Sychronising flashing lights

Discussion in 'The Projects Forum' started by Buzzer25, Apr 3, 2012.

  1. Buzzer25

    Thread Starter New Member

    Apr 3, 2012
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    I am currently trying to work out a way of making a set of flashing xenon lamps, (only connected by 24v and 0v wires) flash at exactly the same time at a rate of 1 flash per second. I dont want to have to use a 3rd wire to make it possible.
    I currently hvae a working circuit for the flashing lamps, individually, but making them flash together is proving to be a bit more difficult.

    Does anyone know a way of being able to either get them to sync correctly, or possibly being able to send a small "boot pulse" type signal down the 0v line?

    Any help would be really great.
     
    Last edited: Apr 3, 2012
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Can u show us ur xenon lamp ?
     
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
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    In photography, one flash (master) is controlled by the camera and all others (slaves) are triggered by sensing the flash from the master. If something like that could work for you then you'd need to modify all but one of your strobes.
     
  4. Buzzer25

    Thread Starter New Member

    Apr 3, 2012
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    The problem with using the photography method is that the beacons may not be able to see each other.

    At present I am using a 40106 with an RC stage to give a kind of boot pulse, and using a crystal oscillator to give the 1 flash per second. The only way I have found so far is using precision components but they are a lot more expensive and you cant get all the values I want.

    It has been suggested to turn the power off for 50ms and on for 950ms, but the spec says once they are turned on the power is constant for 1 hour.
     
  5. MrChips

    Moderator

    Oct 2, 2009
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    Can you post a circuit diagram of the beacon as well as the power source?

    You may be able to do this by putting a sync signal on the 24v power line.
     
  6. Buzzer25

    Thread Starter New Member

    Apr 3, 2012
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    Part of the circuit is shown below, for some reason it wouldnt let me copy anymore. From the 4060, it goes to a 4013 D type flip flop giving a signal to the beacon.

    The power is just a normal battery, which we have no control over, only the fact that it is connected to the beacons.
     
  7. MrChips

    Moderator

    Oct 2, 2009
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    I would skip the precision components. You will never get the flashes in sync.
    I would modify the 24v supply to put a 1v sync on the supply line.
    Then AC couple this signal off the supply line and trigger the flash.
    This would eliminate all the digital components.
     
  8. Buzzer25

    Thread Starter New Member

    Apr 3, 2012
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    Unfortunately I have no control at all over the 24v supply, so I cant modify it in any way. Would your method still be possibly? Maybe by creating some kind of feed back into the 24v supply?

    The 24v DC is being supplied from a 3rd party who have already made the supply and cannot/will not change it.
     
  9. MrChips

    Moderator

    Oct 2, 2009
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    How much current does each strobe require?
    You can add the 1V sync circuitry as an add on after the 24V supply.
     
  10. Buzzer25

    Thread Starter New Member

    Apr 3, 2012
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    They are using no more than 400mA i think, (its more likely to be around the 300mA mark) but it can vary, I have had some using loads more current but then I found I had a faulty tube.
     
  11. RiJoRI

    Well-Known Member

    Aug 15, 2007
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    Is there a reason you can not use a brute force method, e.g., use a relay to toggle the power to the lamps? Or, there may be a synchronizer module available as is used with alarm systems. I know there is one for fire alarms, but those have a cadence of flash, flash, flash, pause.

    --Rich
     
  12. Buzzer25

    Thread Starter New Member

    Apr 3, 2012
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    I wish I could use a relay, but I dont have access to the power supply to fit one, and if I put one on each lamp then I would be back to having the same initial problem.
     
  13. MrChips

    Moderator

    Oct 2, 2009
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    I would add one or two diode rectifiers in series with the 24V supply and bridge the diodes with a power MOSFET. Most of the time the MOSFET will be enabled to provide full voltage to the strobes. Once every second, the MOSFET will be turned off for about 1mS to generate a drop in the 24V supply line.

    This sync signal can be detected at each strobe to trigger the flash.
     
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