keep
track of time. The sump-pump runs on 110VAC and I'm not sure how to
detect if it is on or off. I'm thinking that I could set up a current
sensing device on one of the power lines going to the sump-pump. Any
ideas on how to do this?

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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 19:14
    have the pump trigger a relay (solid state)
    wich would give you an input on the stamp
    or have the pump power up the stamp that way it would only be on when the
    pump is on but you would have to be carefull with the rest of your circuit.
    regards.
    victor



    Original Message
    From: "Freddie Leaf" <freddie_leaf@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 1:19 PM
    Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > I'm working on a stamp project that keeps track of when my sump-pump turns
    > on and off. I'm using a Dallas Semiconductor Real Time Clock to keep
    > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > detect if it is on or off. I'm thinking that I could set up a current
    > sensing device on one of the power lines going to the sump-pump. Any
    > ideas on how to do this?
    >
    > __________________________________________________
    > Do You Yahoo!?
    > Yahoo! Messenger - Talk while you surf! It's FREE.
    > http://im.yahoo.com/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 19:22
    At 02:14 PM 10/22/00 -0400, you wrote:

    What's triggering the pump in the first place? ...chances are it could
    already be a relay.

    >have the pump trigger a relay (solid state)
    >wich would give you an input on the stamp
    >or have the pump power up the stamp that way it would only be on when the
    >pump is on but you would have to be carefull with the rest of your circuit.
    >regards.
    >victor
    >
    >
    >
    >
    Original Message
    >From: "Freddie Leaf" <freddie_leaf@y...>
    >To: <basicstamps@egroups.com>
    >Sent: Sunday, October 22, 2000 1:19 PM
    >Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    >
    >
    > > I'm working on a stamp project that keeps track of when my sump-pump turns
    > > on and off. I'm using a Dallas Semiconductor Real Time Clock to keep
    > > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > > detect if it is on or off. I'm thinking that I could set up a current
    > > sensing device on one of the power lines going to the sump-pump. Any
    > > ideas on how to do this?
    > >
    > > __________________________________________________
    > > Do You Yahoo!?
    > > Yahoo! Messenger - Talk while you surf! It's FREE.
    > > http://im.yahoo.com/
    > >
    > >
    > >

    Beau Schwabe IC Mask Designer
    National Semiconductor Network Products Division
    500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 19:38
    The pump is triggered by a float. The pump and float are submerged down
    in the sump-pump pit. The only thing I have access to is the 110VAC pump
    power cord going into the pit. I also have access to the pipe containing
    the water being pumped out of the pit. I guess I could get a flow meter
    but that sound expensive.



    --- Beau Schwabe <bschwabe@a...> wrote:
    > At 02:14 PM 10/22/00 -0400, you wrote:
    >
    > What's triggering the pump in the first place? ...chances are it could
    > already be a relay.
    >
    > >have the pump trigger a relay (solid state)
    > >wich would give you an input on the stamp
    > >or have the pump power up the stamp that way it would only be on when
    > the
    > >pump is on but you would have to be carefull with the rest of your
    > circuit.
    > >regards.
    > >victor
    > >
    > >
    > >
    > >
    Original Message
    > >From: "Freddie Leaf" <freddie_leaf@y...>
    > >To: <basicstamps@egroups.com>
    > >Sent: Sunday, October 22, 2000 1:19 PM
    > >Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    > >
    > >
    > > > I'm working on a stamp project that keeps track of when my sump-pump
    > turns
    > > > on and off. I'm using a Dallas Semiconductor Real Time Clock to
    > keep
    > > > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > > > detect if it is on or off. I'm thinking that I could set up a
    > current
    > > > sensing device on one of the power lines going to the sump-pump.
    > Any
    > > > ideas on how to do this?
    > > >
    > > > __________________________________________________
    > > > Do You Yahoo!?
    > > > Yahoo! Messenger - Talk while you surf! It's FREE.
    > > > http://im.yahoo.com/
    > > >
    > > >
    > > >
    >
    > Beau Schwabe IC Mask Designer
    > National Semiconductor Network Products Division
    > 500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
    >
    >
    >
    >
    >
    >
    >
    >
    >
    >


