#garfield Logs

Nov 11 2021

01:31 AM MoonyMoon: https://www.aliexpress.com/item/32974854462.html?spm=a2g0o.productlist.0.0.2eae36a6rGUF5V&algo_pvid=9ef1a231-57cd-4e4e-9062-7da050ab0183&algo_exp_id=9ef1a231-57cd-4e4e-9062-7da050ab0183-0&pdp_ext_f=%7B%22sku_id%22%3A%2266690462294%22%7D
01:39 AM rue_mohr: WormFood, meet moon
01:39 AM rue_mohr: moon, WormFood
01:39 AM WormFood: what?
01:39 AM WormFood: :P
01:39 AM * MoonyMoon !
01:39 AM MoonyMoon: hi
01:39 AM WormFood: Greetings MoonyMoon
01:39 AM WormFood: today is 11.11...so, big sales in China. That's like Chinese xmas
01:39 AM MoonyMoon: its rememberance day
01:39 AM rue_mohr: oh singles day
01:39 AM WormFood: the link to aliexpress reminded me of that
01:39 AM WormFood: double singles day
01:39 AM rue_mohr: I'll just order it and hope it arrives in the next year
01:40 AM rue_mohr: oh I'd better hurry then
01:41 AM MoonyMoon: sleep time, bye.
04:32 AM Tom_L: hi
08:48 AM aandrew: polprog: is EUR20 "net/hr" good for a kid in poland? (friend of a friend asking)
08:49 AM aandrew: rue_mohr / polprog : surprised neither of you had anything to suggest for my shitty battery simulator circuit :-)
08:50 AM aandrew: the general consensus is that chargers want a pretty low impedance "load" and the complementary pair-fed-opamp tends to be hard to stabilize without killing bandwidth, so the suggestion was to use power op-amps and/or parallel them with small series resistors instead of using transistors on the output
08:50 AM polprog: aandrew: it's allright, works out to 15k pln/month
08:51 AM polprog: whats the problem with battery simulators?
08:51 AM aandrew: it's oscillating like crazy, about 2v p-p and 16MHz
08:51 AM polprog: ouch
08:52 AM polprog: so 15k/mo is a starting pay for a programmer here
08:52 AM polprog: my Ni-cd charger was oscillating at first too :V
08:52 AM aandrew: not my circuit, I didn't think you should typically connect two BJTs like that without some matching magic on the bases, it's basically a class A amp IIRC
08:56 AM aandrew: I mean it's a battery simulator; it doesn't need more than what, maybe 1kHz bandwidth tops, I'm not sure why the two Qs in the feedback path would make it so unstable the opamp has a decent GBW and I'm not asking the world of it
01:21 PM rue_mohr: why didn't I see the battery simulator?
01:22 PM rue_mohr: aandrew, did you see how the oscillation was quenched in that audio opto isolator I did?
03:38 PM polprog: Im reading about class F oscillators
03:38 PM polprog: https://sci-hub.se/10.1109/22.644215
03:39 PM polprog: which took me wayyyyy to long to figure out that it's a class F amplifier (what the heck is a class F amplifier? now i know) configured as an oscillator :D
03:40 PM polprog: very interesting insight into CMOS behavior at millikelvin temps
03:40 PM polprog: https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8036394
03:45 PM polprog: gonna try to make a class F amp now at some point
04:03 PM Tom_L: hi hi
04:25 PM rue_mohr: hi
04:39 PM Tom_L: what you been workin on today?
06:06 PM rue_mohr: a silly distraction
06:07 PM Tom_L: too chilly for butterflies...
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210715.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210717.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210718.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210720.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210725.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210726.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210728.jpg
06:09 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1210729.jpg
06:09 PM rue_mohr: how about deer?
06:10 PM Tom_L: :)
06:11 PM rue_mohr: I used components from the board that was stripped to cut it out
06:13 PM Tom_L: what are you gonna do with it?
06:13 PM rue_mohr: I have no idea
06:13 PM Tom_L: hang it on your tree
06:14 PM rue_mohr: yea
06:14 PM rue_mohr: not sure if I can get room for a tree
06:14 PM rue_mohr: living room has filled in a bit
06:14 PM rue_mohr: I need to go shopping for milk and
06:14 PM rue_mohr: catfood
06:15 PM Tom_L: don't forget tea
06:15 PM rue_mohr: got tea, no milk
06:15 PM rue_mohr: really dont want to go shopping
06:15 PM rue_mohr: filled up the truck yesterday
06:15 PM rue_mohr: 3/4 of a tank for $100
06:15 PM rue_mohr: NEED A STEAM POWERED TRUCK
06:16 PM Tom_L: what's it cost a litre?
06:16 PM rue_mohr: I cant use low grade, so $1.83
06:16 PM Tom_L: it's like 3.09/gal
06:16 PM Tom_L: why not?
