DDS (Direct Digital Synthesis) for Metal Detector

[Lake]

Just a design idea.. This circuit might be usefull for metal detector frequency generator. Multiple frequencies of sine waves can be generated easily for one measurement and sine quality is quote good..
Other pic with LCD would handle the frequency setup with and measure response..

http://hem.passagen.se/communication/dds.html

Are there any commercial metal detectors which use DDS?

Here is another way to synthesize sine wave with just eeprom..
uC could handle the timing for it..

http://web.telia.com/~u85920178/eprom/epromosc.htm

[Carl-NC]

I brought up DDS some years ago, but at the time they were a little high on power. Analog Devices now has some low-power DDS chips (I used to work in that design center) that would be good choices. DDS is especially useful if you want to do phase-linear frequency hopping, which is one concept I'd like to try. I don't know of a detector that uses DDS.

- Carl

[TheWizard]

Also look post "Is DSP useful?" https://www.geotech1.com/thuntings/s...ad.php?t=13503

Regards

[ivconic]

Dont know about your case, but in my case it is impossible to find AD98.. ic's at local shops. Four years ago i looked up for AD9850 or AD9851 without success. Same situation now. Nearest supplier is in Germany! Besides, those ic's are to expensive to be ordered in set (10pcs,20pcs,100pcs).
So i gave up of few very interesting designs! Only cose couldnt find those AD's!
Two years ago i even visited Malta and lived there for one year. Local supplier there was Maplin at the time. I went and ask a man and he told me same story; must be ordered from England (central supplier) by very hot prices also! So....what to say more...? I gave up and left it to wait better times...heh!

[Lake]

I ordered mine as a free samples from analog website. They arrived in two weeks with TNT... They just called after to ask what my company was doing etc, but received the chips.