Hex and BCD puzzle (to me anyway)

Thread Starter

cornishlad

Joined Jul 31, 2013
222
I'm looking to buy an (old) UNILAB counter module of amazon (unilab counter module 120) with a view to using it in a project - and saving me a little construction. But I can see from the picture in the ad that there is a CD4510BE BCD up/down counter, feeding a MC14495 which is a hex decoder driver. Both description obtained from Googling data sheets.
My question is why is the dec/driver not a BCD type and how can the 4510 and 14495 work together..or am I missing something ?
 

AlbertHall

Joined Jun 4, 2014
11,961
The '14495 takes four binary digits, interprets them as hexadecimal, and drives a single seven segment display.
If you feed those four inputs with the four bits of a BCD digit then the display will correctly follow the BCD digit.
 

Thread Starter

cornishlad

Joined Jul 31, 2013
222
Thanks..I made incorrect assumptions about what hex actually was. I'm pretty sketchy about logic ! Does that mean if I swapped out the 4510 for a 4516 I could count to F ?
 

dl324

Joined Mar 30, 2015
14,329
I'm pretty sketchy about logic !
It's a different numbering system (decimal vs. hexadecimal), not logic. Digital logic is based on 1's and 0's. We can think of groupings of 1's and 0's as binary, octal, decimal, or hexadecimal. We call a single 1/0 a bit, 4 bits is a nibble, 8 bits is a byte, etc.
Does that mean if I swapped out the 4510 for a 4516 I could count to F ?
Yes.

EDIT: corrected 0's, some were o's.
 
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Thread Starter

cornishlad

Joined Jul 31, 2013
222
Thank you for all the helpful replies..The unit is only a fiver.. It does only have a single 7 segment display but will serve my project quite well with minimum mods. I have now googled the Hex sequence and am a little wiser..I'll go ahead and order one..
 

Thread Starter

cornishlad

Joined Jul 31, 2013
222
As a follow up to the previous I actually need something to divide by 30 for my on/off long term attempts to make and monitor a pendulum clock with electronic control..After ordering the board my question related to, this morning, I came across something even more suitable that requires the absolute minimum of mods and so increditable cheap..From China, via eBay of course. I have previously been chuuffed to find very cheap devices for this project (H bridges, Opto interupters for starters) on e\bay but this takes the biscuit !!
eBay search "2-Digit 30-60S Counter Timer" About £3..Always worth a thorough search !..
 
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