06:16 PM Tom_L: work truck?
06:16 PM rue_mohr: runs really badly
06:16 PM rue_mohr: no, its my truck
06:16 PM Tom_L: s10
06:16 PM rue_mohr: yea
06:17 PM Tom_L: hmm
06:17 PM Tom_L: you
06:17 PM Tom_L: 've had that a while
06:19 PM rue_mohr: yea
06:19 PM rue_mohr: you cant just buy cars here
06:19 PM rue_mohr: unless you have an extra $60k
06:19 PM Tom_L: nor here now
06:20 PM Tom_L: shortage up there too?
06:20 PM rue_mohr: a fellow at work had his car die
06:20 PM rue_mohr: he's had a hell of a time
06:21 PM rue_mohr: gonna go shopping
06:21 PM Tom_L: k
08:48 PM aandrew: heh I can smell that old circuit board being cut
08:54 PM aandrew: rue_mohr: no I don't remember seeing that
08:54 PM aandrew: (the audio isolator oscillation stopper)
09:55 PM rue_mohr: yea, I'm still trying to quench the stench
09:55 PM rue_mohr: aandrew, did you see the thread on the PC817 optic audio isolator?
09:57 PM Tom_L: hang the reindeer by the CD snowflake
10:01 PM rue_mohr: heh
10:01 PM rue_mohr: I hand cut it tho
10:01 PM rue_mohr: I was going to cnc it
10:01 PM Tom_L: no cnc?
10:01 PM rue_mohr: it would have come out better I think
10:01 PM rue_mohr: I was going to
10:01 PM rue_mohr: it *just* fits
10:12 PM aandrew: I don't think I saw it, no
10:12 PM rue_mohr: oh dear
10:13 PM Veil is now known as MrTime
10:13 PM MrTime is now known as TimeTop
10:16 PM rue_mohr: https://twitter.com/RueNahcMohr/status/1452806233283465217
10:16 PM rue_mohr: its awefull, you search for almost anything electronics related and all my posts come up
10:16 PM rue_mohr: 3rd hit for "PC817"
10:19 PM Tom_L: i doubt most of the twitter bunch is much into elecronics
10:19 PM rue_mohr: there are a number of them
10:19 PM Tom_L: percentage is low
10:20 PM rue_mohr: but that doesn't account for about 1890 of the 1897 followers
10:21 PM Tom_L: what OD is that tube?
10:21 PM rue_mohr: 1" iirc
10:22 PM rue_mohr: technically a 3/4" tube
10:22 PM rue_mohr: iirc
10:22 PM rue_mohr: its hard to find
10:23 PM rue_mohr: Tom_L, are you aware of the neon ring counters?
10:23 PM Tom_L: no
10:23 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/local_stock/18.jpg
10:24 PM rue_mohr: oh cool little cascade circuit
10:24 PM rue_mohr: the tube we use for that seems to be a funny size
10:24 PM Tom_L: i don't remember what i measured
10:24 PM rue_mohr: its schedule 5 ?
10:25 PM rue_mohr: said on one of the sections we got
10:25 PM rue_mohr: we just go by internal and external dimensions
10:27 PM rue_mohr: aandrew, how often do you check up on twitter anyhow?
10:29 PM rue_mohr: oh, a 1 day weekend kinda sucks
10:29 PM Tom_L: is that why you were off today?
10:30 PM rue_mohr: yup
10:30 PM Tom_L: some place that's closed on the weekend?
10:30 PM rue_mohr: ?
10:30 PM rue_mohr: thursday was a holiday
10:30 PM rue_mohr: back to work tommorow
10:30 PM Tom_L: that you need to work the weekend
10:31 PM Tom_L: mmm
10:31 PM rue_mohr: no
10:31 PM rue_mohr: today was a day off
10:31 PM rue_mohr: its like a 1 day weekend
10:31 PM Tom_L: 1 day weekend..
10:31 PM Tom_L: oh
10:31 PM Tom_L: nevermind
10:31 PM rue_mohr: then I have a 1 day workweek
10:31 PM rue_mohr: then a normal weekend
10:31 PM Tom_L: it's just a trial. pick the one you like best after the trial ends
10:32 PM Tom_L: at least we bunch our holidays to include the weekend
10:33 PM rue_mohr: yea
10:33 PM Tom_L: save for thanksgiving
10:34 PM Tom_L: it's always on a thursday
10:34 PM Tom_L: so we just set aside 4 days to over eat
10:35 PM rue_mohr: this was thanksgiving
11:10 PM aandrew: Tom_L: wow that's a lot of bar stock
11:13 PM aandrew: rue_mohr: I try to look every day but this last few weeks are rough
11:14 PM aandrew: 5 active contracts and 3 of them want 40h weeks
11:21 PM rue_mohr: I'm only following 127, and its a bit of labour to keep up with sometimes