XR2206 Function Generator Kit Improved Instructions

Introduction

The XR2206 Function Generator Kit is available through various outlets at a selection of prices up to £13. I got one branded “ARCELI” via Amazon for £7.99.

Having got one, I would advise getting the cheapest one you can. Just take into consideration the trustworthiness of the seller to be sure you get what you’ve ordered, paid reasonable post and packing charges for, and that you will actually receive it.

Having looked at pictures of the finished article I suspect all brand’s circuits are the same but each brand may source their components differently.

Now you can see my other post “A Function Generator Built From A Kit Using An XR2206” to see how I got on with building these kits.

Quality of The Kit Parts

The Electronic Components And Circuit Board

I found the quality of all the parts to be good. All components were like all those used in modern electronic equipment. All the resistors had the same power handling capacity of a ¼W. This was reasonable for a low power device such as this XR2206 Function Generator Kit.

Similarly the electrolytic capacitor voltage ratings of 25v was ample.

The preparation of the circuit board was excellent too. Feed-through holes, tinning and lacquering, all looked good to me. Tinning solder had flowed well around the holes.

The Transparent Acrylic Case

All components are attached to the circuit board and the whole is expected to be housed in a Transparent Acrylic Case. This case has six faces all cut out from transparent acrylic sheet 2.5mm thick. The six faces consist of four sides a top (Front Panel) and a Base. The Front Panel is engraved with labels for the controls.

The case is held together around the circuit board by tabs on the edges of the four sides which fit into slots on the Front Panel and base. The case parts are nicely presented and look as if they were cut out and engraved with a LASER.

The Controls

There are three rotary control knobs (as viewed with the Power Jack on the left):

  1. The Output Level control is on the left. Weirdly it has to be turned ANT-CLOCKWISE to increase the level.
  2. The Course Frequency control is in the centre.
  3. The Fine Frequency control is on the right.

There are two sets of links for controlling Frequency Bands and Waveforms:

  1. The Frequency Band control is in the form of a five position link:
    1. 1Hz-10Hz,
    2. 10Hz-100Hz,
    3. 100Hz-3kHz,
    4. 3kHz – 65kHz,
    5. 65kHz-1MHz.
  2. There is another link control with two positions:
    1. sine wave,
    2. triangular wave. This affects the output waveform of the Sine Wave output connection.

The Connections

There are three screw terminals on the right (P1) used for output connections. They are the type which press down on the wire, not the ones where the screw bites into the connection wire and damages it. Top to bottom they are:

  • Ground,
  • Square Wave,
  • Sine or Triangular Wave according to the position of the two position link.

The power is provided from a 9v-12v D.C. supply of the users choosing, via a 5.5mm⨯2.1mm Power Jack (JK1).

Quality of The Instructions

This is the area that is lacking. The instructions are obviously translated from another language into English. They immediately stand out due to the regular reference to “welding” instead of “soldering”. My main reason for writing about this kit is to make the instructions clearer. Here are the original instructions on two sides of an A5 sheet:

XR2206 Function Generator Kit Instructions Page 1
XR2206 Function Generator Kit Instructions Page 1
XR2206 Function Generator Kit Instructions Page 2
XR2206 Function Generator Kit Instructions Page 2

How To Download An XR2206 Data Sheet

The data sheet for the XR2206 is available in HTML or PDF format from ALLDATASHEET.COM. Choose your format from the links in the list below:

The XR2206 Function Generator Kit Improved Instructions

1. XR2206 Function Generator Component Layout Diagram

The original component layout diagram is satisfactory and is almost identical to the image printed on top of the circuit board. So I have photographed the circuit board to display here instead.

XR2206 Function Generator circuit board showing how the components are laid out
A picture of the front of the XR2206 Function Generator circuit board showing how the components are laid out.

2. The Function Generator Component Table

Below I have produced my own table listing the components with their description and value. For non electrolytic capacitors I have also listed the code printed on them.