    __________________________________________________
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  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 19:54
    what about the switch at the float?
    Original Message
    From: "Freddie Leaf" <freddie_leaf@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 2:38 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.
    >
    >
    >
    > --- Beau Schwabe <bschwabe@a...> wrote:
    > > At 02:14 PM 10/22/00 -0400, you wrote:
    > >
    > > What's triggering the pump in the first place? ...chances are it could
    > > already be a relay.
    > >
    > > >have the pump trigger a relay (solid state)
    > > >wich would give you an input on the stamp
    > > >or have the pump power up the stamp that way it would only be on when
    > > the
    > > >pump is on but you would have to be carefull with the rest of your
    > > circuit.
    > > >regards.
    > > >victor
    > > >
    > > >
    > > >
    > > >
    Original Message
    > > >From: "Freddie Leaf" <freddie_leaf@y...>
    > > >To: <basicstamps@egroups.com>
    > > >Sent: Sunday, October 22, 2000 1:19 PM
    > > >Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    > > >
    > > >
    > > > > I'm working on a stamp project that keeps track of when my sump-pump
    > > turns
    > > > > on and off. I'm using a Dallas Semiconductor Real Time Clock to
    > > keep
    > > > > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > > > > detect if it is on or off. I'm thinking that I could set up a
    > > current
    > > > > sensing device on one of the power lines going to the sump-pump.
    > > Any
    > > > > ideas on how to do this?
    > > > >
    > > > > __________________________________________________
    > > > > Do You Yahoo!?
    > > > > Yahoo! Messenger - Talk while you surf! It's FREE.
    > > > > http://im.yahoo.com/
    > > > >
    > > > >
    > > > >
    > >
    > > Beau Schwabe IC Mask Designer
    > > National Semiconductor Network Products Division
    > > 500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    >
    >
    > __________________________________________________
    > Do You Yahoo!?
    > Yahoo! Messenger - Talk while you surf! It's FREE.
    > http://im.yahoo.com/
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 19:59
    At 11:38 AM 10/22/00 -0700, you wrote:
    The 110VAC is run through the float? Usually this is done with a lower
    12 or 24 Volt system that energizes a relay to handle the larger voltage
    and current demand of a motor.

    Anyway, a simple and safe solution would be to get a 110VAC Relay as
    mentioned earlier and place it in parallel with the 110VAC motor.


    >The pump is triggered by a float. The pump and float are submerged down
    >in the sump-pump pit. The only thing I have access to is the 110VAC pump
    >power cord going into the pit. I also have access to the pipe containing
    >the water being pumped out of the pit. I guess I could get a flow meter
    >but that sound expensive.
    >
    >
    >
    >--- Beau Schwabe <bschwabe@a...> wrote:
    > > At 02:14 PM 10/22/00 -0400, you wrote:
    > >
    > > What's triggering the pump in the first place? ...chances are it could
    > > already be a relay.
    > >
    > > >have the pump trigger a relay (solid state)
    > > >wich would give you an input on the stamp
    > > >or have the pump power up the stamp that way it would only be on when
    > > the
    > > >pump is on but you would have to be carefull with the rest of your
    > > circuit.
    > > >regards.
    > > >victor
    > > >
    > > >
    > > >
    > > >
    Original Message
    > > >From: "Freddie Leaf" <freddie_leaf@y...>
    > > >To: <basicstamps@egroups.com>
    > > >Sent: Sunday, October 22, 2000 1:19 PM
    > > >Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    > > >
    > > >
    > > > > I'm working on a stamp project that keeps track of when my sump-pump
    > > turns
    > > > > on and off. I'm using a Dallas Semiconductor Real Time Clock to
    > > keep
    > > > > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > > > > detect if it is on or off. I'm thinking that I could set up a
    > > current
    > > > > sensing device on one of the power lines going to the sump-pump.
    > > Any
    > > > > ideas on how to do this?
    > > > >
    > > > > __________________________________________________
    > > > > Do You Yahoo!?
    > > > > Yahoo! Messenger - Talk while you surf! It's FREE.
    > > > > http://im.yahoo.com/
    > > > >
    > > > >
    > > > >
    > >
    > > Beau Schwabe IC Mask Designer
    > > National Semiconductor Network Products Division
    > > 500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    >
    >
    >__________________________________________________
    >Do You Yahoo!?
    >Yahoo! Messenger - Talk while you surf! It's FREE.
    >http://im.yahoo.com/

