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Police flasher project?

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by marvel6869, Dec 13, 2009.

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  1. marvel6869

    marvel6869 New Member

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    do ya have a pcb layout for this flasher....:D
     
  2. Boncuk

    Boncuk New Member

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    Nope! It's not more proof than mine, which you don't accept. :D

    I normally simulate circuits or parts thereof using Proteus ISIS before designing the circuit board. The actually built circuits either proved the positive simulation results or the flaws (as already shown during simulation).

    On the other hand it is a matter of politeness to prove a statement, and not force others to prove your statement was wrong.

    Your statement clearly said: "That circuit won't work."

    So it's your turn to prove your statement!

    My proof is as follows:

    counter output H, timer output H - UB=0.872017V,
    counter output H, timer output L - UB=0.372356V, which turns the transistor off.

    Refer to the voltage probes at the base resistor shown in the attached simulation screenshots.

    Boncuk
     

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    Last edited: Dec 15, 2009
  3. Boncuk

    Boncuk New Member

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    Hi,

    here is a very simple circuit. Flashing rate is variable in a wide range.

    Just flip S1 left and right at the desired flash rate. :D
     

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  4. dave

    Dave New Member

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  5. marvel6869

    marvel6869 New Member

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    hehehehe :d what i mean sir that the circuit would not be so complex to assemble :d
     
  6. colin55

    colin55 Well-Known Member

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    Yes, Boncuk, your circuit will work. Build 10,000 of them and I will buy them.
     
  7. Boncuk

    Boncuk New Member

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    Don't you require a quote before "ordering"? :confused:

    How much lead time do you want? :rolleyes:
     
  8. Boncuk

    Boncuk New Member

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    If you wish I will provide a PCB layout design.

    Before I do that I will build the circuit on a breadboard to recheck the simulation results.

    Assembling is not complex. Even trained monkeys can do it. :)

    Boncuk
     
  9. marvel6869

    marvel6869 New Member

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    please can you give mi a pcb lay out.. i really like it....:D
     
  10. colin55

    colin55 Well-Known Member

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    I thought that even a trained monkey could see the cirucit will not work.
     
  11. audioguru

    audioguru Well-Known Member Most Helpful Member

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    The circuit with the CD4017 doesn't flash the LED four times because its outputs Q0 to Q3 light the LED continuously then it turns off for two clock cycles before it is reset.

    The diode connected to the base of the transistor won't turn it off but it might cause the LED to dim slightly. A Schottky diode might work if it is not too cold.
     
  12. colin55

    colin55 Well-Known Member

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    A trained monkey would use a Schottky diode. But, then again, he might say the voltage drops of the diode and the low from the 555 necessitates a voltage divider on the base of the buffer transistor. Trained monkeys are very smart, you know.
    In the meantime I have put it on my website, under: Spot The Mistake, to help my readers design circuits that WORK.
     
    Last edited: Dec 16, 2009
  13. Boncuk

    Boncuk New Member

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    Whatever turns you on!
     
  14. Mr RB

    Mr RB Well-Known Member

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    You guys are so funny. :D This thread reads like train wreck in slow motion. ;)
     
  15. Boncuk

    Boncuk New Member

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    I'd tend to say it has turned in a kind of religious war. :D
     
  16. Boncuk

    Boncuk New Member

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    Nobody asked for four flashes, just three. That's exactly what it does.
     
  17. Boncuk

    Boncuk New Member

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    Recall your yesterday's post:

    Now, where is the truth?
     
  18. marvel6869

    marvel6869 New Member

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    mr BOncuk you mean dual flash like twice on R & Twice on the L.

    you mean this one from this video --->>>>Police Emergency Flasher - VidoEmo - Emotional Video Unity
     
  19. Boncuk

    Boncuk New Member

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    Hi Marvel,

    exactly that with the difference that my circuit uses two LEDs to flash alternating.

    It's no problem to add more LEDs, but the design must be changed for higher current transistor drivers for the LEDs.

    A 9V Alkali battery won't do the job for long. In the video 12 LEDs per channel are used. Blue LEDs normally have a forward voltage of 3.5V, which means 6 parallel strings of two series LEDs must be used. The current flow will be ~120mA at full power, depleting the battery quickly.

    I can't build the three flasher circuit at this time since I don't have a 4017 on hand. Local shops do not provide CMOS ICs and I must travel to Bangkok to get some.

    Boncuk
     
  20. colin55

    colin55 Well-Known Member

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    The man in the corner-store, in the electronics market, has FutureKit kits and one of the kits will have a 4017.

    And there are lots of shops there that specialise in chips, chips, chips. just nearby.
    Build it and you will see why it doesn't work.
     
  21. marvel6869

    marvel6869 New Member

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    thank you alot. now the next challeng will be building a PCBLAYOUT :D;)
     
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