COMPONENTDESCRIPTIONCODEVALUENOTES
R1Wire ended resistorBrown, Black, Black, Brown1kΩUnpolarised
R2 (VR1)PotentiometerB50350kΩUnpolarised
R3Wire ended resistorGreen, Brown, Black, Brown5.1kΩUnpolarised
R4Wire ended resistorOrange, Orange, Black, Black330ΩUnpolarised
R5Wire ended resistorGreen, Brown, Black, Brown5.1kΩUnpolarised
R6Wire ended resistorGreen, Brown, Black, Brown5.1kΩUnpolarised
R7 (VR2)PotentiometerB50350kΩUnpolarised
R8 (VR3)PotentiometerB104100kΩUnpolarised
C1Electrolytic capacitorNO CODE100μFPolarised
Long wire is +ve
C2Ceramic capacitor1040.1μFUnpolarised
C3Electrolytic capacitorNO CODE10μFPolarised
Long wire is +ve
C4Electrolytic capacitorNO CODE10μFPolarised
Long wire is +ve
C5Ceramic capacitor1051μFUnpolarised
C6Ceramic capacitor47347000pFUnpolarised
C7Ceramic capacitor2222200pFUnpolarised
C8Ceramic capacitor101100pFUnpolarised
U1Integrated CircuitXR2206CPNotch is between P1 & P16
JK1Power SocketNO CODE5.5mm Outside × 2.1mm Inside
J1-J2Header Pins & CapXM2.542×2pinFor Changing Waveform
J3-J7Header Pins & CapXM2.545×2pinFor Changing Frequency Range
P1Output Connectors3×1term.Screw Terminal

3. Soldering Instructions

The soldered side of the XR2206 Function Generator Circuit Board after soldering.
The soldered side of the XR2206 Function Generator Circuit Board after soldering.
  1. The components are fed from the front of the circuit board (the side with the writing on.) Start with the smaller less sensitive components listed here. After pushing them through their holes splay out their wires to hold them in place while the board is turned over and soldered:
    1. Resistors (bend their wires at right angles near to their bodies),
    2. Ceramic Capacitors,
    3. Electrolytic Capacitors.
  2. Solder:
    1. The IC Socket (align the notch in one end with the picture on the circuit board,
    2. Blue Terminal Block (ensure the connection holes face the edge of the board,
    3. Power Socket,
    4. Potentiometers.
  3. After soldering, at any stage, cut the unnecessary wires off as close to the board as possible. Any bits that protrude will make the total height of the board and components so big that the lid (front panel) won’t fit. I discovered this the hard way. The tabs on the potentiometers and the power socket must be bent to lie flat. I have acquired small wire cutters which sit very flat against the board and have a spring to open them especially for this work. You can see them below:
Newsome Small Springy Wire Cutters (11cm long).
Newsome Small Springy Wire Cutters (11cm long).

4. Debugging Stage

  1. After completion of soldering insert the IC (XR2206) into its socket. Observe its polarity by looking for the notch in one end and align that with the notch in its socket. Also try and take anti-static precautions while doing this. The pins 1 to 8 may need to be straightened and pushed towards pins 9 to 16 to reduce the distance between them. There are plastic tools available to assist with this.
  2. Connect a 9v to 12v power supply (or battery) to the power socket JK1. JK1 is a standard low voltage power jack with an outer sleeve 5.5mm dia. and a centre pin dia. of 2.1mm NOTE: The centre pin is the +ve connection and the outer barrel is the -ve connection.