    Beau Schwabe IC Mask Designer
    National Semiconductor Network Products Division
    500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 20:07
    You don't need to measure flow, just pressure. Mount the pressure sensor in
    the pipe so there is still a head above it. When the pump is off the water
    will drain out of the pipe and there is no pressure. When the pump kicks on
    you get the pressure of the head above the switch and the additional
    pressure that is requires to overcome the flow resistance in the rest of the
    pipe. There are plenty of pressure sensors for $20 or so that would do the
    job and if you looked at surplus you could probably find a on-off type
    sensor for $5 or so.

    Tim
    [noparse][[/noparse]Denver, CO]

    >
    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 21:33
    Freddie Leaf wrote:

    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.
    >

    not really.. talk to marine motor repair shops.. outboard motors are water
    cooled, and lots of them have flow switches that warn when the coolant water
    has stopped flowing.

    Jason


    >
    > --- Beau Schwabe <bschwabe@a...> wrote:
    > > At 02:14 PM 10/22/00 -0400, you wrote:
    > >
    > > What's triggering the pump in the first place? ...chances are it could
    > > already be a relay.
    > >
    > > >have the pump trigger a relay (solid state)
    > > >wich would give you an input on the stamp
    > > >or have the pump power up the stamp that way it would only be on when
    > > the
    > > >pump is on but you would have to be carefull with the rest of your
    > > circuit.
    > > >regards.
    > > >victor
    > > >
    > > >
    > > >
    > > >
    Original Message
    > > >From: "Freddie Leaf" <freddie_leaf@y...>
    > > >To: <basicstamps@egroups.com>
    > > >Sent: Sunday, October 22, 2000 1:19 PM
    > > >Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    > > >
    > > >
    > > > > I'm working on a stamp project that keeps track of when my sump-pump
    > > turns
    > > > > on and off. I'm using a Dallas Semiconductor Real Time Clock to
    > > keep
    > > > > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > > > > detect if it is on or off. I'm thinking that I could set up a
    > > current
    > > > > sensing device on one of the power lines going to the sump-pump.
    > > Any
    > > > > ideas on how to do this?
    > > > >
    > > > > __________________________________________________
    > > > > Do You Yahoo!?
    > > > > Yahoo! Messenger - Talk while you surf! It's FREE.
    > > > > http://im.yahoo.com/
    > > > >
    > > > >
    > > > >
    > >
    > > Beau Schwabe IC Mask Designer
    > > National Semiconductor Network Products Division
    > > 500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    > >
    >
    > __________________________________________________
    > Do You Yahoo!?
    > Yahoo! Messenger - Talk while you surf! It's FREE.
    > http://im.yahoo.com/
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 21:49
    I gave answer about a similar question (detecting pulse as AC Input) to this
    group recently.
    The circuit is also OK for your goal too.

    Attached the file AC_interface.jpg, this schematic is from an european
    magazine called "Elektor". Sorry the background of the schematic is not
    cleaned it up.

    It works fine, and tested again a few days ago with scope:
    - 110 AC is applied to a LED of opto across 100k resistor (about 1mA through
    the Led), don't forget diode 1N4148 or similar.
    - 4N25 opto is little bit better than TIL111.
    - Wire 10k as R3 instead of 5k6.
    - T1 is general purpose NPN (BC547, 2N2222,...).
    - BStamp input in collector of T1.

