Infrared sensor with timer with On/Off function

Discussion in 'General Electronics Chat' started by cymonesays, Sep 1, 2010.

  1. cymonesays

    Thread Starter New Member

    Aug 31, 2010
    Hi There,

    I'm working on a project with my son and I, unfortunately, have very little knowledge of electronic assembly. I have a very good knowledge of computers, networking and can recognize electronic components fairly well (capacitors, resistors, transistors, ICs + values and other simple stuff). I can solder too, but I don't know how to build circuits. Please help us.

    Overall Objective:
    We'd like an infrared sensor or two that crisscross each other to detect when a radio controlled car enters a square perimeter of about 5x5 feet. Once the car is detected to have entered this space (anywhere within it) the gate starts its travel upward to open then stops.

    The module should perform the following:
    The circuit should pick up a motion within this 5x5 foot entry area using an infrared mesh spread across the area floor with no reflectors or any other items on the floor of the perimeter that could cause the car to stumble or catch. I'm open to other technologies other than infrared depending on your recommendations.

    Once motion is detected a timer should be triggered to start counting for about 20 - 30 seconds (adjustable). When the motion is detected, and the counter is started, the circuit should send out a signal to ease ON a HVAC motor that lifts the gate. When the timer stops counting it should send out a new signal to ease out or turn OFF the HVAC motor so the gate stops lifting up. The gate can then stay up. Now, if his friend's car enters the 5x5 area the timer should reset and start the count from the beginning again until it reaches 20 - 30 seconds (adjustable), resulting in the gate stopping higher up than if only his car would have entered alone.

    I hope that makes sense. Thank you so much for your help.
  2. marshallf3

    Well-Known Member

    Jul 26, 2010
    Can you imbed a loop of wire in or under the floor then put magnets on the bottoms of the cars?
  3. cymonesays

    Thread Starter New Member

    Aug 31, 2010
    Thanks so much for the quick idea, but I'm afraid I can't dig into the flooring. It's solid concrete leading into the back side of the garage. Clever thought, though! We would also have to modify his friend's giant R/C car and I don't know that he'd be willing.