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    Vibration sensor

    I ran across a vibration sensor for $2 at http://www.goldmine-elec-products.co...?number=G15777

    A few years back I used a geophone sensor placed under a step on my staircase to detect when someone is going up the staircase. This provided a very positive indication of motion up the stairs that I could not achieve with a hawkeye because the hawkeye could not distinguish passing next to the stairs vs going up the stairs.

    There may be other creative ideas for using ultrasensitive vibration sensors.

    #2
    Michael,
    Could this be connected to a powerflash interface? It seems it could. Also is this a kit or a completed project?
    -Rupp
    sigpic

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      #3
      It looks to be a completed unit with a case. It outputs 5 VDC when activated so it will work with a powerflash, adi secu16, gameport or any other low voltage DC input. Attach a 5VDC relay and then it will work with the DS10A to get RF out of it. The relay from the same site is only another buck. I have bought things from them in the past and have been happy with my purchases.

      With my geophone interface I needed to build the interface and used the dusk/dawn hawkeye mod to make it an RF sensor. The DS10A is easier than the hawkeye and is supervised.

      What I did find with the high sensitivity of the geophone circuit is that it was sensitive to the quality of the power. I first used a cheap wallwart and needed to go to a filtered supply. I used the same supply for my water leak sensors that I have also placed under the house. I could have used batteries, but since there were under the house I did not want to deal with battery replacement maintenance.

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        #4
        Good find Michael!

        I'm thinking indicator for car running (mount near engine), placing on expensive items outdoors that you can't lock up, float on top of a swimming pool to let you know when someone jumps in, garage door traveling, washer/dryer/dishwasher running, etc...
        --------------------------------------------------
        **** Do You "Cocoon"? ****

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          #5
          Michael;

          Which 5VDC relay from that site is the "best" to use with this sensor for DS10A?

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            #6
            I'm just a tinkerer in the HW arena and not a theorist so be wary of any advise I give with HW. If I was going to buy a relay for this sensor without knowing anything else I would likely select the http://www.goldmine-elec-products.co...?number=G13763 because of its mid-value coil resistance and the clamping diode to protect it. Its DIP packaging is not ideal when not mounted in a circuit board so a little more care is needed for physical mounting. It is a SPST which means it is likely to be normally open and when vibration occurs it will close. This means the DS10A will report alert/on when no vibration and normal/off when vibration occurs. If you have a normally closed relay or a SPDT/DPDT type then you can wire it to invert the logic. In my case my xapmcsRF interface softare is able to invert the input so it does not matter if NC or NO contacts are used. The mcsMovement plugin will also do the inversion in software should you use that. Your event logic could also just invert the meaning of the ON/OFF just as well, but a little more confusing in the long term.

            The DS10A is expecting a reed swith dry contact that is activated by the magnet in normal installs. Any dry contact will work for that side of the relay. The 5VDC side of the relay is the one that will determine its userfullness in the application. You want a coil winding that that does not put too big a load on the circuit that is driving it. My guess is that any standard 5VDC coil relay will work with this vibration sensor. When the coil impedence becomes too high then false triggers are possible if the output circuit is not very clean. When too low then excessive current will be drawn and either be too much for the circuit to supply or quickly drain batteries if that is the power source.

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              #7
              Too good to pass up...

              Great find! Looks like a site is worth checking out from time to time to see what they have...

              I just ordered 4. Not sure what I'm going to do with them all yet, but the wife was grumbling this weekend about not knowing when the washer and dryer had stopped running.

              Also, was thinking about putting one on the sump pump to log when it turns on and off.

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                #8
                When you use the vibration sensor for pump or laundery you will likely want a direct connection rather an an RF/X10 one since it will be vibrating for a long time. I dont know if the circuit will generate repeated ON or a single ON when there is continuous vibration. When you get it you can experiment

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                  #9
                  I was thinking about that too...

                  ... but for 2 bucks each, even if I can never figure it out and scrap the whole thing, I'm only out 10 bucks!

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                    #10
                    I totally agree. I get stuff like this all the time just to see if I can make it work.

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                      #11
                      Thanks for the info Michael.

                      I too was thinking of using these for washer/dryer so good point about avoiding DS10 due to time it will be "on"; I guess I can use a powerflash unit instead.

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                        #12
                        The powerflash has the same problem. If the output of the circuit is not constant then you wil be getting many X10 transmissions and this will flood the powerline so nothing else X10 will work.

                        I notice in the add they indicate you can latch the output with a DPDT relay. I dont know what unlatches it, but this may be the solution to the problem if there is a problem. Give them a call since they did indicate they would provide the circuit with the DPDT relay.

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                          #13
                          Originally posted by Michael McSharry
                          .... I used the same supply for my water leak sensors that I have also placed under the house.
                          Michael - can you please describe these?

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                            #14
                            I have two type of water sensors at four locations and all are interfaced to supervised inputs of the ocelot secu16. Two are Rainbow Kits Water Alarm (www.rainbowkits.com) and two are overflow alarms that I picked up surplus for $1. I looked for my interface circuit for the overflow alarm and could not find it. I tapped into the buzzer and stretched the pulse so it would be present for a long time. While it is not the same circuit I used for the radar sentry interface that I attached, it is based on the same principle of using a 555 timer for signal conditioning. The radar sentry does interface to a DS10A. This circuit is in essence a radar to x10 rf interface. In this case I used a H11F1 rather than a relay so I would have 100% solid state interface. Rocco pointed me to the H11F1 device.

                            The probes for the overflow alarm look like two pins that are about 1/4 inch appart. It is much like the power plug one finds on the radio shack universal power adapters. The probes on the Water Alarm are two ear-like pieces of metal which would be appropriate for a flat surface mounting. Mine all all installed in depressions in the irregular surface under the house so detection of a minute water level was not too much of a concern.

                            I dont recall the power supply I used, but easily could have been a radio shack one that is 12VDC and filtered. It is a wallwart type.
                            Attached Files

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                              #15
                              As a curiosity I tried the vibration sensor from Goldmine. It has 9VDC input and a DC output. I tied the output to the Magnecraft W107DIP-5 relay they sold for $1 and a DS10A to the output of the relay. It works pretty much as expected with each tap of the sensor generating an ON followed by OFF.

                              What I did not expect is that the sensor only generated the pulse on a change of vibration. I suspect if it is mounted on a washing machine or dryer the DS10A will only send the ON/OFF pair when they start and when they stop. It looks live the vibration state must remain steady for about a second before a change of vibration is delivered. If this 1-second value is not quite correct for the intended application then signal conditioning could be done with something like mcsMovement or xapmcsRF to get something more usable for control. When the washer cycles between modes such as fill and wash the pause may be sufficient to generate an ON/OFF pair and look like the machine is finished when it is only changing modes.

                              It is not as sensitive as a geophone. On a hardwood floor it would trigger when walking within about 3 ft of it with bare feet. It would not trigger when walking on padded carpet such as the geophone was able to do.

                              The unit comes with a nice plastic case with mounting tabs and holes so the install should not be too bad. It has a 5 pin male connector with pin spacing of 0.1". I did not have the female end of this in my junk box so I cut up an IDE flat cable and used the bench grinder to pare it down to a the desired size. I first tried it with an old 9VDC battery that was only putting out about 6VDC. It did not work at this level, but it could be that by the time the battery was loaded under the circuit the voltage was much less than 6 VDC. I did not try it with an external power supply so I do not know what its sensitivity is to the quality of the power source.

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