// #eevblog — 2020-12-24
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00:03:16 Join: Kuschelpony ([email protected]) to #EEVblog
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01:14:40 <electrohead> o/
01:15:30 * Ampera hugs electrohead
01:15:32 <Ampera> how are you doing electrohead
01:17:09 <electrohead> resisting the urge to call the local VA back, as they are finally calling me to schedule an appointment
01:17:27 <electrohead> took them over three months, and me reporting them to the VA OIG...
01:17:33 <electrohead> so, I may wait three months myself, now
01:17:36 <electrohead> ;D
01:18:09 <electrohead> but, I'm good, you?
01:18:31 <Ampera> electrohead, alright, today's technically christmas for me
01:30:32 <electrohead> what all did you get for yourself?
01:30:33 <electrohead> :P
01:39:02 <Ampera> electrohead, Today's a compromise, my dad has a new family, but I managed to get today to be a day his obsolete one can at least have a christmas
01:41:09 <K> oh.
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04:33:06 <T3sl4> huh, this ToT vid only has 887 views on it. oh, it was posted two minutes ago
04:34:41 <K> weak.
04:39:03 <T3sl4> https://www.youtube.com/watch?v=f9qN9LIChh4
04:41:23 <K> huh,
04:41:31 <K> i think it is enough of work this year
04:44:02 <T3sl4> agree
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05:27:19 <TheDude> hey
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05:58:35 <arch> i want to use a 2n3904 as a PN-drop transistor temperature sensors (so the ~2mV/C, at low currents). i don't really need UBER accuracy, so how good would this type of constant current source work? https://i.imgur.com/6NZuLw3.png
05:59:11 <arch> or rather, how well*, pardon my french
06:02:44 <arch> ya know what, i think let me do this on breadboard so i can judge for myself
06:03:07 <arch> i dont really care about +/-5C error
06:03:35 <arch> as long as it's not +/-10C, i'd be more than happy
06:03:46 <Kuschelpony> the "constant" current would obviously drop with temperature
06:04:05 <arch> yeah, but not by much
06:04:28 <Kuschelpony> if the source circuit and the sensor transistor are close together on the same temperature this might work better
06:04:41 <Kuschelpony> i think its worth to try
06:04:48 <Kuschelpony> but keep the supply voltage stable
06:05:51 <arch> say the bjt drop is 0.7V at 25C; at 80C, it would be (80C - 25C)*(2mV) less, or 0.11V lesser, so 0.6V drop, the current would become slightly lower, 1mA about
06:06:09 <Kuschelpony> as said, i think its worth to try
06:06:37 <arch> and yea, the sensor will be far from the board
06:06:37 <Kuschelpony> i have to go off for something 20 minutes, dontz worry
06:06:52 <arch> but im sure this will work nicely
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06:07:05 <arch> even with the offset at higher temp, it'd be very minor
06:07:39 <arch> i need ballpark figures, not 0.0000001% error :D
06:19:24 <arch> so i'm going to do two tests: one where i have every component on that design close together, and blast everything with 100C from my hot air gun; second test where i have the current source far away, and blast the temperature sensing transistor itself with 100C hot air
06:19:40 <arch> and measure the voltage drop at the sensing transistor
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06:51:51 <DHess_US> "Hey thanks to ever broke into our car last night just to find out there was nothing in it except for our masks and stealing them LOL we have Covid so enjoy!"
06:52:17 <DHess_US> arch, look up "delta vbe temperature sensor"
06:53:24 <DHess_US> If you want to be really clever, you can do triple delta vbe, https://www.electronicdesign.com/technologies/analog/article/21762159/triplecurrentmodulation-delta-vbe-thermometry-cancels-ohmic-error-sources
06:53:53 <TheDude> arch, would be useful if you told us what you're going to need to measure the temperature for
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07:15:36 <hsn> I recieved my flower seeds
07:17:43 <hsn> DHess_US: this makes me wannaCry that i dont know how class A bjt amplifier work and u share this stuff lol
07:20:29 <DHess_US> hsn, page 7 here, https://www.analog.com/media/en/technical-documentation/application-notes/an45f.pdf
07:23:03 <hsn> Thx i ll save it and read after i teach my self more about bjt
07:27:24 <DHess_US> The Tektronix 7M13, DM501, and DM502 all have delta vbe thermometer circuits and are fully documented if you want examples that use analog switches.
07:32:59 Join: rust_collector ([email protected]) to #EEVblog
07:39:01 <hsn> DHess_US: https://www.instagram.com/p/CJCd-iTreTd/?igshid=162kttz6h4ydi this for my level
07:39:26 <DHess_US> link broken
07:40:05 <rust_collector> it works here
07:40:34 <DHess_US> All I get is login screen.
07:40:47 <DHess_US> Instagram is broken by design.
07:41:10 Quit: Kuschelpony ([email protected]) Connection closed
07:41:11 <coppice_> it matched the broken users
07:45:48 <hsn> DHess_US: https://photos.app.goo.gl/uLzam9gzGmgU6c8QA
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08:40:16 <electrohead> o/
11:10:00 Join: Nothing\ ([email protected]) to #EEVblog
11:10:18 <Nothing\> hey all, scott here
11:10:21 <Nothing\> i mean, Nothing\
11:10:33 * Nothing\ still waits for someone to get that
11:10:52 <Nothing\> and to hopefully read that in scott's voice
11:21:11 Join: arch ([email protected]) to #EEVblog
11:22:39 <arch> measure temp of a heatsink TheDude
11:23:17 <TheDude> do you need it to be accurate or are you just controlling a fan or something?
11:23:52 <arch> just need ballpark figures so i can activate a cooling fan
11:24:11 <arch> anything up to +/-10C accuracy is fine by me
11:24:23 <TheDude> why not a NTC?
11:24:46 <TheDude> you can get them packaged with a lug that you can screw onto the heatsink
11:25:10 <arch> that sounds nice yea
11:25:14 <arch> lemme see...
