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Function Generator

When i was using operational amplifiers at school lab i wanted a function generator at home to play with and work on circuits with Op Amps for better understanding. So i found on the internet a free function generator circuit which uses the IC XR-2206, i printed the PCB with my UV epxosure box, i bought an enclosure box, i put everyhting inside and here is the result.

The function generator can generate Square, TTL, Sine and Traingle waveforms from 1Hz to ~1Mhz with Voltage regulation to Square Sine and Traingle waveforms.

The front panel is a printed cardboard.

Function Generator

Function Generator

Function Generator

Inside Function Generator

Inside Function Generator


Here are some construction photos, taken with my mobile phone before buying a digital camera.


Drilling the holes

Drilling the holes

Soldered pcb


Homemade PCB

The schematic from the internet

The Scheme

The PCB from the internet



  • john
    21/05/2012 - 01:32 | Permalink

    Hello ,very nice project and nice site!!
    Could you tell me please how you write the letters on the case? for exaple TTL, SQUARE, VOLTAGE, FREQUENCY e.t.c

    • 21/05/2012 - 08:47 | Permalink

      Hello, thank you for your good words and your interest. The letters are printed on a cardboard using a common printer. A transparent sticker has been also sticked at the front side for better appearence 

  • John
    06/07/2012 - 13:28 | Permalink

    Hello. Thank you for this design it is nice.
    If some one needs a sweep generator using XR2206 or other circuit ideas,  I have found many interesting circuits on

  • Joachim
    14/08/2012 - 03:58 | Permalink

    Hello, nice project, I'm trying to do this myself and I've got a few questions.
    What's the value for the capacitor labeled as 100? And for the one labeled 2.2? And the one labeled 1000? (C3, C7), (C4), (C0).
    And how did you connect the 74LS00?
    Hopefully you can help me out, thanks!

    • 14/08/2012 - 12:16 | Permalink

      I don't have the circuit in front of me at this time so, 100 as i can see from the schematic and the silkscreen is a radial electrolitic with polarity capacitor. A common value for these capacitors is uF. So 100 means 100uF. The same is for 2.2uF and 1000uF. 

      Because it has passed a few years since i assembled it i don't remeber why i have used 74LS00. The only think that i'm sure for is that the PCB i had print was from the film i posted above. I have just replaced the 7413 with 74LS00 and nothing more. The circuit connections are the same as above.




  • Peter
    26/11/2012 - 01:17 | Permalink

    Someone send me schematic in Eagle?

  • Ishmael
    30/11/2012 - 22:25 | Permalink

    Great project!  Do you have a Bill of Materials?  Where did you find the XR2206 chip?  Also, where did you get the nice knobs?

    • 30/11/2012 - 22:28 | Permalink

      Hello my friend. No there isn’t a bill of materials but you can find them from schematic. I found the XR2206 and the knobs from a neighbor store

  • 19/02/2013 - 22:27 | Permalink

    Good Work.

    could you please upload the original pcb layout.??

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