LED sequencer w/motion sensor activator

Discussion in 'The Projects Forum' started by allenpitts, Feb 26, 2011.

  1. allenpitts

    Thread Starter Active Member

    Feb 26, 2011
    77
    7
    Good afternoon All About Circuits,
    Been experimenting with LED sequencers such as
    http://www.chaneyelectronicsstore.com/servlet/the-214/Sequential-LED-Flasher-Kit/Detail
    (which seems to be very similar to
    http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
    found on this site)
    and
    the Velleman Wheel of Fortune circuit
    http://www.youtube.com/watch?v=leWdcgsAgo0
    Another concept is
    http://wild-bohemian.com/electronics/chr-info.htm
    Seeking out ways of combining and mulitplying these flashers and
    using them in clear lucite objects to create a sort of eye candy.
    Am willing to provide compensation to someone who could help me
    learn and experiement with this.
    But the immediate need is a way to make the project kit circuits come on
    when approached so they don't have to be turned on by the viewer.
    I was hoping to do this with a motion decector of type
    http://www.radioshack.com/product/index.jsp?productId=3506460
    But the specs on these always talk about connecting the
    sensor to a 'control panel' so not sure how to use the motion detector
    (which is usually part of a security system which I believe runs
    on 48 volts dc) to activate these circuits.
    Any ideas?
    Allen in Dallas
     
  2. nerdegutta

    Moderator

    Dec 15, 2009
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  3. Wendy

    Moderator

    Mar 24, 2008
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  4. allenpitts

    Thread Starter Active Member

    Feb 26, 2011
    77
    7
    Good afternoon Mr. Marsden and Nerdegutta,

    Activation methods, other than the motion detector seem superior
    if for no other reason than one could use a single low voltage power supply,like a wall wart from another electronic device, instead of introducing a 48 volt supply used for a security system control panel.
    A site was visited
    http://coilgunpower.com/picproj/444cube.php
    where a guy is using sound to activate a device
    http://tinkerlog.com/category/sound/ so that the viewer could activate the
    device by clapping hands. The concept is that the viewer would not have to have any special knowledge or turn a switch for the device to begin doing its thing.
    I think IR would be great because the viewer would not have do any thing
    correct? Can I Ir be done in the 5 to 15 volt range?

    'LEDs, 555s, Flashers, and Light Chasers' has been read and reread until parts of it are memorized.

    Started with the 2 NPN transistor show on the left at
    http://reprise.com/host/circuits/transistor_flasher.asp
    Believe it or not I got hung up by the fact that in the schematic where the lines crossed
    I thought that every where the lines crossed the wires were connected. I redrew
    the schematic
    http://www.allenpitts.com/electronics/NPN_Two_Transistor Flasher_b.gif
    in the URL above with little semi-circles to emphasize that fact
    although the line crossed they were not connected.
    The result was
    http://www.allenpitts.com/electronics/NPN_Two_Transistor Flasher_c.gif
    The next stop from there
    http://www.doctronics.co.uk/4017.htm
    which is similar to your 'LEDs, 555s, Flashers, and Light Chasers'
    and then
    http://www.youtube.com/watch?v=XciBYUlwxls
    and
    http://www.youtube.com/watch?v=_cLLyfop3QI&feature=related
    So the first circuits were discreet components, then ICs and I can
    quickly see a move to programmable ICs.
    But would like to see how far sequencing can be taken without
    PICs.
    I live in a part of north Dallas called Preston Hollow. Not sure
    how well you know Dallas, but if you know where Hillcrest High
    School is, I live approximately behind Hillcrest High School
    where my son plays football and lacrosse.
    Also experimenting with using flashers like
    http://www.allenpitts.com/electronics/NPN_Two_Transistor Flasher_b.gif
    and/or sequencers to cascade sequencers like
    http://www.chaneyelectronicsstore.com/servlet/the-214/Sequential-LED-Flasher-Kit/Detail
    For instance, we know that in the 2 NPN LED Flasher
    http://www.allenpitts.com/electronics/NPN_Two_Transistor Flasher_b.gif
    the 39k resistor controls the duty cycle so perhaps we could
    increase the value of the 39k resistor and in place of the LEDs one would have the current input
    (where the battery would go) for the Chaney Sequential LED Flasher Kit - C4431. But since the
    470 ohm resistor's primary function is to reduce the current through the LED to keep it from
    overheating, maybe the 470 ohm resistor component could be greatly reduced or eliminated.
    Allen in Dallas
     
  5. Wendy

    Moderator

    Mar 24, 2008
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    You are a bit off on your understanding of LEDs, or at least your phrasing is. The resistor is not to prevent overheating, it is to limit the current to what the LED is rated for. LEDs are first and formost current controlled devices, not voltage. So while the resistor on an LED does indeed prevent overheating, the LED will burn out long before it gets hot if you allow too much current to flow though it. It is a specification thing. A more correct word might be biasing, which also applies in spades to transistors.
     
