tuning fork oscillator

Discussion in 'General Electronics Chat' started by kurtruk, Oct 28, 2012.

  1. kurtruk

    Thread Starter Member

    Aug 26, 2012
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    I am attempting to make a 1Hz signal for a clock. I have found a 32.768KHz tuning fork oscillator. Do I just apply voltage to one lead of the oscillator and then the other lead will put out a 32.768Khz signal which I can divide down to a 1Hz signal.

    I am aslo wondering about the drive level. The datasheets say it is 1mW. I have a 5V power supply already so I am thinking it would just use 200uA (P=IV .001=5X0.0002)

    So in short:

    1. how do i make a 1hz signal out of a tuning fork oscillator and some counters.

    2. do I need to do anything to sustain the 1mW drive level?

    Thanks in advance. :)
     
  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    No you can´t simply plug one pin to 5V and expect clock coming out the other pin. You need to build and oscillator, typically around an invertor. But since you want to divide the clock anyway, you can use a 4060 to do both. See here http://www.doctronics.co.uk/4060.htm
     
  3. ScottWang

    Moderator

    Aug 23, 2012
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  4. atferrari

    AAC Fanatic!

    Jan 6, 2004
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    Have you found a circuit, the actual chip or just a datasheet?
     
  5. kurtruk

    Thread Starter Member

    Aug 26, 2012
    140
    6
    Is there a way I can use only one ic? I'd like to use through hole components so another whole counter seems wasteful.


    In response to atferrari who said Have you found a circuit, the actual chip or just a datasheet?

    A crystal I think. Here's the datasheet:
    http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_325244_-1
     
  6. ScottWang

    Moderator

    Aug 23, 2012
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    If you can find only one IC to generate 1Hz, please let me know, thanks.

    I used the circuit for a long time.
    [​IMG]
     
  7. MrChips

    Moderator

    Oct 2, 2009
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    You can do it with a special function RTC chip such as a ISL1208 but I would rather use a single MCU chip. Both use a 32768Hz crystal.
     
    Last edited: Oct 29, 2012
  8. takao21203

    Distinguished Member

    Apr 28, 2012
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    PIC 16F54. Does not cost much. And you can program it to replace counters, gates, decoders, oscillators, etc.

    Indeed I have many of these around here.

    I could get fuzzy to build NE555 blink circuits, or more complex circuit from logic gates. But I have moved to the next step: Use small PICs to build circuits which can connect to USB.

    I paid about 50 cents for my 16F54 chips.
     
  9. ScottWang

    Moderator

    Aug 23, 2012
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    If you can write a program to the mcu, that is a easy way to generate 1 Hz, it just send a Hi(1) to the I/O port and call a delay subroutine, and then send a Lo(0) to the I/O port and call a delay subroutine, and then doing the loop from where you start it.

    As takao21203 mentioned PIC16F54, or it's family's mcu, or if you can write a AT89C2051, it is also a easy way.
     
  10. takao21203

    Distinguished Member

    Apr 28, 2012
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    A MCU Flash writer is a small investment these days. Atmel USB programmers only cost $10, while a PICKIT3 costs $30 to $50 (depends if you use a clone). You don't neccessarily need a developement kit or evalution board.
     
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