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Cow feeder!!

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by gibby106141, Oct 24, 2011.

  1. gibby106141

    gibby106141 New Member

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    I am wanting to build a circuit which controls a solenoid on/off to feed some cows.

    I was wondering if anyone here could offer me some solutions? (12vdc)

    The circuit should power a relay on/off, the pulse duration should be adjustable between 1-10 seconds.

    The output pulses should be adjustable by a binary? switch located on the unit to control the number of pulses out of the circuit - i.e. a 16 position switch, when set at 1, one pulse on/off is generated, or when set on 16, sixteen pulses on/off are generated.

    The unit once completed its output count should reset ready for the next cow.

    The circuit should be controlled by a momentary push button.

    Any help anyone could offer would be greatly appreaciated - I was orignally thinking of using a 555 timer to give me my output pulse, but then couldnt work out how to control it to preset values.

    Regards
     
  2. alec_t

    alec_t Well-Known Member Most Helpful Member

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    You can use a 555 to generate a pulse of 1-10 secs duration, but for generating a sequence of such pulses you will need additional ICs, including a counter. What is the interval between pulses?
     
  3. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi gibby,
    This is one option, I would need to know more details of your relay and BIN switch in order to complete the circuit.
     

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  4. dave

    Dave New Member

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  5. gibby106141

    gibby106141 New Member

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    Thank you both for your replies - I am new to circuits - but have been in the electricity business for 15+ years, and wanted to try and undertand a few more things but got totally stuck on how to do this!

    I'd worked out how to get my pulse from a 555 but then couldnt undertsand how to A) start it with a pulsed input and B) limit the number of output pulses.

    I was thinking of a binary switch with 16 positions - one being zero, the other being the number of pulsed on operations, similar to the type shown herehttp://elma.com/Americas/English/Products/RotarySwitches_4/CodedSwitches_47.aspx

    The relay would be a 12dv coil, with a contact rating of 240v No greater than 3 Amps
     
  6. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    him
    Looking at that switch link it shows a 16 position Grey encoded type, I would advise against using that type for this circuit.

    A 16 position, rotary switch, contacts as 4 Bit Binary.
    http://uk.farnell.com/jsp/search/br...ions=false&ref=globalsearch&_requestid=182618

    Ref the relay, say the feed was set for 2, 10 sec periods, do you want the relay to de-energise between each 10 sec period, is yes, how long for.??

    EDIT:
    Datasheet
     

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    Last edited: Oct 24, 2011
  7. gibby106141

    gibby106141 New Member

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    Thanks for all your help -

    I want it to (once the button has been pressed) energise for 6 seconds (relay on) then de-energise for 6 seconds, then depending on how many ON pulses I want continue until the preset figure is reached then just go to the OFF state again.
     
  8. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi,
    This will give an equal On/Off period for the Relay.

    Use a N/O push switch connected as shown on the left of the drawing to start the cycle
     

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  9. gibby106141

    gibby106141 New Member

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    Eric,

    Thank you so much for your help, a few further questions what are c6 and c7 doing are they tied down to ground/0v, same as ud and Reset? Also are all the p1 connected together?

    Again thank you very much for your help

    Regards

    Mark
     
  10. alec_t

    alec_t Well-Known Member Most Helpful Member

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    @Eric
    I leave you to answer the OP's questions.
    Note: The DIS output of the 555 is shown unconnected (so the 555 only gives one pulse as it stands). Also, shouldn't the CIN input of the counter be grounded?
     
  11. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi,
    ALL the ground 'triangles' are connected to the 0V line.

    The p1 in RED is linked to all the other p1 RED's
     
  12. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi alec,
    That method of connecting with the top of the timing resistor connected back to to the output pin is common practice, it gives close to a 50:50 mark/space output.
    If required you can add a 10K from the DIS to +V and use it as a secondary output.

    I will look at CIN , never had a problem in practice.???
     
  13. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Oops, mea culpa. I had it connected to V+.:eek:
    I see in the sim you've got the .ic directive which has the effect of making the first pulse width the same as for following pulses. In reality, though the width of the first pulse is ~8.8 secs when the following pulses are 6 sec. Bonus for the cows!
     
  14. crutschow

    crutschow Well-Known Member Most Helpful Member

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    Eric, don't understand that you have a question about this. I'm sure you are aware the good practice is to tie all unused CMOS inputs to ground or V+. Otherwise erratic behavior is a distinct possibility.
     
  15. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    Carl,
    I dont have a question about it...;)

    I often use them without the pin connected, do you have any user experience with problems on this particular device that you could quote.??
    The d/s shows the input pins on this IC do have additional diodes etc, that do provide some degree of pull up thru diode leakage.

    EDIT:
    Perhaps you could post your version of a suitable circuit for the OP.???
     
    Last edited: Oct 24, 2011
  16. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi alec,
    After consideration I think it would be prudent to connect CIN to 0V, lets have belt and braces for the Cows.!!:rolleyes:

    hi Mark,
    Connect CIN pin on the CD4516 to 0V , another ground triangle,!
     
    Last edited: Oct 25, 2011
  17. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi Mark,
    If you need help with the IC pin numbers, just ask.

    Checked the actual circuit on a BB, it works fine.

    Whats you location.?
     
  18. gibby106141

    gibby106141 New Member

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    Help again if possible?

    Ive made it in yenka?

    Can you see if I've made an obvious mistake - as I cant get it to work

    Thank you again for the help so far!
     

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  19. gibby106141

    gibby106141 New Member

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    Ive managed to get it to count up to 15 and then stop, but cant get it to stop at any of the other preset values, between 0 & 15
     
  20. crutschow

    crutschow Well-Known Member Most Helpful Member

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    You had question marks so I thought you had some question about that. Guess you were referring to whether anyone had a problem with leaving CIN unconnected.:confused:

    Certainly a particular CMOS device may allow operation without all the inputs tied, at least for a while, but subtle changes in the circuit, such as from moisture or noise pickup, could lead to erratic (and hard to trace) problems at a latter date. There are reverse-biased input protection diodes to both Vss and Vdd on standard CMOS circuits but I wouldn't depend upon those to provide a definite logic level as the leakage goes in both directions.
     
  21. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    Hi
    Depending upon which BIN switch type you decide to use, you will require resistor pull ups or downs on the parallel inputs to the 4516... Let me know.?

    I will look at your simulation in detail, BUT at first look you have the 4516 LD and CE wired wrong.!

    The circuit is working on my bench on a BB OK.
     

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