555 voltage tripler

Discussion in 'The Projects Forum' started by Skfir, Jan 3, 2013.

  1. Skfir

    Thread Starter Active Member

    Aug 19, 2010
    135
    4
    Hello guyz! Just wanted to ask, perhaps someone knows, if it is possible to make a voltage tripler on a 555 timer? Again the simplest circuit, gives about 400v. Can I make say 400*3=1200? Doublers work just fine, but since we have one polar power supply here, common tripler schematics do not work. So please help with advice.
     
  2. k7elp60

    Senior Member

    Nov 4, 2008
    478
    69
    How much current do you need at 1200V. The 555 would work as an oscillator to drive a transistor and a transformer to get the 1200V.
     
  3. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Ever thought about using the flash circuit from a disposable camera?
     
  4. Skfir

    Thread Starter Active Member

    Aug 19, 2010
    135
    4
    In my schematic there is no transformer, but a coil. I need a very very small current, about a 0.5 nA. Disposable camera will not work here, because I ne the coefficient of multiplication to be exactly 3.
     
  5. Skfir

    Thread Starter Active Member

    Aug 19, 2010
    135
    4
    In my schematic there is no transformer, but a coil. I need a very very small current, about a 0.5 nA. Disposable camera will not work here, because I ne the coefficient of multiplication to be exactly 3.
     
  6. Brownout

    Well-Known Member

    Jan 10, 2012
    2,375
    998
    I was looking at some tripler circuits, and I think they might work, though you may not get 3X output. You might try a quadrupler or higher. I think the multiplier ckts should work on a uni-polar supply, but might need to be higher than normal.
     
  7. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    Attached is one I did. Output ~800V. For 1200V you need to add another diode/capacitor (2 diodes and 2 capacitors) multiplier stage. Also, increase the voltage ratings on the diodes and capacitors.

    Ken
     
  8. Skfir

    Thread Starter Active Member

    Aug 19, 2010
    135
    4
    Thank you people! I appreciate so much your help.
     
  9. Skfir

    Thread Starter Active Member

    Aug 19, 2010
    135
    4
    Just a small addition to the subject: the schematic which is attached above works very fine. And thanks again. However, after doing some research I found out that in spite of an apparent similarity, the multiplier for a single pole power supply needs some small additional tweak for better performance and less parts used. For some reason I could only find this information in Russian internet, nevertheless I will post the link to the article and the most important, schematic for the multiplier. The only difference is mere removal of the first couple capacitor-diode.

    http://nauchebe.net/2010/06/umnozhiteli-napryazheniya-sxema/#comments
     
    Last edited: Jan 6, 2013
    Brownout likes this.
  10. Skfir

    Thread Starter Active Member

    Aug 19, 2010
    135
    4
    One more addition. I will include some hints for correct calculation of necessary capacitance translated from that Russian article. So here is the formula for calculating the last (the most right) capacitor: C= [I(out)*T(length of the charging input pulse in micro seconds)]/V(amplitude of output pulsations). One more thing is increase of capacitance of each capacitor from right to left. This is because the first capacitor has to feed all the others. So in order to maximize performance we should multiply the value od the last capacitor (see the formula above) on the coefficient which increases the more we go to the left. Look at the picture attached. Next to each capacitor you will see a number. The number is the coefficient on which the capacitance of the output capacitor must be multiplied in order to provide maximum performance. As you can see the more we go to the input of the multiplier the bigger capacitance is required.Most probably everybody here knows these tricks, but just in case there are some greeners here like myself this information might be of use.
     
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