View Single Post
Old 27th Apr 2019, 6:46 pm   #86
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,761
Default Re: Turntable Stroboscope

Quote:
Originally Posted by DonaldStott View Post
O.k. all wired up and double/triple checked my connections.

Something not quite right as I'm getting 8.5 - 8.6kHz on the Output from Pin 4 (2Y) of the CD4081 (actually a CD4081BE but I'm assuming the Pins are the same?)
Re the 'BE' suffix:

A plain CD4081 is 'unbuffered'.

'B' simply means the IC has a buffered output. The pinouts are identical.

A 'buffered' CMOS device is one for which the output ON impedance is independent of any and all valid input logic conditions, both preceding and present. (I'm told!).

'E' means 'plastic encapsulated dual in-line package'.

An fuller explanation of buffered and unbuffered CMOS can be found here:

http://www.ti.com/lit/an/scha004/scha004.pdf

Hope that helps, albeit it doesn't answer they key questions.
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline