Linear Actuator and Proximity Sensor Circuit

Discussion in 'The Projects Forum' started by Curly Fries, Oct 1, 2015.

  1. Curly Fries

    Thread Starter New Member

    Oct 1, 2015
    Hello, I am a complete novice and need some advice on what components to get for a small circuit with a linear actuator and proximity sensor. I want it so whenever the proximity sensor isn't detecting anything the linear actuator goes and stays up, and when the proximity sensor is detecting something the linear actuator goes and stays down. I need the proximity sensor to have a range of about 1-2 meters and the circuit to be a small as possible. I also have a relatively small budget so I do not want to be paying more than around £20-50 for all of the components. What components would I need to get and how would I make this basic circuit?
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    You can buy a linear actuator (12Vdc motor powered) with a built-in precision linear pot. I used such to make an automatic car gate actuator. I used an Arduino as a controller. The pot tells the controller where the gate is, when to start slowing, which direction to go on the next button push, etc.

    Unfortunately, the linear actuator I bought for this project does not meet your cost objective. However, I have been able to scrounge some similar actuators (that were too slow for the gate) without feedback pots. If you are handy, you could add a feedback pot to the gear train of the actuator...
    Curly Fries likes this.
  3. AnalogKid

    AAC Fanatic!

    Aug 1, 2013
    What is the linear actuator actuating? Size, weight, function, connectivity, etc?
    What is the proximity sensor sensing? Metal, people, optical, magnetic, infrared, etc?
    Is the completed project going to be indoors or outside in the weather?

  4. Curly Fries

    Thread Starter New Member

    Oct 1, 2015
    It will be actuating a small metal rod that is about 14cm long, 20 to 30 grams and will be at a right angle to the actuator. I would like the sensor to sense any walls, people, tables etc in the surrounding environment. The completed project will be for use indoors.
  5. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    What you are asking for is a complete design, a list of components won't be any use on its own and this assumes that you have the skills to assemble the electronics. What electronics have you built before?

    You still haven't provided enough information; we know nothing power-supply requirements of the linear actuator (perhaps you could choose one that you think is suitable) nor do we know the area of coverage of the proximity sensor; 1-2m doesn't really help. Draw a diagram or state the application or leave everyone guessing... and when you say it shouldn't cost more than £20-50, you mean no more than £50 ?

    And when you say 14cm rod, is that how far the rod must extend or just the length of it?
  6. Curly Fries

    Thread Starter New Member

    Oct 1, 2015
    I've only built a few basic circuits before, I would like the proximity sensor to sense if anything is within 2 meters straight in front of it, it shouldn't cost over £50, and the actuator only needs to extend to 2 inches. It will be for a small device that if something is in the space 2 meters in front of the proximity sensor the actuator will go and stay down, and if not the actuator will go and stay up. The device is planned to be battery powered. Hope this helps.
  7. MaxHeadRoom


    Jul 18, 2013
    If I understand right you want to sense a distance of 2 meters with a proximity sensor?
    The average hall effect proximity is not capable of measuring this distance, you would either have to make an extension with a flag that would cover the Prox, or go some other technology such as retro-reflective etc.