#garfield Logs

May 19 2025

08:24 AM aandrew: rue_mohr: I fell asleep on the couch at like 9pm. don't know anything about wheelchair drive, and with no sensors the only way you could keep the wheels going teh same speed without a sensor would be some kind of mechanical link, no?
09:32 AM rue_mohr: na, you use backEMF
11:02 AM rue_mohr: https://tomverbeure.github.io/2023/01/29/Installing-Linux-GPIB-Drivers-for-the-Agilent-82357B.html
11:02 AM rue_mohr: aandrew, did you not see the backemf servo I did?
11:57 AM aandrew: I don't think so?
12:06 PM rue_shop2: how the hell di you miss that?
12:07 PM rue_shop2: someone in japan did it, and didn't really want to post the details, so I tried it, and, tho not quite as good, I kinda pulled it off..
12:07 PM rue_shop2: https://www.youtube.com/watch?v=iJDwuBfbN4A
12:09 PM rue_shop2: now I wait for you to get an execution slot so you can see it and generate a reply
03:42 PM rue_mohr: kicking myself a bit today
03:43 PM rue_mohr: I went to a lot of work to find some small(er) 120VAC coil relays on ali a while back, one of them was 110VDC (!?!?!). today I was going thru sorting out 24VDC relays and found like 10 120VAC ones
03:44 PM rue_mohr: I keep needing them for detectors and no-frills low current switch beef-ups
03:45 PM rue_mohr: seems I cant (yet) manage to fit a dropper circuit+24VDC relay into a cube smaller than a 120VAC relay
03:46 PM rue_mohr: you would think that a 48VDC relay would take half the current of a 24V, but it doesn't
03:46 PM rue_mohr: the 24V ones seem to be the lowest current coils available
06:02 PM aandrew: oh I saw that yes
06:03 PM aandrew: what's a "dropper circuit" ?
06:03 PM aandrew: some of those 120VAC relays I used have a very detectable switching time, flip the switch off and the lights flicker for a moment before they transition correctly
06:03 PM aandrew: might try some of the others I got
07:19 PM rue_shop2: no theats the lamp driver
07:19 PM rue_shop2: the new led drivers suck, their inrush limiting and they take up to 1 sec to turn on
07:20 PM rue_shop2: dropper circuit, so, 120VAC -> 9VDC non-isolated using mostly capacitor reactance
07:20 PM rue_shop2: you put a bit of resistance in there to limit inrush on bad events
07:21 PM rue_shop2: I made a chart you would have seen at some point that showed what capacitor value to get for the max output current you need
07:24 PM rue_shop2: for example, using a full bridge (smaller cause 4 diodes in 1 part) and a 1uF cap to get 24V will give you a peak current of 34mA
07:25 PM rue_shop2: so if you need 24V at LESS than 34mA you stick a zener across it and your always good
08:12 PM aandrew: I remember playing with that for a stupid simple triac controller a long time ago
08:12 PM aandrew: capacitive reactance is kind of weird
08:12 PM rue_mohr: mmm
08:12 PM rue_mohr: phase
08:14 PM rue_mohr: ok, I need to make up another dip8 ch32
08:14 PM rue_mohr: ok, I can do this
08:15 PM rue_mohr: how the hell do I defeat motivation issues
08:15 PM rue_mohr: getting a room mate again soon, maybe that will do it
08:15 PM rue_mohr: told myself living alone would be hard on me
08:15 PM rue_mohr: I think I'v done ok
08:15 PM rue_mohr: only about half crazy
08:17 PM aandrew: oh? that'll be a change
08:17 PM aandrew: motivation issues are hard
08:18 PM rue_mohr: yup, I should be done the motor thing I set out to do today
08:18 PM aandrew: for me sometimes I just need to break a task down to ridiculously simple tasks so I can say I did *something* and that tends to help spur me to move to the next ridiculously small task
08:19 PM rue_mohr: I think I have a lot of issues that outline "depression" and meh, I dunno, can I go back to sleep now?