  6. nerdegutta

    Moderator

    Dec 15, 2009
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  7. allenpitts

    Thread Starter Active Member

    Feb 26, 2011
    77
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    Good morning All About Circuits,
    Experimenting with led flasher and sequencing circuits.
    Have built several like the Velleman Wheel of Fortune
    www.allenpitts.com\Wheel_of_Fortune_E_110126.gif
    http://www.youtube.com/watch?v=leWdc...DFEB9C0AD9C49E
    and the Chaney sequencer which is similar to
    http://www.chaneyelectronicsstore.co...her-Kit/Detail
    http://www.allenpitts.com/electronics/555/4017-7.gif
    and this forum's excellent
    http://www.allaboutcircuits.com/vol_6/chpt_7/6.html

    These are fun to look at but a draw back is that one must have special
    knowledge (although it is only where the switch is and how to operater it)
    for the viewer to see the effect. In a query to this forum Nerdegutta
    suggested Mondotronics
    http://www.jameco.com/Jameco/Products/ProdDS/358580.pdf
    Modulated Infrared Reflective Detector (MIRD) Schematic:
    http://www.allenpitts.com/electronic...e_Detector.gif
    as a means of activation with only the presence of the viewer
    to activate the circuit.
    So the challenge, before I spend my twenty bucks on the infrared
    detector, is to figure out how to turn the LED sequencer circuits
    on using the infrared detector.
    The Wheel of Fortune takes a momentary switch as shown in the schematic is the GIF
    listed above. I think it is a normally off momentary switch so I think
    a pulse from a 555 timer acting in the monostable mode would get the
    job done. True? Do momentary switches come in normally off and normally on types?
    But that is more speculation since the project I am actually trying to
    master is the ten LED sequencer shown at All About Circuits. The activating switch in the
    http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
    at All About Circuits, the Chaney and the 4017-7 above would be a simple on off switch where
    in the 4017 portion of the circuit that is connceted to the LEDs would be connected to the voltage continually and the voltage
    connection to the 555 would be switched. In this case the 555 would be
    operating in bistable mode and turning the 4017s on for a set period of time as the 555 goes between triggered and reset.
    So I went looking for a circuit to operate the LED sequencer when I happily discovered that
    there was already 555 activator in all of these the 4017 cicuits.
    The most important question is about my understanding of 555s. I believe
    the 555 in the 4017 circuits listed above is in bistable mode as in
    http://www.allenpitts.com/electronics/555/tim42.gif
    and the resistors R1 and R2 control how long the timer is off and how long it is on. True?
    If all that is true the question is how to the MIRD (infrared detector)to turn on the 555 timer operating
    in bistable mode whixh would then activate the
    sequencer. In the MIRD schematic above
    there is a 'Signal Out' node. Is the solution as simpla as connecting the
    Signal Out on the MIRD to pin 2 (trigger) and pin 6 (threshold) of
    the 555 timer?
    Thanks.
    Allen in Dallas
     
  8. nerdegutta

    Moderator

    Dec 15, 2009
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    It depends on the signal out of the IR device.

    My imidiate thought was that you assemble the 555 in monostable and hook the yellow (it is yellow in the datasheet), signal cable to the pin 2 (trigger) of the 555. ..and voila, you have an IR trigger... If it was that simple, it would be awsome...:D
     
  9. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    AAC member, pbalien73 had good results with PIR motion control of lighting a diorama using Quorum A-160 PIR [ The Electronic Goldmine $14.95 ], about same as RS unit.
     
  10. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    I would personally steer you away from this approach, and rather direct you toward the PIR devices;
    http://www.radioshack.com/product/index.jsp?productId=2906724
    http://www.jameco.com/Jameco/Products/ProdDS/2082927.pdf
     
    Last edited: Mar 6, 2011
  11. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    For a smaller, 10 mm, dia PIR, model KC7789M, one supplier- www.electronics123.com similar to RS but 5-12V operation. The RS 276-033 , Parallax 555-28027 has a jumper to select a continuous pulse out for several close spaced activations, where as KC7783 would likely need a 555 to combine pulses into one .
    How many LEDs in proposed display- any configuration settled on yet??
     
    Last edited: Mar 7, 2011
  12. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Might want to check post by tracecom, What makes a flickering LED flicker, in Chat.
     
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