    1/ Without C1 you have a perfect square wave 60Hz (Low state 0v, High state
    5v).

    2/ With C1 100nF you can detect if AC is applied or not!
    Signal is: Low state 0v during 8.3 ms, going from 0 to approximately 0.4v
    during 8.3ms. Total cycle 16.6ms for 60Hz.
    When AC isn't applied, input on BS2 is 1.
    When AC is applied, input on BS2 is 0.

    Sorry, I haven't tested any BS2 code about this recently for the 1/ case.

    Notice to AC supply: opto is necessary to have insulation with projects.
    On schematic given, 2 serial resistors are in use for 230V (resistor is rated
    150V). For US 1 resistor 100k is OK, wire 2 of these if you like.

    Let me know if you need more, or problem to get attached JPG file.

    Have fun in your projects

    Christian.

    [noparse][[/noparse]Unable to display image]
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 22:00

    Original Message
    From: Freddie Leaf <freddie_leaf@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 2:38 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.

    *****************
    It does not sound practical to tap into the pump wiring...it is usually all
    sealed on a submersible pump. Consider a current sense transformer that
    could be installed on an extension line cord. Digikey lists a unit on page
    593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
    (220 mv/amp with 120 ohm). The output could be rectified and conditioned
    for Stamp use.

    Ray McArthur
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 23:16
    Hi Ray:

    Yours and Christian's ideas were really neato.

    Ray, can I ask what a terminating resistor is?
    You lost me on the "which would double for a 120 ohm" too.

    Just stick a 60 ohm or 120 ohm on the outputs of the current sense
    transformer and you get some kinda output that you can work with thru a
    diode bridge or something?

    Anyway, sure enjoy this board.

    Mark

    Original Message
    From: Ray McArthur <rjmca@u...>
    To: basicstamps@egroups.com <basicstamps@egroups.com>
    Date: Sunday, October 22, 2000 1:52 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    >
    Original Message
    >From: Freddie Leaf <freddie_leaf@y...>
    >To: <basicstamps@egroups.com>
    >Sent: Sunday, October 22, 2000 2:38 PM
    >Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    >
    >
    >> The pump is triggered by a float. The pump and float are submerged down
    >> in the sump-pump pit. The only thing I have access to is the 110VAC pump
    >> power cord going into the pit. I also have access to the pipe containing
    >> the water being pumped out of the pit. I guess I could get a flow meter
    >> but that sound expensive.
    >
    >*****************
    >It does not sound practical to tap into the pump wiring...it is usually all
    >sealed on a submersible pump. Consider a current sense transformer that
    >could be installed on an extension line cord. Digikey lists a unit on page
    >593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    >resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
    >(220 mv/amp with 120 ohm). The output could be rectified and conditioned
    >for Stamp use.
    >
    >Ray McArthur
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-22 23:56
    Well he is a change. Something I can add a thought on. You could wind a coil
    yourself and place around one of the conductors only, Either the active or
    neutral (I am a sparky here in Oz and that's what we call them anyway).
    Depending on the number of turns and if a former is used etc will cause a
    voltage to appear at the coil ends. It's rough but if it serves to work then
    perhaps a commercial version could be bought.

    Hope this helps....

    Original Message
    From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=lgHYzg2MUq--Mx70riAa6LrCMENvEKwRfdFtxaM3fZrhiEvctbdtN7obwF39L9fmnHUdDUjfGwXrMTn5F5js]rjmca@u...[/url
    Sent: Monday, 23 October 2000 7:00
    To: basicstamps@egroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    BS2


    Original Message
    From: Freddie Leaf <freddie_leaf@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 2:38 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.

    *****************
    It does not sound practical to tap into the pump wiring...it is usually all
    sealed on a submersible pump. Consider a current sense transformer that
    could be installed on an extension line cord. Digikey lists a unit on page
    593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
    (220 mv/amp with 120 ohm). The output could be rectified and conditioned
    for Stamp use.

