Controlling Motors with Infrared Light

Discussion in 'The Projects Forum' started by balsaboom, Nov 12, 2013.

  1. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    Hi everyone,
    I'm looking to create a circuit where an infrared detector is located above the edge of a small wooden disk with an infrared light also on its edge. I want to wire this up so that while the detector does not see the light, power is supplied to a motor that will turn the small wooden disk (and thus eventually put the infrared light into the detectors angle of view). However, I also want to wire it so that when the detector actually does see light, another, separate motor is activated.

    Is this any way to do this without the use of IC's?

    thanks for reading!
     
  2. #12

    Expert

    Nov 30, 2010
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    If you are going to do this with light, electronics will be involved. Have you thought about a microswitch? A simple lever operated switch with 3 pins, one for power, 2 that take turns being connected to the power.

    There is also a way to do it with magnetism, but that would also need some electronics.
     
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  3. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    No, I haven't thought about using a microswitch.
    What would i be connecting to NO and NC?
     
  4. #12

    Expert

    Nov 30, 2010
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    The motors.

    If they are too big for the 10 amp switch, use relays.
     
  5. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    From what I see, the microswitches usually have a lever with a (toggle, im assuming) button below them. Is this toggle required for operation, or can it be handsfree?
     
  6. #12

    Expert

    Nov 30, 2010
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    You have to move the little button for the switch to work. Some come with levers, some come with rollers, some just have the little bump.
     
  7. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    Is this any way I could get the switch to work automatically? or would that require an IC.
     
  8. killivolt

    Active Member

    Jan 10, 2010
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    I think the problem is we don't get what it is that is needed?

    #12 has one of the best suggestions I can think of, very simple approach. Many motors for a very long time before electronics were control by such switches.

    He maybe able to help you with more information.

    What is it you want to do?
     
  9. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    Basically, I will have a round turntable with an IR light on the edge. There will also be an IR receiver hanging directly above the edge. I want to move a motor when the IR receiver sees the IR light, and when the IR receiver doesn't see an IR light, it will turn the table (because that will cause the IR light to eventually come to it). If i block out the IR light though, the table should resume turning and the other motor should stop, until the IR light and IR receiver are in accord once again.

    I hope that made sense, If you want more clarification I'd be happy to provide some. Thanks so much!
     
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  10. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Add a latching relay to keep second motor running after bump has passed. What stops the motors?
     
  11. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    Ideally, I would like some type of way to be able to stop it after 3 stop/go rounds (e.g. starts off not seeing the light, table turns, sees the light, other motor activates, the light is blocked, table turns, sees the light, other motor activates, the light is blocked, table turns, sees the light, other motor activates, the light is blocked) but I'm pretty sure that isn't feasible. The application I'm using it for, however, doesnt require that the motors be eventually turned off so it isnt at the forefront of my problems at the moment.
     
  12. killivolt

    Active Member

    Jan 10, 2010
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    There is 2 motors and with cam followers it is possible, but what starts the hole event?
     
  13. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    I think maybe it'd be better to give a holistic overview of the application.
    I'm trying to create a machine that, when a mixture of marbles, golf tees, and paperclips are poured into it, is able to sort out the 3 materials into 3 containers autonomously.
    The way I'm attempting to do it is like this:
    I will pour the mixture down a metal chute (there is an active electromagnet on the chute that causes the paperclips to stick), then the tees and marbles proceed into a funnel. There is a piece of wood that is covering the opening of the funnel, so that the tees essentially accumulate at the bottom of the funnel. The wood piece doesn't directly cover the funnel, however, it is a few centimeters below the funnel's exit. As a result, the tee's are stuck there (because they are too tall to fit through), while the marbles roll right through.

    There will be a round wooden disk connected to a motor (so that the disk basically acts as a revolving table) with 3 clear containers on it. Underneath each of the clear containers is an infrared light. I will place the IR receiver on the funnel, so that it can essentially differentiate when there is an empty container below the mouth of the funnel.

    The container starts at the bottom, and when the marbles roll in, the infrared light is blocked. As a result, the motor kicks in and the table rotates, until it sees the next infrared light (and thus the next container, as the IR light is under the container). It then activates another motor that will swivel the wood piece blocking the funnel away, allowing the tees to fall in. The tees will occlude the IR light, and once again the table will turn until it reaches the final container and final IR light. When this happens, I want to be able to turn off the electromagnet and activate a small vibrating motor on the metal chute (to ensure that all the paperclips get off the chute, and aren't held there by residual magnetic forces). Then, the paperclips will fall into the container.

    If that needs more explaining, please let me know. Thanks for helping me, I'm really learning alot about the different ways I could take this. If you have another idea for sorting these objects, feel free to let me know as well
     
  14. MaxHeadRoom

    Expert

    Jul 18, 2013
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    You also need to explain how accurate you need the positioning, if any?
    This can dictate the motor technology and control.
    Simple DC motors can overrun a position unless steps are taken, such as add friction or or other simple means.
    Max.
     
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  15. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    The accuracy isnt all that important, as the containers themselves are quite large. Just as long as its in the relative neighborhood, it would definitely be fine.

    edit: just out of curiosity, how would you increase the accuracy?
     
  16. MaxHeadRoom

    Expert

    Jul 18, 2013
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    You may be able to use RC servo's?
    Also for non servo control a simple friction damper can be applied to the motor shaft or rotor etc, to prevent overrun.
    And depending on the speed and inertia of the table you may require deceleration, which then means a known point to start the decel.
    These are all factors that have to be taken into consideration, if needed.
    Max.
     
  17. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    It has to be completely autonomous after I pour the mixture into the machine, so I think RC is out of the question.
    I'm going to be spinning the wood very slowly, so I doubt inertia will be a problem, I'll definitely use a friction damper though.
     
  18. MaxHeadRoom

    Expert

    Jul 18, 2013
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    There are a few other things that need to be considered before you decide on the method of control.
    Does the system operate in a continuous mode or initiated by start/stop P.B?
    Can the process be completed without timers, end of move, bin full etc?
    As someone has already mentioned, this was done in earlier times with relay logic, but mechanical timers can get expensive.
    Is this to be a very low budget project? as one solution which is relatively easy to implement is to use a Smart Relay, this is a miniature PLC with timers etc all included, there are half a dozen manufacturer's of these, basically all identical as they are mostly relabeled.
    They can also be obtained off ebay, and most supply the PC software for them, although they can also be programmed by the front buttons.
    Max.
     
  19. balsaboom

    Thread Starter New Member

    Nov 12, 2013
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    What is a P.B.?
    For the application that I'm using, it doesn't matter if its continuous / eventually stops. I'm going to have the IR light under the detector (and thus a container under the funnel) to begin, so it doesn't have to be initiated in any way.

    Its not necessarily a low budget project, but I'd obviously like to minimize money spent ;). Would a series of relays serve to fulfill my objective / how would I implement it.

    I would use the smart relay, but I cannot use anything in the machine except for wires, batteries, photovoltaic cells, photodiodes, photoresistors, phototransistors, light bulbs, LEDs, homemade solenoids, and switches.
     
  20. MaxHeadRoom

    Expert

    Jul 18, 2013
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    P.B. = Push Button.
    So this is some kind of test project?
    It is going to be a bit restrictive if no other electronic devices are allowed and that is the extent of the shopping list!
    Max.
     
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