Photoelectric help

Discussion in 'The Projects Forum' started by Poetsmantra, Apr 29, 2010.

  1. Poetsmantra

    Thread Starter New Member

    Apr 29, 2010
    3
    0
    Hey everyone, I have a project in the works in which I am stuck on the schematic design. I will try to explain this the best I can...

    Project background information:
    What started this project was the simple fact that I became fed up with cleaning up beer bottles and pop cans after a social get together at my house.
    In my kitchen island, I built a bottle/can return chute for recylcables. This chute (4" PVC) goes down to the basement and ends in a large container to hold recycled cans.

    What I am trying to do here is design a simple system/circuit to tell me when the container is full. What I am going to use as an identifier is a "RED/GREEN/BLUE" combination LED. On this particular LED, I am only going to use the "GREEN" for empty, and "RED" for full.

    I would like to use some sort of photoelectric sensor to sit atop the container and measure it's empty/full state. When the can height passes the sensor, it is to change the led from "GREEN" to "RED." I don't have much knowledge in photoelectronics which is why I am here today.

    Also, I have a bright 2600MCD "BLUE" LED in which is going to light up the chute entrance when the door is pulled down to insert a can (will be triggered by a magnetic reed switch of some sorts).

    I would like to use a 12V 500ma power source for this project (same power source for both the sensor application and the lighting of the chute entrance).

    I have included some pictures of the material and project I am working with. I would appreciate any and all help!
     
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Do you really need to know if container is empty? Do you want to modify container or just put a beam break sensor near the top ? Just checked a bright white LED, 20 ma, 3.3V & a one cm light dependent resistor for range. In dimly lit room, reliably had 10 to 1 resistance change at 4 ft, easily detected with a comparator/ LED driver.
     
  3. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    I think this will work: R2 LDR, about 1 cm, 100Ω- .5megΩ dark. LM383, dual comparator, R3 depends somewhat on LDR selected, R4 5k to 100k pot. 600 Ω s may vary depending on LED ratings. Need information on LED. Last two 4.7 resistors are 4.7K ohm.
     
    Last edited: May 5, 2010
  4. Markd77

    Senior Member

    Sep 7, 2009
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    LM383? Doesn't sound right to me.
    Apart from that it looks nice.
    If you put the chute going vertically and finishing a few inches above, when it is full the last can will block the bottom of the chute, which should be easy to measure.
     
  5. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Markd77- right on, should have removed paperclip covering up the 9, it is LM 393. Maybe should have kept 383, added speaker & mic so we could haer the loud CLUNK as the cans fall.
     
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