At first thanks to all who gave me tips and informations until now.

I will specify the function of the IC I try to identify a bit
further:

The whole assembly seems (as far I had the possibility to measure)
only to produce a clipped, rather distorted 40 kHz signal which is
frequency modulated with an audio signal (whatever you like, music,
etc.) fed in through a connector. The modulated 40 kHz output goes to
a pair of ultrasonic piezo transducers. Currently I have only a
handmade scetch, but I could provide a CAD schematic. I will
not post in on my homepage, but I could e-mail it on request.

Besides, I checked all ICs with 7501 or 8025 (the numbers on the
chip I mentioned yesterday) as part of their name, and none fits. I
tried Internet search engines, www.questlink.com, www.chipdir.com,
searched in my old IC Master etc.

Thanx, regards
Matthias Mansfeld
-----------------------------------------------
Matthias Mansfeld Elektronik
* Printed Circuit Board Design and Assembly
Am Langhoelzl 11, D-85540 Haar, GERMANY
Phone: +49-89-4620 0937, Fax: +49-89-4620 0938
E-Mail: [log in to unmask]
Internet: http://www.mansfeld-elektronik.de

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