At 10:02 PM 5/25/2006, John Waters wrote: >Hi All, > >I encountered some strange problems when was doing experiments on a simple >oscillator circuit. I built a circuit that was made up by the 4 COMS NOR >gates in a CD4001. I used the first 2 NOR gates to build a simple monostable >that turned on or off a low frequency oscillator made up by the 3rd and 4th >NOR gates. The circuit was built on a breadboard, running on 6V batteries. I >found the following strange things happened and could not explain why:- Did you ever resolve this? If not, I'd be looking at the input pins of the chip. Your symptoms accurately describe what can happen with floating CMOS inputs. Are all the un-used inputs tied high or low as needed? Make sure that you have a small (100n) bypass cap between Vss & Vdd near the chip. I've seen a few responses that suggest not using a plastic breadboard for this kind of stuff. Nonsense! Plastic breadboard sockets work VERY well for this kind of thing. If you are using large value resistors for any of your inputs, I'd suggest putting a metal sheet under the breadboard strip and connecting that sheet to the Vss rail on the breadboard strip. This will help keep much of the external noise from influencing the circuit. dwayne PS - I routinely debug low level audio designs using not much more than breadboard sockets sitting on top of a ground plane. No real problems. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 22 years of Engineering Innovation (1984 - 2006) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist