Hi Each project is a different “experience”. Some things are way more susceptible to switching noise than others. Some switchers put out way more noise than others. You would not run a linear supply on a computer. The low noise front end of a radio is going to need a quiet supply …..
There are a lot of linear supplies that come in dissipating more heat than they deliver to the load. You can also do fancy designs that are up above 90% efficient. (count on using BGA’s for that one ….). First and easiest question: Does this beast *really* need to be powered up all the time? Second question: really ???? :) There aren’t a lot of devices that need to be / should be run 100% of the time …. My biggest answer - turn it off. Bob > On Dec 22, 2019, at 2:37 PM, Taka Kamiya via time-nuts > <time-nuts@lists.febo.com> wrote: > > Most commercially manufactured time and frequency sources use switching power > supply. However, when contacted, tech support for SRS says, in regards to > PRS-10, use linear power supply. I am guessing, when manufacturers design > complete units, they take switching noise into consideration and deal with it > with filtering, etc. > I've seen data on TVB's site and others that demonstrates effects of power > supply noise. > Now, when I make DIY timing sources, I started including linear power > supplies. My PRS-10/GPS unit has 2.4A 24V linear supply for PRS10 and > switching supply for stuff that really doesn't care. It seem to work well. > But the problem is HEAT! Almost all timing devices are heat sensitive and > drift accordingly. Open frame linear supplies has efficiency of somewhere > around 65 to 70%. I could, for example, partition inside the case and fan > cool the P/S only but doing so for every single DIY unit becomes tedious. > First question to the group is, how do YOU manage this problem? > My thought now is, what about making an external linear supply ONLY and > supply all the voltages connected units could possibly need. I could fan > cool that! I happen to have a rack mounted UPS unit that is well beyond > service life. I can gut it and stuff open frame supplies to 24V, +/-12V, and > 5V. Does anyone see issue with this? Of course, on timing device side, I > will have to put large enough cap to decouple. > PS. I was bit by a telecom surplus time source bug. I have various one > already running and more on the way. > > --------------------------------------- > (Mr.) Taka Kamiya > KB4EMF / ex JF2DKG > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