11:27:43 <arch> yeah it should work, i just have to make some minor changes. cool. that takes care of that then. let me just do a quick experiment to see how accurate the basic current source + bjt sensor is though, for science
11:29:10 <arch> oh wait, for the NTC method, i'd need a stable voltage reference. i think a TL431 2.5V ref should be good
11:29:25 <TheDude> nope, not really
11:29:35 <TheDude> in fact, it doesn't need to be accurate at all
11:30:55 <arch> isnt the voltage gonna vary if i hook it up to Vcc? USB cable lengths gonna change up the voltage from resistance drops
11:31:29 <TheDude> yes, but you're only interested in the ratio between the resistances
11:31:55 <TheDude> I can make a circuit in ltspice if you'd like that
11:31:58 <arch> i need to feed the voltage to an ADC
11:32:07 <TheDude> oh, hold on
11:32:14 <TheDude> you want it controlled by a microcontroller?
11:32:30 <TheDude> I thought you just wanted a simple analog solution
11:33:09 <Nothing\> weird
11:33:09 <arch> yeah, this is going in an arduino project. im working on a constant current/power/resistance load. it's pretty neat, although the guy used too many expensive chips where there is no reason to
11:33:30 <Nothing\> i was just looking on google earth. there's something censored out less then a block from the champs elysees
11:33:32 <TheDude> can you link the project?
11:33:50 <Nothing\> but it still let's you go into street view
11:33:52 <arch> https://www.instructables.com/Arduino-Programmable-Constant-Current-Power-Resist/
11:34:29 <arch> idk what was the point of using two LM94022 temp sensors
11:34:50 <arch> that's a solid $3 savings right there using discrete or simpler parts
11:34:56 <Nothing\> i'm not sure what it is, but i have some LM series IC that's a temp sensor
11:35:08 <Nothing\> definitlely not a 94022
11:35:49 <Nothing\> omg bowel cramps galore this "morning"
11:36:01 <Nothing\> no word of a lie, i had 4 shits when i woke
11:36:03 <Nothing\> up
11:36:09 <arch> you have a serious obsession with pooping, more so than me
11:36:13 <Nothing\> all of them absolutely solid
11:36:15 * arch poops on T3sl4's front yard
11:36:23 <Nothing\> arch, everybody poops...
11:36:25 <Nothing\> blood
11:37:04 <Nothing\> it's a belarusian children's book from 1984
11:37:29 <Nothing\> wink wink nudge nudge
11:37:45 <Nothing\> (they were affected by chernobyl)
11:37:57 * electrohead always comes into the channel at weird times
11:38:10 <Nothing\> electrohead, every time i'm in here is a weird time
11:38:10 <arch> lol
11:38:17 <Nothing\> so i made a good find yesterday
11:38:24 <electrohead> lol
11:38:27 * electrohead waves
11:38:28 <Nothing\> got metroid: return of samus on 3ds for $30
11:38:44 <Nothing\> i've been waiting for it to come down in price since i was released, and all it did was go up
11:38:57 <Nothing\> so finally i found a used copy for a decent amount
11:39:05 <arch> i have a hacked 3DS. actually, all my consoles are hacked
11:39:18 <arch> that's my primary factor when i consider buying a console :D
11:39:25 <Nothing\> arch: lol i actually got a flashcart for me 3ds
11:39:28 <TheDude> I took a look at the schematic
11:39:34 <Nothing\> paid like $105 for it, right
11:39:41 <TheDude> ... it's not terribly great, to be quite honest
11:39:48 <Nothing\> while it was shipping, nintendo released an update that rendered it useless
11:39:53 <arch> right, it could use some work
11:40:01 <arch> it's got a lotta unnecessary crap in it
11:40:09 <Nothing\> i have a hacked Wii, that's enough for me
11:40:18 <Nothing\> wish i could hack my switch though, tbh
11:40:24 <Nothing\> the games are so expensive
11:40:41 <Nothing\> i musta spent close to $2000 on it plus the games since i got it a year and a half ago
11:40:51 <Nothing\> probably more like $1500 but still
11:40:53 <arch> which is exactly what im gonna do--remove a buncha crap. important for me to save those $3-5 here and there, and i'll also be etching it on copperclad too :D
11:41:31 <Nothing\> most of the games were ones i could have easily pirated, but as i was using a pi 3 as my primary computer for 2 years, this was not possible.
11:41:38 <TheDude> it's not even that much about the cost
11:41:46 <TheDude> some design decisions in there are just purely bad
11:41:51 <arch> examples?
11:41:57 <TheDude> if you'd like, we can go through it
11:42:01 <Nothing\> TheDude, i know what you mean
11:42:13 <TheDude> first there is the power source switching
11:42:24 <TheDude> a relay seems like a ridiculously wasteful choice
11:42:26 <arch> yep, which is why i'm using just ONE source
11:42:28 <Nothing\> like i got terraria for p3s, it was perfect aside from the fact that they stopped making new content for it cuz it was ps3
11:42:39 <Nothing\> so i got the version on switch
11:42:45 <Nothing\> and it was literally unplayable
11:42:46 <arch> just plain old USB, AND, to be safe, im using a USB load switch with soft start
11:42:51 <Nothing\> the controls were so fucking broken
11:43:05 <Nothing\> i died after the first enemy i tried taking out with a ranged weapon
11:43:22 <arch> im using this load switch https://www.diodes.com/assets/Datasheets/AP22815-615.pdf
11:43:26 <Nothing\> i've actually hade a few switch games where the controls were that broken
11:43:47 <Nothing\> i haven't had to deal with broken controls since the day of the NES
11:44:31 <Nothing\> but yeah, most of the time, with pc games at least, i'll pirate them and try them first to make sure there aren't any major problems
11:44:47 <arch> TheDude, im also not a fan of the ON-or-OFF cooling fan solution. im gonna add in code to control a 4-pin PWM fan
11:44:52 <TheDude> okay then next
11:44:55 <arch> so it ramps up or down
11:45:17 <Nothing\> then i'll get em on steam if i deem them worthy of purchase, mostly for the sake of keeping it up to date without having to remember and do manual checks and hope they uploaded the most recent version to tpb
11:45:41 <TheDude> buffer amplifiers before the ADC
11:46:02 <TheDude> huge capacitive load straight onto the output of the amplifier
11:46:17 <TheDude> that's going to suck for stability
11:46:45 <arch> wait a second, do we even NEED buffering? how much current do those ADCs need
11:46:51 <arch> the inputs at least
11:46:54 <arch> lemme see
11:47:01 <TheDude> no, the thing is
11:47:08 <TheDude> ADCs have input sampling capacitors
11:47:29 <TheDude> that get connected and disconnected from the inputs
11:47:37 <arch> interesting, i did not know that. i wonder if the block diagram shows it
11:47:55 <TheDude> so even though those sampling capacitors are really tiny, it's going to skew the result unless you have some capacitance at the input
11:49:38 <arch> so skip the caps since they are built in?
