Hi Please explain how a common mode choke on the +12 and ground does nothing to help keep the supply clean.
Bob On Feb 26, 2010, at 9:57 PM, WarrenS wrote: > > >> Lots of questions .... > Same Simple answer. > Make the +12 volts is as good as you can get it, For the rest any general > purpose PS works fine. > And a Common mode choke filter does not get ride of line noise on the +12 V > or Line voltage sensitivities, both are important on the +12V > > ws > > **************** > Hi > > Depending on the supply setup, a common mode choke might also be a good idea. > > The +12 runs the OCXO, so it's going to have an impact. > > What about the +5 Volts? Obviously it needs to be crud free. Gross changes > will impact the temperature of the unit. What about small changes? Is it > running the maser reference for the DAC or does that come off the +12? Is +5 > just a digital supply? > > Lots of questions .... > > Bob > > On Feb 26, 2010, at 6:59 PM, WarrenS wrote: > >> >> >> Yes, I Did that, The +5 and -12 has NO effect on freq or operation of the >> unit except for really far out voltages. >> I tested mine with the -12 from -2 to -15 and could see no effect in the >> e-11 range. >> The -12 is used for the RS232 and the -Dac out so If you don't need the neg >> Dac out voltage or neg RS232 Drive, then it can pretty much be anything. >> But It should be kept in -7 to -13 range, and common sense means there >> should be little noise on it so it does not couple into other things. BUT >> the circuit it's self does not care what the supply is at or what is used. >> >> The +12 on the other hand, Needs to be stable and quiet with no ripple. >> I found using a +15 volt supply feeding a 12V three terminal will heat >> slinked regulator a good way to go to keep ALL the ripple out of the +12V >> >> ws >> >> ******************* >> >> Hi >> >> Has anybody actually measured the supply sensitivity on the -12 volt line to >> see weather a 5 volt change makes any noticeable difference in the output >> frequency? The power on -12 is very low, so there should be negligible >> thermal impact from a change. >> >> Bob > > > _______________________________________________ > 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.
