04:43 <sb0> whitequark, vacuum is 1e-6 ...

04:59 <whitequark> ok, so the same then

04:59 <whitequark> it reached that in maybe ten minutes. equilibrium with the leak.

04:59 <whitequark> how hot is the pump? (measure on the *black* bottom surface, Al has very low emissivity)

05:06 <whitequark> sb0: hm, actually it might still conceivably be water

05:06 <whitequark> the pump docs mention baking it out for *four hours*

05:10 <whitequark> oDuring operation, if the temperature of any surface of the pump is higher than 45 C, the pump is

05:10 <whitequark> too hot and you must increase the cooling.

05:11 <whitequark> (or if there's any bakeout at the inlet flange)

05:43 <sb0> yes, bakeout is supposed to take a long time. and you should raise the temperature slowly ...

05:44 <sb0> 48C

05:44 <sb0> whitequark, should I shut it down and how?

11:43 <cr1901_modern> Hmmm... looks like Arty is sold out. Between the FPGA used (Artix 7 35t) and the amount of memory on board (256MB), I'm a little surprised it still costs less than miniSpartan6+. I guess Digilent just has more resources to drive costs down.

13:09 <whitequark> sb0: https://recode.net/2016/04/19/viber-end-to-end-encryption-security-update/

13:09 <whitequark> this is why whatsapp deploying e2e was an incredibly important event; it was a tipping point of sorts

14:10 <sb0> whitequark, any ideas for a cheap multichannel plate?

14:10 <sb0> Alek is looking for one

14:11 <whitequark> no, not really

14:11 <whitequark> I need one as well, in case you figure out how

14:13 <sb0> isn't what they use in image intensifier tubes?

14:13 <sb0> *isn't it

14:14 <whitequark> I only really know the use in mass spectrometer detectors

15:35 <whitequark> sb0: the IEC power strips have shipped

15:39 <sb0> btw I have a crappy chinese power supply that we can use for the ion gauge filament

15:39 <whitequark> the filament power supply is actually the simplest part of all

15:40 <sb0> yes, but it's the immediate blocker right now

15:40 <whitequark> there is a wide variety of prefab modules that are suitable for this

15:40 <whitequark> ah, sure

15:40 <sb0> the reason it's crappy is not cheap components but incompetent design

15:41 <sb0> it has lots of problems, oscillates, i even had the microcontroller crash once which resulted in full voltage at the output

15:41 <whitequark> yes

15:42 <whitequark> I opened these linear supplies, the design is very bad

15:42 <whitequark> mostly just really old and not particularly well done even when it was new

15:42 <whitequark> and the build qualty is bad too, I had a ground-to-positive short in mine

15:42 <sb0> it's a different one

15:42 <sb0> from dipai-power

15:42 <sb0> it seems they tried to make it nice, but could not

15:43 <whitequark> that's actually one reason why I went with switching ones

15:43 <whitequark> you have to actually apply your brain to make it work decently

15:43 <whitequark> but also QJE is quite good at electrical design and assembly too, I can show you the insides of that supply

15:44 <whitequark> btw, I think the main reason it oscillates is that this linear design is fundamentally flawed for loads that aren't linear

15:45 <whitequark> (this = selecting one of a few preselected transformer taps and then dumping the rest into heat)

15:45 <whitequark> although... our load *is* linear.

15:45 <whitequark> maybe it's both.

15:45 <sb0> filament? not really

15:46 <whitequark> they're really awful for loads that exhibit even the tiniest negative resistance

15:46 <whitequark> e.g. my CFL plasma coupled induction circuit

15:47 <whitequark> whereas the QJE switcher has absolutely no problem over the entire operating range

15:47 <whitequark> whether in CV or CC mode, too

15:47 <sb0> hot tungsten + constant current is actually one of the best ways I've found to make that PSU oscillate and sometimes crash

15:47 <sb0> in CV, it's somewhat usable

15:47 <whitequark> crash is quite amazing. the one I had in Moscow didn't even have a micro

15:48 <whitequark> it had a voltage and current meters, just directly connected to the output, and some kind of adjustable feedback circuit

15:48 <sb0> that one does have a micro. and they went crazy trying to implement buggy/flawed gadget features with it

15:48 <whitequark> I'm glad to learn you can make a design even worse than that by adding an uP

15:49 <whitequark> the main drawback of the QJE is the ripple. it is quite bad when you draw less than 10mA

15:50 <whitequark> at some point you can hear it buzzing, even

15:50 <larsc> and here I'm wondering why a power supply would have a microphone

15:50 <whitequark> but once you get past miniscule currents, it doesn't have any unreasonable ripple or other problems that I have noticed

15:52 <whitequark> I'm itching to open the 60V15A and 15V60A versions of this QJE circuit, wonder how much it differs