    Ray McArthur
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 00:55
    Thank you everyone for all the great ideas. Great List!!

    Ray, how do you suggest hooking up the Digikey current sensing device. I
    would think you need break into either the hot or common circuit going to
    the pump motor and insert the current sensor in series (pins 1A and 2A)
    with one of these circuits? Thanks.


    --- Ray McArthur <rjmca@u...> wrote:
    >
    Original Message
    > From: Freddie Leaf <freddie_leaf@y...>
    > To: <basicstamps@egroups.com>
    > Sent: Sunday, October 22, 2000 2:38 PM
    > Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    > BS2
    >
    >
    > > The pump is triggered by a float. The pump and float are submerged
    > down
    > > in the sump-pump pit. The only thing I have access to is the 110VAC
    > pump
    > > power cord going into the pit. I also have access to the pipe
    > containing
    > > the water being pumped out of the pit. I guess I could get a flow
    > meter
    > > but that sound expensive.
    >
    > *****************
    > It does not sound practical to tap into the pump wiring...it is usually
    > all
    > sealed on a submersible pump. Consider a current sense transformer that
    > could be installed on an extension line cord. Digikey lists a unit on
    > page
    > 593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    > resistor, it outputs 110 mv/amp, whch would double for a 120 ohm
    > resistor,
    > (220 mv/amp with 120 ohm). The output could be rectified and
    > conditioned
    > for Stamp use.
    >
    > Ray McArthur
    >
    >
    >
    >


    __________________________________________________
    Do You Yahoo!?
    Yahoo! Messenger - Talk while you surf! It's FREE.
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  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 01:08
    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.

    Maybe an audio piezo-film pickup or a strain gage mounted on the water pipe
    could pick up vibrations from the pump, to be amplified and decoded by the
    stamp.

    -- Tracy
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 01:54
    here is a question ?
    if at the discharge hose of the pump.
    you push in 2 stainless needles side by side about 1/2'' apart and you
    attach wires to the pins when the pump turns on and the water runs would
    this be a switch????
    and would it be enough to trigger an input on the stamp???
    just a thought ..
    victor
    Original Message
    From: "Peter May" <manager@s...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 6:56 PM
    Subject: RE: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > Well he is a change. Something I can add a thought on. You could wind a
    coil
    > yourself and place around one of the conductors only, Either the active or
    > neutral (I am a sparky here in Oz and that's what we call them anyway).
    > Depending on the number of turns and if a former is used etc will cause a
    > voltage to appear at the coil ends. It's rough but if it serves to work
    then
    > perhaps a commercial version could be bought.
    >
    > Hope this helps....
    >
    >
    Original Message
    > From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=GTtTmd1qylEo1yhLTVIfbVOg8RQsYNfAyzkUHTA2u6VJsuN8z54e_Z7A3bis-SFonIiOgsq-O3IFpw]rjmca@u...[/url
    > Sent: Monday, 23 October 2000 7:00
    > To: basicstamps@egroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    > BS2
    >
    >
    >
    Original Message
    > From: Freddie Leaf <freddie_leaf@y...>
    > To: <basicstamps@egroups.com>
    > Sent: Sunday, October 22, 2000 2:38 PM
    > Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    BS2
    >
    >
    > > The pump is triggered by a float. The pump and float are submerged down
    > > in the sump-pump pit. The only thing I have access to is the 110VAC
    pump
    > > power cord going into the pit. I also have access to the pipe
    containing
    > > the water being pumped out of the pit. I guess I could get a flow meter
    > > but that sound expensive.
    >
    > *****************
    > It does not sound practical to tap into the pump wiring...it is usually
    all
    > sealed on a submersible pump. Consider a current sense transformer that
    > could be installed on an extension line cord. Digikey lists a unit on
    page
    > 593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    > resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
    > (220 mv/amp with 120 ohm). The output could be rectified and conditioned
    > for Stamp use.
    >
    > Ray McArthur
    >
    >
    >
    >
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 03:17
    the trigger is either a float and switch, or an internal pressure switch.
    this is the only method ive ever seen.