11:49:53 <TheDude> no, absolutely not
11:49:54 <TheDude> hold on
11:50:41 <TheDude> https://www.planetanalog.com/optimizing-sar-adc-driver-amplifier-and-rc-filter-circuit-settling-using-spice/#
11:50:57 <TheDude> and hold on, let me check the ADC's datasheet first
11:51:04 <Nothing\> oh hey
11:51:21 <Nothing\> did i show you guys what my mom got me for an early xmas gift?
11:51:38 <Nothing\> https://ibb.co/tHzcbB8
11:51:40 <arch> wot in tarnation, i have no idea what's going on in that article
11:51:58 <Nothing\> one of the best gifts i've ever gotten
11:52:26 <TheDude> https://ww1.microchip.com/downloads/en/DeviceDoc/21298e.pdf
11:52:29 <TheDude> page 18
11:53:03 <TheDude> okay, quick fix for this then
11:53:28 <TheDude> reduce the input capacitors to like 4.7n
11:53:48 <TheDude> and add a resistor between the input capacitor and the buffer amplifier
11:54:03 <TheDude> 47-100 ohms
11:54:42 <arch> boom, and boom. done. thanks TheDude :D i've been saving my old, dead graphics card for ~4 years because i knew i'd make a project with it one day
11:54:48 <arch> GTX580 lol
11:55:02 <arch> i'm gonna be using it as-is, and strapping all that circuitry underneath
11:55:14 <TheDude> err
11:55:16 <arch> obviously, i cut out the GPU using a dremel earlier
11:55:20 <TheDude> you're using the heatsink then? :D
11:55:27 <arch> no, literally the whole GPU itself
11:55:44 <arch> the card and its heatsink
11:55:54 <TheDude> okay
11:56:00 <TheDude> we're not done with the circuit, though
11:56:32 <arch> im not using those two LM94022s; using NTC + TL431 reference, or maybe the 2.048V reference also works
11:56:43 <TheDude> err
11:56:49 <TheDude> you don't need a reference with an NTC
11:56:59 <TheDude> the measurement can be completely ratiometric
11:57:16 <arch> ooh, i'm new to that idea. let me do some quick googling
11:57:21 <TheDude> just make sure you're powering the resistive divider with the same voltage that you're using as the ADC reference
11:57:35 <TheDude> I can exmplain
11:57:38 <TheDude> explain*
11:58:03 <TheDude> an ADC gives you a number that tells you how large an unknown voltage is proportionally to the reference voltage
11:58:14 <TheDude> so if you have a 12-bit ADC
11:58:34 <TheDude> the code output is going to range between 0 and 4095
11:59:05 <arch> right
11:59:05 <TheDude> so 2048, for example, would mean that you're measuring 1/2 of the reference voltage
11:59:20 <arch> with ya so far
11:59:34 <TheDude> if you're powering the voltage divider with the same reference voltage, you're just going to measure the proportion of voltage you're seeing
11:59:47 <TheDude> so it doesn't matter what that voltage is in absolute terms, because it cancels out
12:00:05 <TheDude> the output code of the ADC depends just on the ratio between the fixed resistor and the NTC
12:00:25 <TheDude> this is what is called a ratiometric measurement
12:02:08 <arch> do you have a schematic so i can understand this concept a bit better
12:02:51 <Nothing\> here we are
12:03:00 <TheDude> i'll find something, hold on
12:03:04 <Nothing\> i was talking about that other temperature sensor i had in the LM series
12:03:11 <Nothing\> i just dug it up, it's an LM35
12:03:13 <Nothing\> https://www.ti.com/lit/ds/symlink/lm35.pdf
12:03:24 <Nothing\> if that's helpful at all
12:03:48 <Nothing\> if not, just disregard :)
12:03:57 <arch> nah, im not gonna use that. the point is to cut down fat and go cheapie
12:04:11 <Nothing\> those aren't cheap?
12:04:19 <arch> not in small quantities
12:04:23 <Nothing\> actually i guess not, no
12:04:31 <Nothing\> yeah i was gonna say i paid over $1 for just 1
12:04:54 <arch> i don't have a need for dozens of temp sensors. i don't mess with temp sensing projects all too often :D
12:05:02 <Nothing\> i should make a circuit with one of these tonight
12:05:09 <TheDude> https://www.maximintegrated.com/en/design/technical-documents/tutorials/6/685.html
12:05:11 <arch> and even if i did, im sure i would be a cheap bastard and use either NTC or transistor sensing
12:05:16 <Nothing\> i have all of these hundreds of chips, but i've never used like 99% of them
12:05:33 <Nothing\> i just bought whatever seemed like it may be useful in the future
12:05:40 <TheDude> arch, figure 1
12:06:18 <Nothing\> that reminds me
12:06:38 <arch> but this is assuming the Vref is equivalent to the ADC's supply voltage. in the schematic, he uses a 2.048V reference, no? it's separate, right?
12:06:39 <Nothing\> i found a new (to me) circuit simulator online thta runs in your browser. It seems very similar to Spice.