5. Using The XR2206 Function Generator

  1. With the Jumper Cap (link) in the J1 position the XR2206 Function Generator will produce a Sinewave output at the blue terminal of P1 labelled SIN/TRI.
  2. With the Jumper Cap (link) removed from J1 position the XR2206 Function Generator will produce a Triangular wave output at the blue terminal labelled SIN/TRI. When choosing this setting the Jumper Cap (link) can be placed in the J2 position to retain it so it doesn’t get lost. The pins at the J2 position are not connected to any part of the circuit.
  3. A Square Wave output is always available at the blue terminal labelled SQU. The mark to space ratio is not adjustable using this kit as provided.
  4. The AMP (Amplitude) control adjusts the amplitude of the Sine and Triangle wave outputs only. (“See Distorted Sine Wave” produced when the amplitude is set too high in the “Examples of The Waveforms Produced” below.) NOTE: This control is wired in reverse to what is normally expected, such that a clockwise movement DECREASES the amplitude and an ANTICLOCKWISE movement INCREASES the amplitude. When turned to maximum the sinewave output is very distorted. This can be checked with an oscilloscope.
  5. There is NO amplitude control for the square wave output. The amplitude is approximately 10.6V Peek to Peek from the one I’ve measured here (see the 4kHz square wave image below).
  6. The COURSE control adjusts the frequency generated by large increments.
  7. The FINE control adjusts the frequency generated by small increments.
  8. The Jumper Cap (link) J3 can be placed on the 2⨯5pin block in any of the five positions to change the frequency range covered by the COURSE and fine controls. The frequency ranges available are marked on the transparent cover and are:
    1. 1Hz – 10Hz,
    2. 10Hz – 100Hz,
    3. 100Hz – 3kHz,
    4. 3kHz – 65kHz,
    5. 65kHz – 1MHz.

Examples of The Waveforms Produced

The waveforms below have been reproduced with the aid of a PicoScope 2206B MSO. (The Y scale is in Volts.)

4kHz Sine Wave
4kHz Sine Wave
4kHz Distorted Sine Wave (Produced when the amplitude is set too high)
4kHz Distorted Sine Wave (Produced when the amplitude is set too high)
4kHz Triangular Wave
4kHz Triangular Wave
4kHz Square Wave
4kHz Square Wave

6. The XR2206 Function Generator Kit Schematic Diagram

My Version of The XR2206 Function Generator Kit Schematic Diagram
My Version of The XR2206 Function Generator Kit Schematic Diagram

NOTE: The two Jumper Caps (links) in my diagram are plugged onto the pins of header blocks J1-J2 or J3-J7. In each case the link is shown by a dotted line between two pins. Running along the middle of each header block is an arrow. The tail of the arrow is at the lowest Jumper Cap position and the point is at the highest Jumper Cap position. The original instructions only refer to J1, J2 & J3. My instructions continue this numbering to J7 to describe the five positions their J3 can be placed in.

If the kit was more sophisticated it would replace J1-J2 with a single pole two way switch and J3-J7 with a single pole five way switch.


END OF POST

Comments

15 responses to “XR2206 Function Generator Kit Improved Instructions”

  1. Nabman avatar
    Nabman

    Hi. Thanks for this article. I suppose this has one output. Would it be possible to split the output to feed stereo equipment input? What buffer resistors values would you recommend in this case? Thanks. Nabman

  2. Gary G Martin avatar
    Gary G Martin

    Thank you very much for this well written set of improved instructions. I plan to use this signal generator to produce 24 kHz sine waves, then to pre-amp, then to amp, then to tweeter. This sound frequency cannot be heard by most people but will be a frightening screech to the blankity blank deer that eat my garden plants.

    1. Helpful Colin avatar

      Hi Gary,
      Sounds like an interesting little project. Please write again and tell us how it went.
      Regards, Colin.

  3. ED MORGAN avatar
    ED MORGAN

    Thank-you so much for this improved documentation of the Chine-Lish datasheet that came with the kit. I wish this kits were available way back when I was at Purdue and when an 80286 was the hot CPU… 🙂 ..don’t calculate those decades!!!

  4. Jefry117 avatar
    Jefry117

    Hermano estuve buscando como oro el esquematico gracias por subirlo en buena calidad se aprecia bastante!!