    norm



    >From: Beau Schwabe <bschwabe@a...>
    >Reply-To: basicstamps@egroups.com
    >To: basicstamps@egroups.com
    >Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    >Date: Sun, 22 Oct 2000 14:22:07 -0400
    >
    >At 02:14 PM 10/22/00 -0400, you wrote:
    >
    >What's triggering the pump in the first place? ...chances are it could
    >already be a relay.
    >
    > >have the pump trigger a relay (solid state)
    > >wich would give you an input on the stamp
    > >or have the pump power up the stamp that way it would only be on when the
    > >pump is on but you would have to be carefull with the rest of your
    >circuit.
    > >regards.
    > >victor
    > >
    > >
    > >
    > >
    Original Message
    > >From: "Freddie Leaf" <freddie_leaf@y...>
    > >To: <basicstamps@egroups.com>
    > >Sent: Sunday, October 22, 2000 1:19 PM
    > >Subject: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
    > >
    > >
    > > > I'm working on a stamp project that keeps track of when my sump-pump
    >turns
    > > > on and off. I'm using a Dallas Semiconductor Real Time Clock to keep
    > > > track of time. The sump-pump runs on 110VAC and I'm not sure how to
    > > > detect if it is on or off. I'm thinking that I could set up a current
    > > > sensing device on one of the power lines going to the sump-pump. Any
    > > > ideas on how to do this?
    > > >
    > > > __________________________________________________
    > > > Do You Yahoo!?
    > > > Yahoo! Messenger - Talk while you surf! It's FREE.
    > > > http://im.yahoo.com/
    > > >
    > > >
    > > >
    >
    >Beau Schwabe IC Mask Designer
    >National Semiconductor Network Products Division
    >500 Pinnacle Court, Suite 525 Mail Stop GA1 Norcross, GA 30071
    >
    >
    >
    >
    >
    >
    >
    >
    >
    >

    _________________________________________________________________________
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  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 03:57

    Original Message
    From: Freddie Leaf <freddie_leaf@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 7:55 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > Ray, how do you suggest hooking up the Digikey current sensing device. I
    > would think you need break into either the hot or common circuit going to
    > the pump motor and insert the current sensor in series (pins 1A and 2A)
    > with one of these circuits? Thanks.

    Yes, you could do it on a short extension cord so as to not mess with the
    pump cord, and insert the primary (1A and 2A) in series with one of the
    legs. It is probably best to place it in the hot side to maintain
    common-side integrity. The output winding is pins 5 and 8 where you connect
    the resistor and detection circuitry.

    You could connect a full wave bridge to the secondary, with the load
    resistor on the bridge output to derive DC voltage for your detection
    circuitry.

    A current transformer is just a two-winding transformer with a small number
    of turns on the sense, (input), winding and many turns on the output
    winding. Being a "step-up" transformer, it steps up the primary voltage,
    and steps down the primary current. It is normally loaded like "shorted"
    transformer so as to minimally disturb the circuit it is in series with.
    The Digikey unit is a 1/500 transformer. So if your pump draws 10 amps, 10
    amps flows in the primary, and 10/500 or 20 ma flows in the secondary. With
    a 60 ohm resistor across the secondary, the secondary voltage is 20 ma * 60
    ohms=1.2 volts. The catalog spec is 110 mv/amp, or 1.1 volts for 10 amps
    which is less than the ideal 1.2 volts because of transformer losses. You
    can increase the load resistor for more output voltage, but losses increase
    as you do this, and output falls more below the ideal.

    Ray McArthur
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 04:05
    Victor:

    The resistance between the needles would decrease with water flow, but would
    be very unpredictable, depending on what contaminants are in the water at
    the time. It also depends on sense voltage and current.