12:07:10 <TheDude> as long as the reference isn't buried inside the silicon, you can use it
12:07:10 <Nothing\> here it is
12:07:11 <Nothing\> https://www.circuitlab.com/editor/#
12:07:20 <TheDude> just make sure that you don't overload it
12:07:26 <Nothing\> it seems like it has a great deal of potential
12:07:39 Quit: ThunderSqueak ([email protected]) Quit: Leaving
12:08:01 <TheDude> I know I'm biased, but I honestly don't see much value in those online simulators
12:08:31 <arch> same here. i learn a lot better breadboarding or etching
12:08:51 <TheDude> that's best
12:08:54 <arch> ltspice looks spartan, but damn, it's a great tool
12:08:59 <TheDude> but there is value in simulators, just not the online ones
12:09:14 <TheDude> ltspice is the best among the free spice simulators
12:09:17 <Nothing\> oh yeah that's right
12:09:31 <Nothing\> the thing wants you to register for an account before it'll do any analyses
12:09:41 <TheDude> bugmenot.com
12:10:07 <TheDude> you can find already registered accounts on there that allow you to bypass the registration for these sorts of things
12:10:22 <Nothing\> TheDude, now that's useful
12:10:41 <Nothing\> in return, here's a "making of:" documentary about a clockwork orange
12:10:44 <Nothing\> https://www.youtube.com/watch?v=sYMgrYGkJ64&ab_channel=BehindTheScenes
12:11:03 <TheDude> ha, cool .d
12:11:06 <TheDude> :D*
12:11:14 <TheDude> buuuuut... we're not done with the circuit
12:11:17 <Nothing\> i was hoping you were a fan
12:11:28 <Nothing\> indeed, that can be viewed whenever. No rush.
12:11:33 <TheDude> yeah, watched the movie some time ago, it was good fun
12:11:38 <arch> TheDude, i'm still confused about this. in figure 1, it shows the ADC's reference AND its supply as being from Vcc. however, in the schematic for the cc load, it uses the reference provided by the ADR380, which is providing 2.048V. from this, are you suggesting that i power the NTC resistor-divider from the 2.048V reference?
12:11:47 <Nothing\> i don't expect you to drop everything you're doing so you can watch a 30 minute documentary on my account
12:11:55 <TheDude> arch, yes
12:12:15 <arch> TheDude, THAT'S WHAT I SUGGESTED IN THE FIRST PLACE >_<
12:12:23 <arch> but you were like NUUUU that's not what you do
12:12:27 * arch facewalls
12:12:30 <TheDude> just calculate how much current the divider is going to pull when the temperature is hottest
12:12:34 <Nothing\> man, one thing they never tell you you need in a an electronics lab is a flashlight
12:12:45 <Nothing\> or preferably a magnifying glass with a flashlight
12:12:57 <arch> i just use my smartphone with a tripod lol
12:12:58 <TheDude> arch, I thought you were going to use a dedicated voltage reference for measuring temperature
12:12:58 <Nothing\> but i find a flashlight makes it soooo much easier to read the writing on a chip
12:13:02 <TheDude> it's not needed
12:13:28 <arch> that ADR380 can supply up to 25mA btw, so i think i'm good :D
12:13:43 <arch> ARRGH wait
12:13:51 <arch> it's actually 5mA, sorry, was thinking of a TI one
12:13:59 <arch> still, that should be more than enough
12:14:00 <TheDude> okay
12:14:05 <TheDude> before you put that load on there
12:14:16 <TheDude> calculate how much current it's going to pull when the divider is hottest
12:14:23 <TheDude> so the NTC resistance is lowest
12:14:40 <TheDude> also add a capacitor at the input of the ADC
12:14:45 <arch> right, at about 90C, a 10kOhm ntc's resistance is about 1kOhm
12:15:05 <TheDude> you're not going to sample the temperature too often, so it doesn't matter if there's no buffer in between
12:15:07 <arch> 4.7nF like you said earlier?
12:15:13 <TheDude> you can go larger
12:15:19 <TheDude> 22n or something
12:15:40 <TheDude> or just 100, since you'll have a bunch already in the circuit
12:15:46 <TheDude> it doesn't matter here, the frequency is low
12:15:51 <arch> so, all ADC channels except the temp sensing, use 4.7nF; use 22nF for the temp sensing ADC only; got it
12:16:27 <TheDude> shall we continue?
12:17:06 <TheDude> there's a massive issue with this circuit that the "designer" didn't even consider
12:17:21 <arch> hey, give him a break. i think he's a software dev by trade
12:17:26 <TheDude> he's imitating constant power and constant resistance in software
12:17:45 <TheDude> without knowing what it does in terms of frequency response
12:18:29 <TheDude> so it might kinda sorta work for well behaved DUTs like batteries or well regulated supplies
12:18:31 <TheDude> but that's about it
12:18:43 <TheDude> the glaring indicator of this is the input voltage divider
12:18:57 <TheDude> it has a massive 100n capacitor in there
12:19:02 <TheDude> slowing the response down considerably
12:19:28 <TheDude> so you need to be aware of this limitation
12:19:29 <arch> what if you remove it completely?
