Thanks Attila Burts looking to separate the rcvr/remodulator. I am fine. Yes indeed I did look up the hc specs. I thought it was a 5v logic actually. I knew it was not at all like the 74c series. Regards Paul
On Tue, Jun 18, 2013 at 5:21 PM, Attila Kinali <[email protected]> wrote: > On Tue, 18 Jun 2013 10:52:24 -0400 > paul swed <[email protected]> wrote: > > > Interesting the HC will work all the way down to 2.2V so everything can > be > > run from 3 Volts. > > I don't have a spec sheet at hand, but are HC types speced down to 2.2V? > I thought it was something around 3V > > > No idea as to the effect of the xtal oscillator maybe the 3.9 M R needs > to > > be changed. > > Probably not. the 3.9M resistor is to give the oscillator circuit > (which is an unbuffered inverter) a DC bias. Its value is usually not > critical. > > > It also appears that the HC chip may doing the lions share of current > > consumption. Spec sheet says up to 20 Ma. Hard to believe actually. > > As long as it's mA not MA, it is indeed believable ;-) > HC used quite a bit of current. Especially when toggling at high speed > (where as high speed is to be seen relative to the 70s when these chips > were designed). > > > As for driving lengths of wire over distance it needs to be a buffer > chip. > > 74hc244. But that seems like serious overkill it can drive 20 ma per > port. > > If it's just a single signal, why not use a pair of digital mosfets like > FDV302P/FDV303N? These can drive a big load (680mA speced, with good > cooling) > and are can be interfaced with 3V logic. > > > > Attila Kinali > -- > The people on 4chan are like brilliant psychologists > who also happen to be insane and gross. > -- unknown > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
