Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Making Motion Sensors?

  1. May 22, 2008 #1
    Hello everyone,
    I intend to make a "Digital bus arrival information panel".The circuit will be built into my product.So when a bus leaves,the sensors activates a bulb to flash for a time period(e.g 15 mins).Here is a picture similar to my idea:


    So the questions are:
    1.How do I make sensors that work and make each work individually in my circuit?
    2.How do I make the bulbs "timed" for 15 mins after each individual sensor is being activated?

    I have little experience in building a circuit(is a resistor needed?What is a blahblahblah) and hope someone would help me in this.Thank you.
    Last edited: May 22, 2008
  2. jcsd
  3. May 22, 2008 #2


    User Avatar

    Staff: Mentor

    What class is this project for? What background do you have so far? What year in college are you?

    Welcome to the PF, BTW.
  4. May 22, 2008 #3
    "1.How do I make sensors that work and make each work individually in my circuit?"

    I would suggest looking at RFID tags. They're pretty cheap, widely available, and relatively simple. For question 2. You could use the RFID tags to trigger a timing circuit that throws a relay off at your time limit.

    Sorry for being so vague.
  5. May 22, 2008 #4
    Well,I'm from another country,I'm taking Design and Technology,knows limited(Basic) stuff about electronics.I currently know things like LED,anode those simple stuff.I'm 15.

    Thanks for the welcome.
  6. May 22, 2008 #5
    Thanks for the useful information.BTW What parts do I have to purchase for this project?
  7. May 23, 2008 #6
    Sorry, I was just suggesting that as a good way to start. I have yet to build anything practical (aside from Marx Generator, Van de Graaf, coil gun, etc).

    Well, if it wouldn't break any local laws or interfere with any transmissions, you could simply set up a lower power (maybe 100mW) oscillator (powered off the battery) with a different frequency on each bus.

    There's tons and tons of oscillators and I don't know which one would suit you best.

    Now, on your display board have receivers for each of the buses. This way is far from efficient though. It's very redundant as each oscillator is essentially the same with adjusted parameters; the same goes for the receivers.
    Last edited: May 23, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook