Simple, cheap, square/triangle/sine-wave generator 2012-05-25

alec_t submitted a new article:

Simple, cheap, Square/Triangle/Sine-wave generator - A test signal generator is invaluable when making or repairing electronic equipment. Although a ful

A test signal generator is invaluable when making or repairing electronic equipment. Although a fully-fledged, accurate (and expensive!) sig gen is desirable, there are many occasions when a simple, non-calibrated, highly portable signal source will suffice for a quick test such as signal tracing. To that end I've designed this circuit which selectively generates square, triangle and pseudo-sine waves in three frequency ranges covering 15Hz to 2MHz.
The core of the generator is a...

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alec_t , thank you for this circuit!. It will come in handy for a project I'm working on now. A question for you, will a single supply (rail to rail) op-amp work in this circuit? If so could you suggest one to use?

Again thank you.

Almost any op-amp (single or dual supply) with a reasonable gain-bandwidth product should be ok, and supply voltage isn't critical provided the V+ to V- voltage difference is less than 15V (the max CD4093 operating voltage). Rail-to-rail operation is not really necessary because the op-amp inputs are biased around mid-rail voltage and the output voltage swing is only a volt or two. The circuit shown uses an LT1007, but LM324 etc should be fine (though I haven't checked its high frequency response. Good luck with the project.

Thank you for your answer. This will be my first time using an opamp so thats why the question.

Simple but effective!