Timer Card ( Help )

Discussion in 'General Electronics Chat' started by icemanz, May 8, 2015.

  1. icemanz

    Thread Starter New Member

    May 8, 2015
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    Can anyone help me out with this problem? i wanna install a photo beam on site A

    If a vehicle stop at site A i want my timer card to do ...something like

    If Object block the photo beam it will activate the timer card and if the time timeout at 60sec it will trigger my siren if before 60 sec the odject unblock my photo beam the timer card will reset the 60second countdown .. any idea how to built this card?
     
  2. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    What you want is called a retriggerable monostable with a 60 second period. As long as the input changes back to the normal stage before the 60 seconds times out, the output never changes. If the input is in the other state for more than 60 seconds, the output changes and activates something like a siren. Two questions:

    1. Does the siren stay on even after the blockage is removed and has to be reset manually, or do you want the siren to end as soon as the blockage moves? In the latter case, the siren might be on only for 1 second.

    2. Do the photo beam circuits and siren already exist, of are they part of this project? If they already exist, what signal does the photo beam produce and what signal does the siren require (voltage levels, currents, etc.)?

    If, for example, the photo beam puts out a 5 V level when clear and 0 V when blocked, and the siren requires a low level to activate it, the timer circuit can be done with 1 capacitor, 2 transistors, and 4 resistors. Or a 555 circuit, or an LM393 comparator circuit.

    ak
     
  3. icemanz

    Thread Starter New Member

    May 8, 2015
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    oh i see..cool .. i want the time can be adjustable

    1. after blockage the siren will deactivated and reset automatic ..
    2. Its new projectand before i start i need this timer system first . the voltage for the photo beam is 10.8V -25V DC ( non polarity )

    this is the photo beam spec

    ModelPB-30SPB-60S
    Protection range30m60m
    Detection methodSimultaneous breaking of 2 beams
    Infrared beamDouble modulation pulsed beams by LED
    Response time50 ~ 700mS
    Supply voltageDC 10.8 ~ 25VDC(Non-polarity)
    CurrentMax. 57mA
    LEDTx : Power(Green LED), Rx : Sensitivity good (Green LED),
    When an alram is initiated (Red LED)
    Alarm outputDry contact relay output(N.C/N.O),
    Delay time: 2sec(±0.5sec) AC/DC 30V 1A
    Tamper outputDry contact relay output form N.C(Rx only), Contact action:
    Activated when cover is deteached, Contact capacity : 30V
    (AC/DC) 1A or Less
    Temperature-20℃ ~ 60℃
    Beam AdjustmentHorizontal:190˚(±95˚), Vertical:20˚(±10˚)
    Mounting siteIndoor/Outdoor
    MaterialCover : PC resin, Base : ABS resin
    Dimension63 x 163 x 75mm (WxHxD)
    WeightRx : 330g, Tx : 315g
    FunctionMonitor jack output, Frost proof cover
    IP ratingIP 44
    OptionPole attachment(2pcs/set, Pole size: : Φ38~44mm),
    Transmitter tamper S/W, IP 54
     
  4. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Half way there. What are the specs on the siren? Particularly, the operating voltage and the input.

    ak
     
  5. icemanz

    Thread Starter New Member

    May 8, 2015
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    Just normal siren that need 12V voltage
     
  6. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Almost there...

    Does the siren have a control input, or just + and - power inputs?

    Do you have a make and model number for the siren?

    It looks like everything can be powered by 12 VDC. Is there going to be a single system 12VDC power supply, or separate power supplies for the photo beam and the siren?

    How is this going to be packaged and installed? Indoors, outdoors, etc.

    ak
     
  7. icemanz

    Thread Starter New Member

    May 8, 2015
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    seperate power supply for the board and all its 12V
     
  8. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Does the siren have a control input, or just + and - power inputs?

    Do you have a make and model number for the siren?

    How is this going to be packaged and installed? Indoors, outdoors, etc.
     
  9. icemanz

    Thread Starter New Member

    May 8, 2015
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    0
    It only has + and - .. And it's for indoor
     
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