antonxj
NAXJA Forum User
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- South Africa
rpyne said:As I look closer at this design, I have a minor concern with the 74F04 and 74F14 without any voltage regulation for Vcc. It has been a number of years since I have done any hardware design and I don't have any data books handy, but I seem to recall that their Vcc NOM was +5V. I am not saying that they won't work with a high Vcc, but I have a concern about their life.
ahhh good spotting

the 74xx series needs V+ between 2 - 5.5 Vcc, so useing a 4069 instead of the 7404 will solve that, but what about the 7414? I lwill look at a 5V supply for these then you could use either. It was in the plan in my head, and only halfway on the PCB:looney:
the 40xx series cmos can handle V+ of 3 - 18 Vcc but i'll look at using a LM7812 for all the rest, including a 1000uF Cap on the input side, also left some of the unused gates "open" will set them either high or low.
so the PCB is not off to production yet.
thanks for the heads up tho, but what you can't see is that Fletch and i are addressing these very errors in PM, but anyone that spots a prob. let me know, it's the reason i post the PCB here before it goes to production

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