    Ray McArthur

    > here is a question ?
    > if at the discharge hose of the pump.
    > you push in 2 stainless needles side by side about 1/2'' apart and you
    > attach wires to the pins when the pump turns on and the water runs would
    > this be a switch????
    > and would it be enough to trigger an input on the stamp???
    > just a thought ..
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 04:11
    Put a micro switch on the pump float mechanism.

    Ben

    Tracy Allen wrote:

    > > The pump is triggered by a float. The pump and float are submerged down
    > > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > > power cord going into the pit. I also have access to the pipe containing
    > > the water being pumped out of the pit. I guess I could get a flow meter
    > > but that sound expensive.
    >
    > Maybe an audio piezo-film pickup or a strain gage mounted on the water pipe
    > could pick up vibrations from the pump, to be amplified and decoded by the
    > stamp.
    >
    > -- Tracy
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-23 15:23
    I use current sensing as well with arrays of large resistive loads. It is by
    far the simplest and safest method.

    Original Message
    From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=3HGAkPAY_MQuS4sIOEzYENVFbqQFT55oCWwN8mIyscqTAN_YLH95cdobWYGW3y4YUTkQXUMuhiUk6g]rjmca@u...[/url
    Sent: Sunday, October 22, 2000 4:00 PM
    To: basicstamps@egroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    BS2


    Original Message
    From: Freddie Leaf <freddie_leaf@y...>
    To: <basicstamps@egroups.com>
    Sent: Sunday, October 22, 2000 2:38 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > The pump is triggered by a float. The pump and float are submerged down
    > in the sump-pump pit. The only thing I have access to is the 110VAC pump
    > power cord going into the pit. I also have access to the pipe containing
    > the water being pumped out of the pit. I guess I could get a flow meter
    > but that sound expensive.

    *****************
    It does not sound practical to tap into the pump wiring...it is usually all
    sealed on a submersible pump. Consider a current sense transformer that
    could be installed on an extension line cord. Digikey lists a unit on page
    593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
    (220 mv/amp with 120 ohm). The output could be rectified and conditioned
    for Stamp use.

    Ray McArthur
  • ArchiverArchiver Posts: 46,084
    edited 2000-10-24 00:11
    could something be done at the discharge hose ?
    perhaps a water container would fill and trigger a switch, put a small hole
    in container so water could
    drain once pump stopped!! or maybe a flapper at the end of the hose .
    victor faria
    Original Message
    From: "Chris Loiacono" <chris01@t...>
    To: <basicstamps@egroups.com>
    Sent: Monday, October 23, 2000 10:23 AM
    Subject: RE: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2


    > I use current sensing as well with arrays of large resistive loads. It is
    by
    > far the simplest and safest method.
    >
    >
    Original Message
    > From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rksv_TwaDl4XHOcrM0ENU_UX6Z-XV7PttBv4vELF9coLyUMWNJhrNegSJ1WXYL5ItHdSh-pL9pznWQ]rjmca@u...[/url
    > Sent: Sunday, October 22, 2000 4:00 PM
    > To: basicstamps@egroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    > BS2
    >
    >
    >
    Original Message
    > From: Freddie Leaf <freddie_leaf@y...>
    > To: <basicstamps@egroups.com>
    > Sent: Sunday, October 22, 2000 2:38 PM
    > Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
    BS2
    >
    >
    > > The pump is triggered by a float. The pump and float are submerged down
    > > in the sump-pump pit. The only thing I have access to is the 110VAC
    pump
    > > power cord going into the pit. I also have access to the pipe
    containing
    > > the water being pumped out of the pit. I guess I could get a flow meter
    > > but that sound expensive.
    >
    > *****************
    > It does not sound practical to tap into the pump wiring...it is usually
    all
    > sealed on a submersible pump. Consider a current sense transformer that
    > could be installed on an extension line cord. Digikey lists a unit on
    page
    > 593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
    > resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
    > (220 mv/amp with 120 ohm). The output could be rectified and conditioned
    > for Stamp use.
    >
    > Ray McArthur
    >
    >
    >
    >
    >
    >
    >
    >
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