12:19:35 <arch> or would it then oscillate like mad
12:19:49 <TheDude> still not great, tbh
12:20:15 <TheDude> you need to know exactly what the sampling frequency is to be able to select the low pass filter
12:20:35 <TheDude> so you remove the higher frequency images, but still keep plenty of bandwidth
12:20:42 <TheDude> otherwise the control loops are going to oscillate
12:21:01 <TheDude> and this isn't a problem we can solve in a couple of minutes
12:21:38 <TheDude> so in order to save you some disappointment later, know that it might not work terribly well in any mode other than constant current
12:21:47 <arch> bah, i dont wanna spend $600 on a cc/cp/cr load tho
12:22:09 <TheDude> well, constant current is plenty good enough for most things
12:22:23 <TheDude> also if you're going to do battery discharge tests, it's gonna work great
12:22:50 <TheDude> approximated constant power is fine for simulating a load like a SMPS
12:22:52 <arch> i mean, this year, i have saved enough to get myself this bad boy. i haven't ordered it yet though: www.saelig.com/siglent-spectrum-analyzers/ssa3021x.htm
12:23:00 <TheDude> an*
12:23:15 <TheDude> sweet :)
12:23:36 <TheDude> okay, let's move on to things that we can solve right here, right now
12:23:41 <arch> that's the only lab equipment i can afford to get this year. was outa work for close to 9 months, so had to skimp out on a lot of projects
12:23:54 <TheDude> that sucks :/
12:24:14 <arch> on the plus side, i learned how to do copperclad etching to save money, so now im hooked on that
12:24:26 <TheDude> :)
12:24:34 <TheDude> I used to do that back in the day
12:24:42 <arch> and makes far less waste than ordering 3 to 10 copies of PCBs when i only need 1
12:24:56 <TheDude> ruined the plating on the tap in the laundry room because of it :D
12:25:37 <TheDude> the gloves had a drop of etching fluid on them when I reached for the tap, didn't notice to clean it off quickly enough
12:25:56 <arch> also btw, im not using that mosfet in the schematic. im literally gonna solder chunky TO-247 mosfets onto the heatsink using low temp bismuth solder
12:26:03 <TheDude> I hope you're not cutting the FR4 with a dremel, like I did
12:26:15 <arch> i did that when i was unwise
12:26:19 <arch> using a dremel
12:26:27 <TheDude> eeeeeh, you might want to reconsider that
12:26:30 <arch> now i use a stanley knife
12:26:37 <arch> yeah, it's bad for the lungs, i know lol
12:26:42 <TheDude> with N channel mosfets, the drain is usually on the tab
12:26:57 <arch> o you mean the mosfets
12:27:03 <TheDude> soldering it to the heatsink directly is going to make the heatsink connected to the applied voltage
12:27:25 <arch> butts. so then i need epoxy or something
12:27:36 <TheDude> no
12:27:41 <TheDude> mica insulator
12:27:48 <TheDude> and a small dab of thermal paste
12:27:59 <TheDude> on both sides of the insulator
12:28:17 <TheDude> the thermal resistance is not that big
12:28:44 <TheDude> speaking of the dremel thing
12:29:01 <TheDude> I would literally make a ninja headmask out of an old t-shirt
12:29:25 <TheDude> and leave just a hole for the eyes to slide in some safety glasses
12:29:39 <TheDude> because the dremel would fill the entire room with fine dust
12:30:04 <TheDude> glass fiber and epoxy dust :/
12:30:39 <TheDude> table-mounted shears would have been a good idea, but I was a dumb teenager back then
12:31:00 <TheDude> back to the circuit, shall we?
12:31:19 <arch> this is basically a filler project for me while im waiting for my custom TV motherboard pcb project. this is what the main PCB looks like, etched DIY: https://imgur.com/a/aLzARr1
12:31:22 <TheDude> the filtering on the rotary encoder is just silly
12:32:05 <TheDude> whoa, you draw the boards on copper clad by hand?
12:32:21 <arch> no, i use kicad
12:32:56 <TheDude> the rectangular only lines with large copper pads were done in kicad?
12:33:27 <arch> yes, it's a pain in the ass, but it's possible. i use the copper pour tool and route around
12:33:39 <arch> wish they had an addon for DIY copperclad etchers
12:34:38 <arch> if you look closely, you can see i used resistor lead clippings for the fuse. i didn't have any 0805 2A fuses on hand. very unsafe :D
12:35:01 <TheDude> haha
12:35:17 <TheDude> I think a resistor lead is going to be able to pass significantly more than 2A, though :)
12:35:28 <arch> why do you say the filtering is excessive on the encoder? maybe he doesn't use software debouncing
12:35:40 <TheDude> a single strand from a fine-stranded wire would probably be more than enough
12:36:00 <TheDude> it's going to make the encoder unresponsive trash
12:36:19 <TheDude> you don't need any filtering, really
12:36:24 <TheDude> but a little bit is okay
12:36:30 <TheDude> what is done here is just shit, though
12:36:52 <arch> the way i designed that board is all power traces are far away from any signal or low current traces. even if the thing shorted out, the PSU would shut off
12:37:37 <TheDude> okay
12:37:40 <TheDude> back to the encoder
12:37:44 <arch> yessir
12:37:46 <TheDude> you have a quadrature output signal
12:37:52 <TheDude> you need to use that
12:38:08 <TheDude> you don't use edge interrupts on those, that would just be silly
12:38:23 <TheDude> sample the inputs with a constant polling rate
12:38:37 <TheDude> and use a state machine to observe the rotations
12:39:41 * electrohead offers guiness
12:39:49 <arch> that is beyond my capabilities to program it. i mean, i can slap on code and edit code, but not exactly write code
12:40:40 <TheDude> I know I have code written for this exact thing somewhere
12:40:44 <arch> let me see what the Prusa does. it uses a rotary encoder
12:40:57 <arch> Prusa 3d printer. i have one. lemme see its schematic rq
12:41:10 <TheDude> I'll need to find it, though
12:42:24 <TheDude> 10k pullups are fine
12:42:39 <TheDude> then just 1k resistors between the encoder pins and controller input
12:42:54 <TheDude> and maybe 4.7n directly on the controller pins
12:43:01 <TheDude> it's going to be just fine
12:44:55 <TheDude> moving on
12:45:07 <arch> https://www.bourns.com/docs/Product-Datasheets/PEC12R.pdf page 2
12:45:13 <arch> bottom right corner
12:45:41 <TheDude> I'd add a resistor above the trimmer pot for the LCD contrast adjustment
12:45:42 <arch> 10nF, boom
12:45:59 <arch> yep, did that before
12:46:09 <arch> i built a controleo2 on copperclad
12:46:12 <TheDude> you're already going to be using 4.7n, that's why I suggested that
12:46:12 <arch> fun times...
