> > I hope you are saying that the derating for the components was based on a > 15V max input. If there are 15V rated parts on the input rail, that's > not good.
I just took a glance at the K3S schematics to see if I could tell. Result was inconclusive. Notes: C3 (10 uF), C8 (10 uF) and C22 (470 uF) on the PA I/O board have no voltage ratings specified on the drawings. C85 (10 uF) on the DSP power supply has no voltage rating on the drawing. C52 is 1000 uF / 10V on a regulated 8V rail. That wouldn't have gotten past the design reviews I have been subjected to. Most of the other caps on the 8V rail(s) are rated for 25V. All but the 10 uF parts are likely tants or electrolytics. 10 uF could be those or ceramic. C102 (10u, 10V) is ceramic and may be unsufficiently derated. (See the recent thread on the loss of LCD segments; known problem to Elecraft support.) Very few of the low value caps (which are all are probably MLCCs) have a voltage specified on the drawings. I probably missed something as It is hard to do schematic review with PDFs, but we're lucky to have those. Thank you, Elecraft! -ch On Mon, Sep 4, 2017 at 5:12 PM, Christopher Hoover <c...@murgatroid.com> wrote: > I can answer that one. It is in the equipment manuals. 15V max. >> Some components are rated at that level. > > > I hope you are saying that the derating for the components was based on a > 15V max input. If there are 15V rated parts on the input rail, that's > not good. > > 73 de AI6KG > > > > > On Mon, Sep 4, 2017 at 4:49 PM, Jack Brindle <jackbrin...@me.com> wrote: > >> I can answer that one. It is in the equipment manuals. 15V max. >> Some components are rated at that level. >> >> You really don’t want to go too high or you lose a lot of power >> dissipated in linear voltage regulators inside the equipment. >> Of course too low and the transmitters can have issues. Things like the >> KRC2, W2 and other peripherals should be able to >> work pretty well las low as 8 or 9 volts, but they are most happy at the >> same level as the transceivers. >> >> - Jack, W6FB >> >> >> >> > On Sep 4, 2017, at 4:31 PM, Phil Kane <k2...@kanafi.org> wrote: >> > >> > On 9/4/2017 3:29 PM, Jim Brown wrote: >> > >> >> For several decades, 120/240 VAC became the Standard for single-phase >> >> distribution in North America. Those of us who call call it "110" are >> >> showing our age. :) >> > >> > And how many sources refer to it as "115 V" or worse "117 V". >> > >> > That raises the (on topic) question of what is the acceptable >> > excursion/tolerance standard for equipment designed to run on "12 V DC" >> > in light of the LiFePO4 battery discussion here recently. >> > >> > 73 de K2ASP - Phil Kane >> > Elecraft K2/100 s/n 5402 >> > >> > From a Clearing in the Silicon Forest >> > Beaverton (Washington County) Oregon >> > ______________________________________________________________ >> > Elecraft mailing list >> > Home: http://mailman.qth.net/mailman/listinfo/elecraft >> > Help: http://mailman.qth.net/mmfaq.htm >> > Post: mailto:Elecraft@mailman.qth.net >> > >> > This list hosted by: http://www.qsl.net >> > Please help support this email list: http://www.qsl.net/donate.html >> > Message delivered to jackbrin...@me.com >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to c...@murgatroid.com >> > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
