#garfield Logs

Oct 21 2019

08:28 PM rue_bed: full 8 hours working in the rain
08:49 PM Tom_L: fun
08:49 PM Tom_L: make some hot tea
08:54 PM rue_bed: yea, and changed, and dried, and chilling
08:55 PM rue_bed: hmm
08:55 PM rue_bed: ~7pm
08:55 PM rue_bed: if I take something to wake me up now, I might be up all night
08:56 PM rue_bed: want to work on my stm32 project
08:56 PM rue_bed: next step is to change up the freq meter code to do really low freqs
09:55 PM TELunus: rue I'm not seeing a jumper or switch for 120V https://photos.app.goo.gl/nrTNYi1bRAHfAoFN8
10:07 PM rue_mohr: hi
10:09 PM rue_mohr: TELunus, wow what corrupted that image!
10:10 PM rue_mohr: its gota PFC circuit, did you try it on 120?
10:11 PM TELunus: https://imgur.com/a/Kv3sOLp
10:11 PM TELunus: Just plug it in and see what happens?
10:12 PM rue_mohr: let me look a bit more
10:12 PM rue_mohr: no the src image is correupt
10:12 PM rue_mohr: can you retake it?
10:13 PM rue_mohr: its all doubel iamged on the top
10:13 PM TELunus: Oh, yeah that's 'cause I tried to use google's "Photo Scan" app, but I guess it expects flat subjects.
10:14 PM rue_mohr: ?
10:14 PM rue_mohr: dont let anyone post-process an image...
10:14 PM rue_mohr: every time I see youtube stabilization, I want to send them a bag of barf.
10:15 PM rue_mohr: makes me seasick
10:18 PM TELunus: https://photos.app.goo.gl/ZBfKsMrbkRuZsqzD9
10:21 PM rue_shop1: interesting/strange
10:22 PM rue_shop1: can you get a pic of the back?
10:23 PM rue_shop1: it almost looks like they used the backlight transformer for the other power supplies
10:24 PM rue_shop1: they have a power factor correction system, but its not large enough to need it...
10:26 PM TELunus: Like the back of that PCB? I could unscrew it I guess.
10:26 PM rue_shop1: if its not had power in more than 8 hours it should be fine
10:29 PM rue_shop1: 0000500mHz
10:29 PM rue_shop1: my freq meter is working :)
10:30 PM TELunus: Nice!
10:30 PM rue_shop1: ugh, 150mHz takes a while to read...
10:43 PM rue_mohr: see where it gets sketchy, I think about 3kHz
10:44 PM rue_shop1: ah, hmm, I need a different print function
10:45 PM rue_shop1: flutter is 6hz at 15kHz
10:46 PM TELunus: https://photos.app.goo.gl/77BF6BHrJPotuoDj6
10:46 PM rue_shop1: hmmm
10:48 PM rue_shop1: oh wow
10:49 PM rue_shop1: their PFC transofrmer is almost the same size as the power transofrmer
10:50 PM rue_shop1: so, there are two power supply controller chips in there
10:50 PM rue_shop1: one runs the little transformer thats for standby power
10:50 PM rue_shop1: and the other runs the long transformer thats for everything
10:50 PM rue_shop1: the 3rd square transformer is for power factor correction
10:51 PM rue_shop1: it boosts up voltage during the low parts of the AC
10:51 PM rue_shop1: both chips have whats called UVL, under voltage lockout
10:52 PM rue_shop1: meaning if there isn't enough voltage on the system yet, they wont start up
10:52 PM rue_shop1: I'd put it togethor and try it on 120
10:52 PM rue_shop1: if it wont work, then I'd go with a 2:1 transformer
10:52 PM TELunus: K, I'll give that a shot.
10:53 PM rue_shop1: make sure the VA rating of the transformer is twice the wattage of the TV
10:53 PM rue_shop1: so, if its a 20w tv, go with a 40VA transformer
10:53 PM rue_shop1: (if you even have to)
10:59 PM rue_shop1: ok, 0.1% ends around 36kHz
11:27 PM TELunus: I just tried it out. It works fine, but I had thought I'd heard it was 4k, but it definitely doesn't seem to b.
11:27 PM TELunus: seem to be*
11:31 PM rue_mohr: k
11:32 PM rue_mohr: keep an eye on it for "a hot smell"
11:32 PM rue_mohr: the converter might be working hard to operate at 120, if so, probably not good on 120 for a long time
11:37 PM TELunus: Alright. Well, I've disconnected it for now. I was using my main computer to test it, and my primary monitor is better in a bunch of ways, so I'll leave it for now and maybe look at switching it with the TV in the living room in a bit.
11:46 PM rue_mohr: yup
11:47 PM rue_mohr: 4k is nothing about resolution, its about colour
11:47 PM rue_mohr: even 1080 shouldn't compare ot your monitor
11:47 PM zhanx: here but code mentoring in sparkfun
11:51 PM rue_mohr: I think I'm running 1600x1200
11:53 PM rue_mohr: yea 1600x1200