Signal generator

In message , dated Sat, 5 Aug 2006, Dh writes

A 741 will do that. Even a 709 will. You do need a few other parts.

Well- since you demand "highly stable" instead of just "very stable," you probably need one of these:

For small values of "highly stable" I agree, but the OP needs to define highly stable. Is it frequency, amplitude or both that need to be highly stable?

In message , dated Sat, 5 Aug 2006, Fred Bloggs writes

The 9858 should do 400 Hz reasonably well.

what about a microcontroller directly ? youl need one to program the DDS anyway.

Colin =^.^=

There used to be an IC called XR2206 (i think) which was a very nice signal generator indeed .... look it up on gewgle ...

He's asking for a highly stable oscillator, and the Exar XR2206 uses a RC network to define the period of a triangular wave, which is then rounded off to produce a mediocre approximation to a sine wave.

For sufficiently unambitious values of "highly accurate" it might do. A DDS chip is probably the easiest solution, though at 400Hz a minimal PIC programmed to produce one of Don Lancasters "magic sinewave" binary sequences might be adequate. In either case the OP would need to add an anti-aliasing filter, but the design wouldn't be too demanding - the DDS chip needs less filtering than a magic sine-wave, but neither would need much.

I still think the 2206 is a very decent solution to his problem ....why dont we let him decide ?

In message , dated Sat, 5 Aug 2006, snipped-for-privacy@ieee.org writes

..and you assume he means it. We have yet to receive even a barely adequate specification, hence my suggestion of a 741.

"John Woodgate" schreef in bericht news: snipped-for-privacy@jmwa.demon.co.uk...

Yep, if 50Hz or 60Hz is close enough I have an idea too.

I'm guessing that the OP is after an AC voltage reference. I.e., 400 Hz @ 10 Vrms. I suggest that he look to Thaler for their SWR200 Sine Wave Reference. Just add two capacitors to set the frequency, +/- 15V for power and he's all set.

Cheers!!!!

-- Many thanks,

Don Lancaster voice phone: (928)428-4073 Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 rss:

Please visit my GURU's LAIR web site at

Where's the fun in that?

In article , John Fields wrote: [....]

MAINS --[DIV (5 or 6)]--[PD]--[FILTER]--[SINE VCO]--+--->400Hz ! ! -------[DIV 40]

• lightbulb for amplitude control

In message , dated Sun, 6 Aug 2006, Ken Smith writes

You could get a friend to help and make some in your garage.

An eight pin PIC (or any other micro). You would have to do some programming, and some filtering and some amplification.

For best results he'd want to know some people called Hewlett or Packard.