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Old 27th Apr 2019, 8:29 pm   #87
DonaldStott's Avatar
Join Date: Aug 2015
Location: Glasgow, UK.
Posts: 758
Default Re: Turntable Stroboscope

Originally Posted by TonyDuell View Post
What do you get on pin 3 (or pin 5) of the 4081?

Do you have a 'scope? If so, what do the signals on pins 3 and 4 look like?
The readings on Pins 3 and 5 are widely fluctuating as well - makes no sense to me!

A complete mess on my ageing Farnell 30-4D oscilloscope - this needs a lot of urgent TLC so I don't trust what I'm seeing (not sharing it here!!!)

Originally Posted by David G4EBT View Post

Re the 'BE' suffix:

A plain CD4081 is 'unbuffered'.

'B' simply means the IC has a buffered output. The pinouts are identical.
'E' means 'plastic encapsulated dual in-line package'.
Thanks David, although your link scared me - I'll need to find some time to read and digest.

Meantime ...

I think I'll need to PAUSE this Thread - I've taken up enough of your valuable time although it has been a very worthwhile educational journey, for me.

Made some great progress and actually managed to get something oscillating at a steady 300Hz - fell at the least hurdle though trying to generate an asymmetric square wave. So close ...

A huge thanks to everyone who contributed their knowledge, expertise, patience and perseverance, it really is appreciated.
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