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I want to build an electronic device but need help

Discussion in 'General Electronics Discussion' started by kornjack, Apr 15, 2015.

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  1. kornjack

    kornjack

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    Apr 15, 2015
    Hello,

    I have limited experience with electronics and just trying to get some ideas on how to build an electronic device that I will describe below. Here are the specs

    Description: The device I want to make is a light that blinks off and on at a set rate and runs off a small battery or can be hard wired.
    • Small gadget the size of a quarter
    • the light is similar or exactly like the light on a cell phones camera
    • it's powered by a battery but has a long life or can be hardwired
    • it blinks at a steady rate maybe once every 5 seconds
    What materials would I need? And about what would it cost me to make? If these requirements are too much or this question is not part of this forum I'll be glad to remove it.

    Thanks in advance
     
  2. donkey

    donkey

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    Feb 26, 2011
  3. HellasTechn

    HellasTechn

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    Apr 14, 2013
    Friend all you need is an LM555 connected as an unstable multivibrator.

    by using SMT components you can easily make it small as a quarter. If not it will still be very small

    Here is the circuit :

    by changing the R1 trimer you can adjust duty cycle and by changing VR trimmer you can adjust frequency.

    P.S. you can use a high luminance LED. the 555 can handle 300ma output current without a problem that should be enough for a very bright LED.

    As power supply you can use a 9v battery.
     

    Attached Files:

    davenn likes this.
  4. kornjack

    kornjack

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    Apr 15, 2015
    Thank you Donkey and HellasTechn for your response. And I apologize for taking so long to reply my laptop died and I finnaly fix it. Donkey the bulb you recommend, this is only the bulb correct? And then I would need to connect it to a battery and encase it?

    HellasTechn: The diagram I am totally lost on but would this be a circuit board with all these little transistor soldered on to it?

    Thanks
     
  5. BobK

    BobK

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    Jan 5, 2010
    There are no transistors in that diagram. There is a chip and some other components.

    When you say "like the light on a cell phone camera", do you mean that bright? These are very bright and use a lot of power. They probably cannot be run from a button battery.

    Bob
     
  6. HellasTechn

    HellasTechn

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    Apr 14, 2013
    Thats right there are no transistors. Only a DIP8 package 555 timer chip, two capacitors and two trimer resistors and a fixed resistor (you mey be able to skip that by selecting apropriate led). The high luminance led's (like cellphone camera flash led's can be driven from a battery (say a 9 volt battery)

    you could use this (5w) LED
    http://www.ebay.com/itm/Hot-White-W...t=LH_DefaultDomain_3&var=&hash=item20e8c3e831

    This circuit is really very simple to build but still it reqires a little experience in soldering and making pcb's in general.

    OR

    if you dont really want to make it yourself here you can buy it ready :

    http://www.ebay.com/itm/5pcs-Duty-C...196?pt=LH_DefaultDomain_0&hash=item35e82734b4
     
  7. kornjack

    kornjack

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    Apr 15, 2015
    Thanks HellasTechn I really appreciate all the info. I am descent with soldering but electronic jargon sometimes escapes me. Could I commission you to build this for me?
     
  8. HellasTechn

    HellasTechn

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    Apr 14, 2013
    I guess you could but i dont really see the point why.

    It is not that i wouldnt like to do this for you but isn't it kind of same thing like ordering it online from say E-bay ?

    Plus shipping to the United States from Greece will take a long time (a month or so).
     
  9. kornjack

    kornjack

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    Apr 15, 2015
    OK Hellas I think I can do this myself but I may need more assistance as I stumble my way through it. I really do appreciate all your help including Donkey's. I will start soon and let you know my progress.

    Thanks very much.
     
  10. HellasTechn

    HellasTechn

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    Apr 14, 2013
    No problem friend. I could lay out the pcb diagram for you (useing pcb express software) and then you could just follow it to make your board. Or you can try doing it yourself if you want to learn. It is really easy just takes time !
     
  11. cjdelphi

    cjdelphi

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    Oct 26, 2011
    regardless if the led is a 5mm consuming 20ma or a 5watt LED, the 555 will do the job, just add a transistor.
     
  12. HellasTechn

    HellasTechn

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    Apr 14, 2013
    Even with a 5 watt LED you dont need a transistor to boost current. like i said a 555 can well handle 300ma (tested) wich is enough current for a 5w led to glow bright.

    I think that with a 9volt battery it should work fine (worse case you add a small value resistor in series with the battery to limit current down to say 300ma).
     
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