* My supply is 12v DC. Can I simply use a 5V power FET to drop the voltage to 5V, and still get it to work? Are there any pitfalls in using a power FET?
It'd be better if you use a regulator: 7805 should do, or an LM345, which is easier to fine-tune.
* What are the precautions to be taken of one set of leads from the 4017 turn out to be approximately 3-4 feet long? Would dropping the voltage to 5V have an adverse effect?
I'm not completly sure how to convert to metric, but as long as you keep the frequency low enough, the length of the wires shouldn't be a Real problem... even wire resistance should at these lengths be neglible... But personally, I'd consider a transistor after the lead. Then have the transistor light the led...
* Would it be best to have a 4017 mounted on each display unit and let the driver unit carry only the 555?
IMO it would be less expensive to have only 1 4017, and send the output to the seperate boards, buffered by transistors. |
