#garfield Logs

Oct 31 2022

02:25 PM rue_mohr: 3173
02:35 PM rue_mohr: numbers are different, but not by much, ok
02:35 PM rue_mohr: its not going down...
02:35 PM rue_mohr: dont get that
02:35 PM rue_mohr: no feedback on the book :/ oh well
03:42 PM rue_mohr: sunny day cut down trees, rainy day, wash truck
03:42 PM rue_mohr: I should have washed the truck yesterday
03:42 PM rue_mohr: :/
06:29 PM Tom_L: had linux lose it's brains on the ssd today
06:29 PM Tom_L: got it back but wouldn't boot for some reason for a bit
07:37 PM rue_shop3: ?
07:37 PM rue_shop3: I'm gonna bet the SSD is failing
07:37 PM rue_shop3: working on designing this power converter for the driveway lights
07:37 PM rue_shop3: I think I'm starting to get it
07:38 PM rue_shop3: I have a formula that relates voltage and frequency to saturation on a core
07:38 PM rue_shop3: cores saturate at an amp-turn level
07:38 PM rue_shop3: which is reflected in driving them with votlage due to the charge slope
07:39 PM rue_shop3: different cores have a different inductance, so the curve to saturation is different
07:39 PM rue_shop3: if they have a really high inductance, then its pretty flat slope till they saturate
07:39 PM rue_shop3: if you know that amp*turns ratio
07:40 PM rue_shop3: you can working out the maximum number of turns to put on, say the secondary
07:40 PM rue_shop3: so I'm doing 12V at 24w
07:40 PM rue_shop3: secondary current of 2A
07:40 PM rue_shop3: the core I'm evaluating saturaes at 10At
07:40 PM rue_shop3: which means I can have a max of 5 turns on the secondary
07:41 PM rue_shop3: with everything, it works out to about 700mA on the primary
07:41 PM rue_shop3: but I'd need 20 turns on the primary for that
07:41 PM rue_shop3: and that comes out to 14At
07:41 PM rue_shop3: which wont work
07:43 PM rue_shop3: --
07:43 PM rue_shop3: if I reduce the secondary to 4 turns
07:43 PM rue_shop3: 8At on the secondary
07:44 PM rue_shop3: 16 turns on the primary
07:44 PM rue_shop3: 11.2At
07:44 PM rue_shop3: still too high
07:44 PM rue_shop3: this core isn't gonna work
07:45 PM rue_shop3: well, if I could run it at like 1MHz, but I cant do that
07:45 PM rue_shop3: at 16t primary, the freq is...
07:45 PM rue_shop3: oh, 15kHz
07:45 PM rue_shop3: hmm
07:45 PM rue_shop3: ok, lets push farther
07:45 PM rue_shop3: --
07:46 PM rue_shop3: secondary to 3 turns, 6At
07:46 PM rue_shop3: primary at 12 turns,
07:46 PM rue_shop3: 8.4At
07:46 PM rue_shop3: it clears saturation
07:47 PM rue_shop3: freq is...
07:47 PM rue_shop3: 20kHz
07:48 PM rue_shop3: kinda high, but
07:51 PM Tom_L: the ssd is new
07:51 PM Tom_L: may have been a bios burp too
07:51 PM Tom_L: i switch things around on it quite a bit
07:51 PM rue_shop3: meh, both SSDs I had failed in a month
07:52 PM Tom_L: i trust these a bit more than some
07:52 PM rue_shop3: mhm
07:52 PM Tom_L: it's been fine since i got it back up
07:57 PM rue_shop3: ugh, there is a 2 in these equations that keeps stabbing me
07:57 PM rue_shop3: Tom_L, yes, they work by remapping failures to different areas of memory
07:57 PM rue_shop3: but may lose the data at the memory that failed
07:58 PM rue_shop3: smartctl -a /dev/sda
07:58 PM rue_shop3: if its installed, will tell ya
07:58 PM Tom_L: i know
08:02 PM rue_shop3: from what I understand, at what should be the operating point, I'm losing 1.4w on the fore
08:02 PM rue_shop3: core
08:02 PM rue_shop3: its a 24w converter
08:02 PM rue_shop3: 94%
08:03 PM rue_shop3: get a bit worse with more windings
10:25 PM Tom_L: did dude still have the drill?
10:25 PM rue_mohr: arg, I knew I forgot to check something