Wednesday 13 February 2013

NE555 Voltage Inverter

Here's a cheaper-to-build alternative for MAX1044/ICL7660 voltage inverter charge pump. According to the documentation, this puppy is capable of 30mA of output current, so it'll be enough for any stompbox use. Circuit isn't as small, as using NE555 timer chip will need couple of resistors and caps to get the job done. Still, simple and small enough. This one is for you guys wanting to get your PNP germanium fuzzes daisy chainable. (and i copied part of the text from the doubler post :))



25 comments:

  1. argggghh! wish I saw this before I ordered those max chips!

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    1. I drew this today and posted it couple of hours ago :) But don't worry. You can always stock up on both :)
      +m

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    2. Hi Mirosol,

      Is this one verified? Can I use the NE555N instead of the NE555?


      Grtz

      R

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    3. I'm not aware if someone built this... So no.

      That's the same chip, so it's ok.
      +m

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  2. Yeah, I ordered 7660S today :P

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  3. Thanks miro! This is a HUGE help. Nothin' like savin' money!

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  4. Oh yes, a quick calculation of components + verobrd less than 0,50$.. Nice :)

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  5. is it possible to use it as a bipolar supply?
    I mean using the second row as a +9 output.

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    Replies
    1. Yes. That's the way many would want to use inverters.. Just take +9V to circuit from row 2.
      +m

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    2. I'll try it as soon as I can...
      thanks for the help as usual!

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    3. finally I've found some spare time to make this,
      It's working like a charm!
      thank you so much for this, now i'm curious to implement it in a anderton eq, I've noticed that the oscillator was set to a really high frequency, so I keep big hopes about the absence of noise :D
      tested with a 5.20v supply, output is +5.20 -4.90. great!

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    4. after a while the voltage stabilized to circa 1.5v less than the +ve output... I suggest to use a higher voltage (max 16v I think) and a regulator after this circuit

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  6. Made this and boxed it with a Sunface Ge and works great - voltage was a little low 7.5-8v but that's fine with the Sunface.

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    Replies
    1. What was you input voltage?

      I've been waiting to get this one tagged..
      +m

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  7. I too built this with the Sunface GE and am putting in 9.56 volts and it sends out -7.06 volts to the fuzz. I just tested this because you asked otherwise it sounds good.

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    Replies
    1. Could be a feature. Most fuzzes should be fine with -7 to -8 volts, but this probably won't be perfect solution for other applications.
      +m

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  8. Do you know what frequency this is set to run at?

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    1. Around 20kHz.
      http://www.circuitsonline.net/schakelingen/139/voedingen/negatieve-spanning-met-ne555.html
      +m

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  9. About the offboard wiring, must we assume just to invert the led position?

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    Replies
    1. +1 on this question... But refering to the input/output jacks grounding. Should I use a specific side of the ground ... or ground is "ground" no matter what?

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  10. Hi guys! Does anybody know if I could use this component instead of the ne555? Thank you in advance!
    http://www.mammothelectronics.com/LMC555CN-CMOS-Timer-p/400-1080.htm

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  11. Hi Sebastian, i found this in the web:
    "Use a standard (bipolar) NE555 timer - not a CMOS type. CMOS timers do not have the switching abilities of the bipolar types, and output voltage will be lower."

    http://sound.westhost.com/project95.htm

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  12. Works fine on my positive ground Parapedal!

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  13. I built this but getting -3.9V - any ideas?
    Thanks!

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    Replies
    1. My quick guess is that you used 1N400X instead of Schottky diodes. Schottky diodes have a lower forward voltage drop which means that you will lose less voltage along the way.

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