    1. Helpful Colin avatar

      Hola Jefry117,
      Estoy feliz de que lo hayas encontrado útil.
      Atentamente, Colin.

  5. Van Montagu avatar
    Van Montagu

    Bonjour super article, je cherchais des informations pour me lancer dans la soudure de mon kit, je suis assez débutante, et je me posais une question par rapport aux condensateurs, est -ce que la masse est représenté par la zone hachurée sur le pcb? Merci

    1. Helpful Colin avatar

      Google’s translation into English: Hello great article, I was looking for information to start soldering my kit, I’m quite a beginner, and I was asking myself a question about capacitors, is the mass represented by the hatched area on the pcb? THANKS

  6. Van Montagu avatar
    Van Montagu

    Erratum je viens de mieux regarder le superbe première photo (oui elles sont bien faites), j’ai compris où était le négatif et le positif. Merci pour ce tuto 🙂

    1. Helpful Colin avatar

      Google’s translation into English: Erratum I just took a better look at the superb first photo (yes they are well done), I understood where the negative and the positive were. Thanks for this tutorial.

  7. Trevor Baker avatar
    Trevor Baker

    Hi Colin
    I too bought the Arceli version of the kit and must thank you for your improved instructions, especially as the ‘official instructions’ which came with my kit are barely readable!
    I had already thought of replacing the jumpers with switches and will probably do so.
    Regards
    Trevor

  8. ossdevel avatar
    ossdevel

    Thank you so much! Just got one with NO INSTRUCTION AT ALL! From UAE…. [8()… Your efforts to make it understandable are appreciated with all my brains 😉

  9. GIULIANO VIGARANI avatar
    GIULIANO VIGARANI

    Il generatore che comprato genera delle sinusoidi orribili Perche’
    Grazie

    1. Helpful Colin avatar

      Ciao Giuliano,
      Sono stato troppo occupato per rispondere fino ad ora.
      Ho modificato il mio articolo e aggiunto alcune forme d’onda prodotte dal mio XR2206.
      Sono d’accordo che le onde sono tutt’altro che perfette e sono piene di distorsioni e armoniche, ma questo è un dispositivo economico rispetto a un buon oscillatore.
      Se le tue forme d’onda sono buone come le mie, non posso darti alcun suggerimento su come migliorarle. Se non sono così buone potresti avere un guasto al tuo XR2206 e dovresti verificare problemi con le saldature e la posizione sulla scheda dei vari componenti. Oppure il circuito integrato potrebbe essere difettoso.
      Per favore, scrivimi di nuovo se trovi un difetto.
      Buona fortuna.
      Saluti, Colin.

      Hi Giuliano,
      I’ve been too busy to reply until now.
      I’ve edited my article and added some waveforms produced by my XR2206.
      I agree that the waves are far from perfect and are full of distortion and harmonics, but this is a cheap device compared to a good oscillator.
      If your waveforms are as good as mine then I can’t make any suggestions as to how you can improve them. If they are not as good you may have a fault with you XR2206 and you should check problems with the soldering and location on the board of the various components. Or the integrated circuit could be faulty.
      Please write to me again if you find a fault.
      Good luck.
      Regards, Colin.

  10. Charles Brombaugh avatar
    Charles Brombaugh

    Hello Colin,
    Your instructions are far better than those in my kit. The line drawing showing the parts placement and the schematic are great information that were not included with my kit.

    With a few suggestions, my 17 year old grandson built the kit in 2 hours and it worked immediately when connected to power. The only problem is that it cannot generate many frequencies in the 1 Hz to 1 MHz range. Using my Siglent oscilloscope, the range of frequencies for the 5 bands are: 0.6 – 1.8 Hz, 6.67 – 17.57 Hz, 150.7 – 335.9 Hz, 3.2 – 8.52 KHz, and 55.8 – 145.04 KHz.

    I have not seen this problem mentioned in any or the reviews of this little gem. Do you have a suggestion of how to resolve it?

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