12:46:33 <TheDude> but certainly don't go for 100n, like the guy did
12:46:44 <arch> right
12:46:49 <TheDude> alright
12:46:51 <TheDude> last thing
12:46:54 <TheDude> the fan control
12:47:07 <TheDude> that arrangement is very weird
12:47:25 <arch> im not gonna use that
12:47:38 <TheDude> okay, perfect then
12:47:44 <arch> im going to use a PWM signal to drive a 4-pin PWM fan. the signal will be from the arduino, and will ramp up or down depending on temp
12:48:04 <TheDude> alright, sounds reasonable
12:48:09 <TheDude> one thing I'd recommend
12:48:16 <TheDude> when you start the fan from a stand still
12:48:25 <TheDude> and you apply a low PWM value
12:48:40 <TheDude> give it a higher value for like a second before you go to the final PWM value
12:48:52 <TheDude> because when the fan gets older and grime accumulates
12:48:59 <TheDude> it's going to need more starting torque to get moving
12:49:00 <arch> right, i mean, the PWM fan will be on at all times really, but at very low duty cycle, maybe 20%
12:49:24 <arch> Noctua PWM specifications say they are good from 20% min duty and up
12:49:42 <TheDude> yes, they can run at 20%
12:49:51 <TheDude> but can they start without hassle at 20%?
12:50:12 <TheDude> have you ever heard a server start up?
12:50:16 <arch> no :D you are correct, so apply full throttle PWM for a second or two
12:50:23 <TheDude> not even full throttle
12:50:32 <TheDude> you can give it maybe 40%
12:50:38 <TheDude> if you're using a 4-pin fan
12:50:43 <TheDude> you can observe the RPM
12:50:50 <arch> and i'll also detect the rpm using the tachometer
12:50:55 <TheDude> and lower the value as soon as you see it jump up sufficiently
12:51:00 <arch> right
12:51:52 <arch> cool, i believe this should work reasonably. thank ya kindly for the assistance :3
12:52:22 <TheDude> anytime :)
12:54:23 <arch> oh wait a second, do you think i should add in a fuse at the input of the load? maybe 10A, since this one's rated 8A max
12:55:22 <TheDude> it wouldn't be a bad idea, really
12:56:24 <arch> cuz if the mosfet dies, i dont want things to go up in smoke...except the fuse of course
12:56:54 <TheDude> uhm... sorry to break it to you
12:57:20 <TheDude> but if the fet dies, your things *ARE* going to go up in smoke
12:57:39 <TheDude> a fuse is not going to save silicon
12:57:56 <TheDude> but it will prevent an unruly DUT from burning down something
12:58:10 <TheDude> say a big fat battery
12:58:17 <arch> right, but when it goes short, 10A isnt enough to make a mosfet catch fire
12:58:23 <TheDude> you don't want to leave a permanent short on there, if the fet blows through
12:58:32 <arch> correct, thats why the fuse
12:58:38 <TheDude> its plenty to make it catch fire
12:58:52 <TheDude> but the duration also has a large importance there
12:58:57 <arch> right
12:58:59 <TheDude> which is where the fuse steps in :D
12:59:06 <arch> oh a wise guy eh?
12:59:10 * arch pokes TheDude in the eyes
12:59:13 <TheDude> :D
12:59:15 <arch> nyuk nyuk nyuk
12:59:31 <TheDude> there's this misconception in electronics that fuses actually save shit
12:59:33 <TheDude> they don't
12:59:40 <TheDude> they just save your house from burning down
12:59:41 * electrohead short circuits arch
12:59:51 <arch> so they DO save shit
12:59:52 <TheDude> fuses are slow as shit
13:00:07 <TheDude> putting 15A through a 10A fuse is going to take a fair bit of time to blow through
13:00:17 <electrohead> that's what she said.
13:00:19 <arch> https://i.kym-cdn.com/entries/icons/original/000/028/596/dsmGaKWMeHXe9QuJtq_ys30PNfTGnMsRuHuo_MUzGCg.jpg
13:00:20 <TheDude> now 80A through there is going to make it blow a fair bit quicker
13:00:23 <electrohead> sorry, beer kicked in :P
13:00:42 * arch hands electrohead some rum
13:00:48 <electrohead> oh?
13:00:50 <electrohead> what kind?
13:00:59 <arch> colombian
13:01:02 <arch> so fragrant
13:01:05 <TheDude> okay, I'll be heading to bed now
13:01:07 <electrohead> ooo, yum
13:01:10 <TheDude> it's liek 3 in the morning now -.-
13:01:14 <TheDude> like*
13:01:20 * electrohead waves at TheDude
13:01:22 <arch> yeah, nighty night
13:01:44 <electrohead> TheDude: how are the adventures in linux coming along?
13:01:49 <TheDude> I'd love to help you further with your project, should you have some questions
13:01:57 <TheDude> electrohead, slowly making progress :)
13:02:00 <arch> i find it funny that TheDude knows all this complex shit, but struggles with linux :D
13:02:00 <electrohead> :D
13:02:17 <TheDude> I'm now working on securing my remote desktop connection
13:02:20 <electrohead> lol xD
13:02:32 <TheDude> I set up a dynamic DNS today \o/ :D
13:02:36 <electrohead> hey, everyone starts somewhere with things :p
13:02:45 <electrohead> \o/
13:02:49 <arch> damn straight
13:03:01 <electrohead> I outgrew DDNS a long time ago
13:03:09 <electrohead> still have it set up though, just in case
13:03:21 <arch> are you guys self hosters? i used to do that back in college
13:03:48 <electrohead> but, I have a static spoofed mac address set on my firewall/router, and everything has a battery backup, therefore my IP hasn't changed in a loooong time
13:04:04 <TheDude> I only started this because I'm visiting the parents for a slightly longer period of time
13:04:07 <electrohead> arch: hell yes I am
13:04:16 <TheDude> and I want access to my desktop computer
13:04:34 <TheDude> so I got the bright idea to open a port in the firewall to allow remote desktop connections
13:04:43 <TheDude> but now I'm improving on that :D
13:04:45 <electrohead> TheDude: did you change the default port?
