time shift pulses (see picture)

Discussion in 'The Projects Forum' started by katonidas, Sep 6, 2012.

  1. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    Can't success to do this (image attached) . The wave original is the upper one and it is like 2 milisec and 10 % dutycycle.
    I want to move it 10 milisec approximately.
    thanks

    Note : i tried simple inverters with RC but ics not usefull here.
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    What you want is either a delay line or an n-stage shift register.
     
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  3. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    it is an analog circuit,
    this pulse is generated via 555 timer.
    I wanted to use shift register ( D-flip flops ?? ) but what can i put in the clock input of the shift register?
    I don;t have another clock or system clock, not digital system.

    Thanks
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    Then an analog delay line is your only option. Good luck finding one for the time delay you need.
     
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  5. crutschow

    Expert

    Mar 14, 2008
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    It's difficult to delay a 2ms pulse by 10ms with analog only. You need some sort of temporary memory which is most easily provided by digital circuits. You can generate a clock for this purpose using another 555 in an astable circuit.

    Does the frequency or duty-cycle of the signal vary?
     
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  6. ScottWang

    Moderator

    Aug 23, 2012
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    If I'm not misunderstanding what you mean, I designed a circuit, you can check it, does it match your need?
    R1,C1 : Differential circuit for CD4013 Q1 preset to Hi level, it means that the time delay has completed, you can change the value of R1 and C1, it could be affect the trigger time of Q1(CD4013).

    R2,C2 are for the Q1 of CD4013 power up reset to Low level.

    [​IMG]

    CD4518/CD4520 datasheet.
    http://www.datasheetcatalog.org/datasheets/120/109587_DS.pdf

    MC14518/MC14520 datasheet.
    http://www.datasheetcatalog.org/datasheets2/17/178718_1.pdf

    74HC08 datasheet.
    http://www.datasheetcatalog.org/datasheet/philips/74HC_HCT08_CNV_2.pdf

    CD4013 datasheet.
    http://www.datasheetcatalog.org/datasheets/150/108670_DS.pdf

    By the way, maybe you can talk about what's your purpose of the circuit, probably it has a different method to solve your problem.
     
    Last edited: Sep 7, 2012
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  7. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Are the pulse width and period constant?
     
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  8. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    In order to make it simpler,
    let say no vary.
     
  9. katonidas

    Thread Starter New Member

    Sep 5, 2012
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  10. crutschow

    Expert

    Mar 14, 2008
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    Is that a 2ms period or a 2ms pulse width? What is the frequency of the pulse?
     
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  11. absf

    Senior Member

    Dec 29, 2010
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    Is this the delayed pulses diagram you wanted?

    [​IMG]
     
    Last edited: Sep 8, 2012
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  12. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    I attached a PDF file , there , the Adjustable Amplifier is an OPAMP that you can connect two bits that program the gain (for example G=1 or G=8) and in the input signal i connect a 0.4 precise volt reference .
    Finnaly after all this you can see in the PDF that i make SUM operation (another amplifier or summer) and i would obtain an alternative POSITIVE / NEGATIVE pulse signal.
    The desired signal was drawn in red color.

    Thank you.
     
  13. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    I have explained in the post below .
     
  14. ScottWang

    Moderator

    Aug 23, 2012
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    Did You used Op Amp to adjust the Amplitude of the waveform?(ex:G=1,G=8)

    Orignial Ne555 Clock → 10mS delay time(NE555 Mono) → 2 mS Pulse(Ne555 Mono) → Delay Clock.

    The delay time T formula of NE555 shows on the circuit diagram.

    [​IMG]
     
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  15. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    ScottWang, thanks,
    i will try this in Multisim in a few hours.
    Do you use multisim ? Which program do you use for drawing circuits?

    Do you mean the adjustable amplifier ? I specified in the ORCAD scheme.
     
  16. ScottWang

    Moderator

    Aug 23, 2012
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    >1. Do you use multisim ?

    No.
    When I design the circuit Almost according my experience and EE theories, sometimes if I can't make sure about some circuits or theories, then I will doing the lab to see what's going on.

    >2. Which program do you use for drawing circuits?

    I used the Microsoft paint to draw the circuit, I already draw some basic EE symbols, so it's easy to draw the simple circuits.

    If you can use Microsoft paint, then you can also copy the basic symbols to draw your circuits, I will spend some space time to translate from Chinese to English, and I will also update the basic symbols, after that, I will put them on the resource of this website.

    Windows Paint - Chinese Language Only, you can copy the basic symbols to draw your circuits.
    http://hihand.myweb.hinet.net/prg/eepaint.htm

    >3. Do you mean the adjustable amplifier ? I specified in the ORCAD scheme.

    I means that when we use Op amp to set the Gain, it will affect the amplitude of output voltages.
     
    Last edited: Sep 9, 2012
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  17. crutschow

    Expert

    Mar 14, 2008
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    The 555 triggers on a negative going pulse so you don't want Q2. It will cause U2 to trigger at the start of U1's output pulse instead of at the end of the pulse as needed for the 10ms delay. Just remove R5, R6, and Q2 and connect C4 directly to U1-Q.

    A simulation of the circuit would have spotted that problem. ;)
     
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  18. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    you people answer very quick , i haven;t checked the circuit on simulation . :)
    I hope in the next hours
     
  19. katonidas

    Thread Starter New Member

    Sep 5, 2012
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    Have you checked it ?
     
  20. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    If all the timing parameters are truly fixed, I would use a 555 to generate a 500Hz clock (2mS period), and a 4017 to generate the 2mS pulses at 50Hz.
    Varying the frequency of the 555 will vary the output frequency. The duty cycles will be fixed, and the delayed pulses will be centered exactly between the first ones.

    See attached.
     
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