Circuit question

Discussion in 'General Electronics Chat' started by RobiaBill, Mar 7, 2007.

  1. RobiaBill

    Thread Starter New Member

    Mar 7, 2007
    4
    0
    I am wanting to build an automatic feeder for some of my farm animals. What I have in mind is using a car seat electric motor which haas a forward and a reverse. Next I would like to use a digital timer like used on deer feeders to operate the car seat motor. At a specific time the motor would turn 'out' to present the feeder bowl to the animal and at a specific time the motor would turn on to 'pull' the feeder bowl back under a barrell to be refilled. The problem is the digitial deer feeder timer only has one wire to the motor. Is it possible to use the deer feeder digital timer and if so how could I use it. Or are there 12 v timers that have multiple timers where one could be hooked up to the motor to make it go forward and one to make the motor go backwards. Sorry for the non-technical terms !! Thanx.
     
  2. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    That "one wire" would have some sort of current limit which is unknown. So you use that 'one wire' as a control and use it to control a relay. Then you can use as much voltage/current as the relay and your other power supply can take to do what ever you want.

    To do it with only one voltage would take something similar to a grain screw but smaller or some other device that can be turned on and off to fill a feeding container.

    This has no provisions for alarming on fail to feed, has no limit switches in case it feeds too much, etc. You'd probably want much more safety than fuse, you'd want several and to make sure the wiring is to code, relavant safety guidelines and environment proofed.
     
  3. awright

    Well-Known Member

    Jul 5, 2006
    84
    7
    Is there a particular reason you prefer the concept you described moving the bowl out and back under timer control? Aren't you going to have to create two distinct circuits and mechanisms, one to move the bowl and the second to fill the withdrawn bowl? Seems like extra work. I think mrmeval's concerns about safety are also important to consider. You don't want to capture an animal's snout while withdrawing the bowl.

    Wouldn't mrmeval's suggestion about using a feed screw be safer and easier to implement? Just turn on a feed screw that is totally contained within a tube for safety for a preset time and schedule. The tube would be positioned to drop the feed into the bowl.

    Use a time clock to feed at selected times of day and a TDR (Time Delay Relay) to control how long the feed screw turns after being initiated by the time clock.

    You could even get fancy and have a relay latch on, turning on an alarm light when the feeding occurs and a microswitch or optical circuit that unlatches the relay, turning off the light if feed passes a sensing paddle or a light beam.

    More details if interested.

    It is definitely possible to use a 1-wire motor, but either the motor or the power supply or both would have to be floating off ground introducing possible safety issues if the whole thing is line powered. Not insurmountable, though.

    awright
     
  4. RobiaBill

    Thread Starter New Member

    Mar 7, 2007
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    The concept for the 'bowl' moving back and forth is once the bowl is moved back, it is positioned under a barrel containing the feed which would free fall into the bowl filling it up. The out position of the bowl would present it to the animal. The auger concept is an interesting one also. But I would be interested in knowing more about the other. Any information you can provide is greatly appreciated. Thaxn.
     
  5. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Circuitry for he bowl will be more complicated than for the feed screw.

    Bowl: There will need to be sensors to stop the bowl at both ends of travel. There will need to be a means of reversing current through the motor, and of deciding whether the bowl needs to extend or retract.

    Screw: Turn on at designated hour and turn off after specified seconds/minutes elapse.
     
  6. RobiaBill

    Thread Starter New Member

    Mar 7, 2007
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    I am thinking the auger idea would work better. Can you tell me how to do it having to use a 12 volt system ? The barn is in a remote area without electricity. Thanx.
     
  7. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
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    Will you be using a battery, or will you be running conductors to the barn? The seat motor is 12v, being an automotive gizmo, but what about the feeder timer? Is it also a 12v gizmo?

    Your feeder timer should have a method for setting start and stop times on the auger. There should be some relay contacts on the feeder timer which can be used to power you seat motor. You'll need to experiment with how long to leave the auger running in order to give the cute critter a full meal.
     
  8. RobiaBill

    Thread Starter New Member

    Mar 7, 2007
    4
    0
    Yes the timer is 12 volt. Where can I purchase the motors and how do I determine what size I need ?
     
  9. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    I'm sorry for my misunderstanding - I thought you already had a motor salvaged from an automobile. I suggest checking local salvage yards.
     
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