13:04:50 <TheDude> yes
13:04:51 <arch> do you want russian hackers? that's how you get russian hackers
13:04:58 <TheDude> yes, I'm aware of that
13:05:01 <electrohead> ok good *wipes sweat off of forehead*
13:05:10 <electrohead> plus more >.>
13:05:11 <TheDude> I'm in the process of setting up SSH
13:05:19 <TheDude> and through that I'm going to connect to remote desktop
13:05:19 <arch> electrohead, changing port wont help with portscanners tho right?
13:05:27 <TheDude> and close the direct port to remote desktop from the world
13:05:30 <electrohead> not really, especially with nmap scripts, etc
13:05:58 <electrohead> but, with changing the default port, all scanners looking for RDP normally just look for the default port number
13:05:59 <TheDude> I can confirm that Ampera and jspiros on the other channel were able to find my open port today .d
13:06:17 <arch> lol. now you have been hax0rzed
13:06:31 <electrohead> I'll promise not to mess with you.
13:06:38 <Nothing\> hey hey hey
13:06:39 <electrohead> :P
13:06:45 <TheDude> so yeah, I'm going to try and find some solution for this before someone reams my computer a new asshole
13:06:52 <Nothing\> how's yall doin'?
13:06:56 * arch pushes Nothing\ in a corner
13:07:01 <arch> shoo shoo
13:07:03 <arch> jk :D
13:07:06 <TheDude> well, I'm on my way out
13:07:08 * Nothing\ gets some wood
13:07:13 <electrohead> TheDude: a tunnel over SSH, at a minimum, will help out a fuck ton
13:07:19 <TheDude> I've been awkwardly standing by the door and holding the handle for some time now
13:07:25 <electrohead> lol
13:07:28 <arch> poor Nothing\... everyone always leaves when he gets in the channel =(
13:07:32 <Nothing\> TheDude, story of my life
13:07:36 <TheDude> electrohead, yes, that's what they suggested in the other channel
13:07:42 <Nothing\> yeah really arch haha
13:07:43 <TheDude> gonna do that
13:07:55 <TheDude> the other suggestion was using a VPN
13:08:08 <TheDude> but that's going to cost
13:08:08 <arch> set up openvpn. it's not so difficult
13:08:15 <electrohead> alright man, get some sleep, and once you get going with linux, and all the security stuff, hit me up, I'll help you out :)
13:08:21 <electrohead> wireguard!
13:08:33 <electrohead> wireguard is very nice, and nice on resources
13:08:40 <TheDude> neat
13:08:48 <TheDude> okay, see you, bye
13:08:51 <electrohead> o/
13:08:54 Quit: TheDude ([email protected]) Quit: Leaving
13:09:02 * electrohead pokes Nothing\ with an empty guiness can
13:09:19 <electrohead> thedude is a cool dude :p
13:09:29 <arch> interesting, i was vaguely familiar with wireguard, but i didn't know it JUST made it into the kernel in march
13:09:35 <electrohead> correction - everyone in here that are regulars, are cool :)
13:09:46 * Nothing\ peeps
13:09:49 <electrohead> yeah, that was recently
13:10:04 <electrohead> I still need to get a proper wireguard setup going
13:10:19 <electrohead> but for now, I use ssh tunnels for everything, with IP whitelist/blacklisting
13:16:32 <arch> later folks
13:16:45 Quit: arch ([email protected]) Quit: Leaving
13:26:06 * electrohead pokes Nothing\ with an empty guiness can again
13:26:16 <electrohead> that one went down really fast, holy shit
13:27:25 * T3sl4 pokes electrohead with a guiness book
13:27:50 * Nothing\ poops
13:27:56 <Nothing\> err
13:28:01 <Nothing\> peeps
13:28:07 <Nothing\> lol i knew that was gonna happen
13:28:30 <Nothing\> i use dvorak so all of my vowels are in my home row as follows: aoeui
13:28:43 <Nothing\> so o is right next to e lol
13:31:56 <electrohead> ok
13:31:59 <electrohead> lmao
13:32:16 <electrohead> either way, you still talk about pooping quite some in this channel :P
13:32:21 <electrohead> fucking goof, lol
13:34:13 <Nothing\> electrohead, i talk about whatever's happen atm
13:34:21 <Nothing\> and with me it's usually 1 of 3 things
13:34:26 <Nothing\> 4, sorry
13:34:26 <electrohead> :p
13:34:42 <Nothing\> gaming, youtube, pooping and electronics of course
13:34:44 <electrohead> I'm not calling you a fucking goof in a bad way, by the way
13:34:51 <Nothing\> no i know
13:34:54 <electrohead> you're just a goof, hahaha
13:35:31 <Nothing\> electrohead, i never understood how goof could be such a severe insult anyways
13:35:50 <Nothing\> i was thinking though
13:43:49 * electrohead thinks with you
13:43:57 <electrohead> nothing is happening
13:44:00 <electrohead> lol
13:55:35 Quit: coppice_ ([email protected]) Quit: Konversation terminated!
