Adjustable strobe circuit for multiple(6-10) Luxeon rebel LEDs

Discussion in 'The Projects Forum' started by Straykiller, Aug 26, 2012.

  1. Straykiller

    Thread Starter New Member

    Aug 26, 2012
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    Hello I am pretty much a beginner when it comes to electronics so please bear with me. Im working on a project and after searching the internet for days not seeing a whole lot that could help me i found this forum and i hope some of the knowledgeable members here can help me with my project.

    Here is what im working on, i would like to be able to strobe 6 to 10 luxeon rebel led running at 350mA at 60Hz with a pot that can be turned up or down to adjust the strobe rate. I was hoping to use a Xitanium 120VAC, 12W, 700mA Driver to power all of the leds and 350mA.

    http://www.luxeonstar.com/Xitanium-120VAC-12W-700mA-Driver-p/led120a0700c24f.htm


    While originally i thought i could use a 555 chip to strobe each light i have found out that the chip can handle at most 200mA. Would it be possible to have the 555 chip strobe the led driver instead? Could i possibly run the 555 circuit separately and use it that way? I ran across this video that looks like thats whats being done. Unfortunately there is no information on the circuit.

    http://www.youtube.com/watch?v=cRCRuFNX54g

    If someone wouldn't mind sharing with me how i can possibly do this i would greatly appreciate it (sorry I am an extreme noob)... also if anyone knows how to do this and would be willing to help me design it i would be more than happy compensate you for your troubles if its allowed if not please let me know and ill remove this sentence from my post.

    Thanks i really appreciate any help i get.

    Take care,

    Justin
     
  2. KJ6EAD

    Senior Member

    Apr 30, 2011
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  3. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    The circuitry used in the video you linked to is very easy to duplicate, however it won't drive many high power LED's. The circuit is just a NE555 in an astable configuration with the output of the NE555 supplying base current to a 2N3904 which switches the power to the LED. Although the circuit in the video is not adjustable, adding that feature is doable.

    Here is an example of an NE555 used in an astable configuration. In the schematic shown, the NE555 is alternately flashing two ordinary LED's. In your application, you would probably use a potentiometer in series with R1 to adjust the flash rate. The output from the NE555 would be used to control the driver for your LED's.
     
    Last edited: Aug 26, 2012
  4. Straykiller

    Thread Starter New Member

    Aug 26, 2012
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    thanks for your help, with this BuckPuck how would i connect it to the 555 circuit? after the circuit is made would i just connect the control pin on the Led Driver to pin 3 on the 555 chip? thanks

    Also since that driver has a control pin i could control it with an I/O pin on a micro controller if i wanted to right? no saying that i want to but im just curious.

    Thanks you for posting those pictures i really appreciate it im going to try to duplicate it tomorrow and play around with it. if i don't want it to alternate 2 leds can i just disconnect one?


    Thanks again to both of you for taking the time to help.
     
  5. KJ6EAD

    Senior Member

    Apr 30, 2011
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    Yes to both questions. The control pin is a voltage input. It controls the driver's output current in the manner described in the BuckPuck datasheet. Be sure to download and read it.
     
  6. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    Yes, you could disconnect either one. LED 1 is on when pin 3 is high and LED 2 is on when pin 3 is low. For your project, you will likely want a high output from pin 3, so I would recommend you disconnect R 5 and LED 2. I think it would be worthwhile for you to build this circuit and experiment with it. Once you get it working as is, you can begin to make changes one at a time to move toward the effect that you want, and ultimately connect it to whatever driver circuit that you use.

    ETA: SW 1 is a reset switch, which you probably don't need. You can take it off, but leave R 3 connected between pin 4 and +V.
     
    Last edited: Aug 27, 2012
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