08:26 PM aandrew: that kind of stuff requires medical attention. I don't try to recommend or give any kind of advice in that kind of stuff. It's often unhelpful and can be dangerous
08:28 PM rue_shop2: but I'm not like sad depressed
08:28 PM rue_shop2: I'd just rather go back to sleep
08:28 PM rue_shop2: and sleeping doesn't do anything about that feeling
08:28 PM rue_shop2: so, obviously not a proper self-regulating issue
08:29 PM rue_shop2: trying to stay awake doesn't do any good, I just become a zombie
08:29 PM rue_shop2: and part of what I dont get, is that I'm blaming it on being alone, BUT I'v always been alone!
08:30 PM rue_shop2: you know the song lyric, "alone in a crowd" well, thats me
08:31 PM rue_mohr: '
08:31 PM rue_mohr: I'v lived my life with people telling me to stop being different, but, thats not how it works. I'm not being different, different is being me
08:41 PM rue_mohr: and sometimes, the harder I push to stay awake, the more tired I get
08:45 PM rue_mohr: I dont really get how on the ch32, the swio pin is basically always ready to take programming.
08:48 PM rue_mohr: YAY, I put a ch32 on a carrier, programmed it, and its working!
08:48 PM rue_mohr: the 8 pin versions are a bit intersting as they ... merge lots of the IO pins
08:48 PM rue_mohr: some of the pins are not gpio by default
08:49 PM rue_mohr: apparently these ch32 can output like 20mA per pin to a max of 80mA
08:49 PM rue_mohr: well, sink 80mA source 100mA
08:49 PM rue_mohr: so, the 8mA I'd need to drive the opto isolators is ok
08:49 PM rue_mohr: so, I dont need a lot of parts for this...
08:52 PM rue_mohr: actually, as I'm tired I better take a nap, I'm on-call and if I have to drive out to town like I am its not ideal
08:53 PM rue_mohr: I been pondering putting a matress on the floor for a work/sleep space
08:53 PM rue_mohr: soldering in bed might not be a good idea
08:54 PM rue_mohr: oh I need a power supply
08:55 PM aandrew: rue_mohr: depression manifests in several different ways, and just wanting to sleep is one of them
08:55 PM rue_mohr: yea, but what I dont get, is why would I be depressed
08:55 PM rue_mohr: there are a lot of POSSIBLE reasons, I dunno
08:56 PM aandrew: not to put too fine a point on it but I've noticed some of your ramblings here that made me a little concerned about your well being. Nothing overt, just a kind of sense of it
09:26 PM rue_mohr: no fair, most of the time, besides I, me, and myself, there is NOBODY available to talk to
09:27 PM rue_mohr: I would be so cool to have a pool of peers to just drop in and chat with anytime
09:27 PM aandrew: yep. you're pretty damn remote and your hobbies/interests are kind of esoteric so... that becomes problematic
09:31 PM rue_mohr: but, nothing changed, so, wtf? right?
09:31 PM rue_mohr: going to sleep so I'm better off driving if a call comes in, bbl
10:35 PM rue_mohr: it wont go to sleep
10:35 PM rue_mohr: ok, ...
10:36 PM rue_mohr: I need a solution for little power converters
10:36 PM rue_mohr: I want to make
11:24 PM rue_mohr: did up a spreadsheet
11:24 PM rue_mohr: not perfect but
11:24 PM rue_mohr: if I want to make a dc-dc converter, using pushpull, with pn2222 as power transistors
11:25 PM rue_mohr: if I want to take 1.5V to 5V, I might be able to get a peak of 131.5mA out, and I should use a 300 ohm base resistor max
11:25 PM rue_mohr: if I have 12V and want to get 15V, 382mA, and 2.4k
11:26 PM rue_mohr: I'm trying to establish a stupid-simple power converter
11:28 PM rue_mohr: with random cores
11:29 PM rue_mohr: when I was playing with cores I found two quite distinctly different types
11:30 PM rue_mohr: one of them was prettymuch always fine by about 70kHz, the other was saturating right up to about 120kHz
11:30 PM rue_mohr: or was it 7khz
11:30 PM rue_mohr: well, I can play again
11:30 PM rue_mohr: but rando cores are the goal
11:31 PM rue_mohr: I need a better feel for saturation in context of turns count
11:31 PM rue_mohr: I think more turns will saturate faster
11:32 PM rue_mohr: At*time
11:35 PM rue_mohr: ok, chatgpt...