15:01:10 * electrohead wonders around hopelessly
15:29:33 * T3sl4 is baking cookies
15:30:54 <steve30> did someone say cookies? :p
15:34:28 <T3sl4> i'm give you one, but they're still rather squishy and/or hot :P
15:35:27 * steve30 nibbles on the cookies
15:36:30 <T3sl4> er, i'd*
15:47:58 <T3sl4> first batch is out :3
15:48:30 <steve30> :)
15:50:20 * steve30 curls up next to the cookies
15:54:43 * electrohead throws cookies at T3sl4 and steve30
15:55:02 <T3sl4> go toss your own cookies
15:55:23 <electrohead> :p
15:56:55 <Nothing\> that was weird
15:58:01 <Nothing\> i just sent a message to an old friend of mine cuz he invited me to his placefor a pokernight (his house is in the hot zone and all social gatherings are illegal) so I told him we'd have to do it another time or whatever
15:58:34 <Nothing\> but thenwhen i sent the message, there was more added to it that i sure didn't type
15:58:58 <Nothing\> saying i hoped his family was doing alright during all of this craziness and wishing them a new year
15:59:48 <steve30> I had someone round for an illegal visit yesterday :)
16:04:08 <Nothing\> oooh meringue cookies
16:04:12 <Nothing\> i'm totally devouring these
16:20:55 <steve30> ooh, we're now up to 30000 coronavirus cases per day here
16:24:39 <T3sl4> oh cool, going for herd immunity i see
16:32:02 * steve30 pets his stash of coronaviruses :)
17:03:32 <T3sl4> your gramma appreciates it
17:09:55 <steve30> I think I'll do a coffee
17:52:17 Join: Kuschelpony ([email protected]) to #EEVblog
17:52:22 * Halcyon licks T3sl4
17:52:35 * T3sl4 stuffs his cookie in Halcyon's face
17:52:41 <Halcyon> Oooh sprinkles
17:52:53 <T3sl4> they're pecan and toffee-chunks :)
17:53:00 <Halcyon> Oh delicious
17:53:57 <Halcyon> I bought a second solar array and batteries today
17:53:57 <Halcyon> :D
17:54:26 <steve30> nice
17:54:32 <steve30> to go on the roof?
17:54:38 <Halcyon> Yes
17:54:55 <Halcyon> I have a 5kW system now, this will bring it to 10 with a 5.8 kWh battery system
17:55:30 <Halcyon> The feed-in-tariff is also excellent, it beats the shit 9.5c/kWh I'm on now
17:55:34 <steve30> That makes my 2.7kWh system look small
17:56:03 <Halcyon> We know there is nothing small about you Steve ;-)
17:57:36 <steve30> :p
18:01:03 <T3sl4> delicious feed inta riff
18:01:14 <steve30> Halcyon, what are you doing for Christmas dinner?
18:04:13 <Halcyon> We had our christmas a few weekends ago, just how everyone's schedules lined up
18:04:19 <Halcyon> Going to my parents tomorrow for lunch
18:04:30 <Halcyon> Otherwise tonight, it's wine and burger and chips with Mark :P
18:07:08 <steve30> https://www.flickr.com/photos/sumfight/5735262950/in/dateposted/
18:08:01 <T3sl4> mmm, burg
18:20:50 * steve30 cuddles Halcyon
18:22:03 <Halcyon> LD
18:22:06 <Halcyon> :D
18:22:18 <Halcyon> Also, stupid cats
18:26:08 * steve30 continues to wonder what Halcyon got him for christmas
18:29:06 <Halcyon> :P
18:30:13 <Halcyon> How about an Aussie millennial ? https://www.youtube.com/watch?v=EgJI5Pp1Wvw
18:31:49 <steve30> He'll do :)
18:37:47 Quit: Kuschelpony ([email protected]) Connection closed
18:43:41 Join: Watcher ([email protected]) to #EEVblog
18:57:58 <Halcyon> He used to be a model
18:58:35 <Halcyon> https://www.youtube.com/watch?v=QouJiyHnsRM
19:01:58 <steve30> I could make out with him
19:09:39 <steve30> so, can I trust that he'll be waiting under my christmas tree tomorrow?
19:16:43 <Halcyon> :P
19:19:46 <steve30> although he does sound straight in that video
19:19:49 <Halcyon> He is
19:20:55 <Halcyon> There is an Aussie queen for you: https://www.youtube.com/watch?v=7FE9rfiwaGA
19:21:25 <rust_collector> maybe you can do some steves conversion therapy. look at it as a challenge
19:42:16 <steve30> he sounds gay
20:39:09 <Halcyon> Funny that :P
22:02:49 Quit: Watcher ([email protected]) Quit: i'am out
22:27:03 <hsn> me therapy
22:27:24 <hsn> i want thera pee
22:31:37 * Ampera hugs Halcyon
22:34:49 * hsn hugs hugged halcyon by hugging Ampera
22:34:58 * Ampera hugs hsn
22:35:00 <Ampera> how are you doing
22:35:16 <hsn> im doing bad .. thanks god.. and you ?
22:35:36 <Ampera> annoyed, I'm sending a package with christmas presents to my family in germany and the stupid EU customs gremlins want more money
22:35:56 <hsn> Ampera, they send half of it to Ysjoelfir
22:36:01 <hsn> so take it back from him
22:36:12 <hsn> :P
22:36:16 <Ampera> I asked the customer support for my shipper and they said it's something based on the value of what I declared, which is dumb
22:36:19 Join: Kuschelpony ([email protected]) to #EEVblog
22:36:37 <Ampera> I declared the value at 50 bucks, I'd have to import something worth hundreds to have to pay import duties on it here
22:36:55 <hsn> thats why u should always put like chineese "worthless gift" in their packages
22:37:25 <Ampera> then they just send the package right back for lying on it
22:37:56 <hsn> thats why .. dont send it brand new .. put "used" item
22:38:08 <hsn> and it worth much less now because u used it
22:38:26 <Ampera> yes, used chocolate bars and candy
22:38:28 <Ampera> cotcha
22:38:37 <hsn> yes exactly
22:38:42 <hsn> licked and repackaged
22:51:36 * electrohead repackages Ampera
22:51:54 * Ampera returns electrohead to sender
23:12:02 <electrohead> lol, good morning
23:24:47 <hsn> gm electrohead
23:25:01 <electrohead> hey hsn
23:26:27 <hsn> o/
23:26:33 <hsn> merry xtmas to u
23:34:26 <Halcyon> Hey Ampera, love you
23:43:57 Quit: Nothing\ ([email protected]) Ping timeout: 121 seconds
23:49:21 * electrohead pokes Halcyon
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