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Seconding The Art of Electronics. Also welcome back, you're getting back into electronics during a historically bad global chip shortage  ATTiny's are fine but these days you can get knockoff arduino nanos for less than $5 a pop and they're not much bigger and already have all the support circuitry and a USB connection onboard: https://www.amazon.com/AiTrip-Arduino-ATmega328P-Controller-Module/dp/B09DKHWSY9/ Once you get to the point where you actually need to use the chip by itself I'd generally recommend just learning how to program them without Arduino (it's not actually that hard) and then you can use whatever chip best matches your application (or nowadays, whatever chip you can actually get in stock  ) rather than being restricted to the ones people have gotten Arduino stuff running on.
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Dec 24, 2021 18:59
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I asked this in IYG but figured the electrically minded people ITT might have a better understanding. I just got a bundle of home theater equipment for nearly free. One thing I got was a Panamax M5100-PM power conditioner. I know that power conditioners are hokey in terms of improving sound quality, but I was thinking it might be stronger than a surge protector in terms of protecting my equipment. However, the unit is at least ten years old, so is it safer to stick with a newer plain old surge protector?
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Dec 27, 2021 23:16
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SkunkDuster posted:What is the context of this? I have a Weller iron that is similar to the WES51, but without the heat control. The heat settings are "off" and "hot enough to weld steel". I'm going to look at modifying it to add heat control and took your advice to get a dedicated hot air station: Upon closer inspection, it is a Weller WTCPT base with a TC201T iron that appears to have a stuck thermostat. I don't think it is repairable and a replacement iron is $100 on amazon. I'm not sure if I want to spend $100 to have a working soldering iron with no heat control. Then again, I'd rather spend $100 to have an iron that will last for the rest of my life, than spend $250 for one with a heat control that will crap out in a few years. Need to think about this one. Skunkduster fucked around with this message at 15:07 on Dec 28, 2021 |
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Dec 28, 2021 15:03
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KOTEX GOD OF BLOOD posted:I asked this in IYG but figured the electrically minded people ITT might have a better understanding. This is a tough call. If it were my gear I'd keep the power conditioner. The datasheet for it makes specific objective claims about what it does (for example how much surge energy it can dissipate, how much it attenuates RFI) so even if most peoples' reasons for using them are audiophile nonsense this device does measurable things and is a reasonable surge suppressor. I wouldn't worry too much about component aging except for maybe electrolytic capacitors, but unless it was stored sonewhere hot or made with especially bad caps, 10 years isn't usually long enough for those problems to start appearing. A caveat to this is connected equipment warranty. If you buy just about any old surge protector new they'll cover your gear up to some amount. I don't know if that sort of thing is transferable or limited but if you care it might be worth checking with Panamax to see if theirs exists and still applies to you.
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Dec 28, 2021 16:25
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KOTEX GOD OF BLOOD posted:I asked this in IYG but figured the electrically minded people ITT might have a better understanding. 'Power Conditioners' basically fall into the category of just some extra noise filters, or a full-blown AC->DC DC->AC always-on inverter. Since this isn't the latter I wouldn't put much stock in it. You'd think that a higher-end product would have better surge protection too but it's possible it's just pure garbage like a lot of audiophile stuff. Knowing nothing else about it I'd probably trust a brand new brand name surge protector strip just as much. Or even better a decent line-interactive (not an always-on) UPS. EDIT: To expound, not that surges are not real but in my entire life I'm aware of one real 'surge' event in a city I lived in where literally all the power in the entire city went out and as the grid collapsed there were surges in different neighborhoods and some had damaged electronics. Thankfully that missed me. I'm generally more worried about mechanical damage caused by repeated flickering/brownouts or unstable power as the power comes back on after an outage. A UPS pretty much solves that problem and a normal surge protector will not. I think if you have reason to suspect real surges are an issue, I'd get one of the monster 240V whole house surge protectors right at the service box and then that combined with individual surge protectors should keep you pretty safe. You're talking about a once-in-a-lifetime event where lightning or whatever hits close enough to damage stuff but not close enough to nuke your surge protectors. Rescue Toaster fucked around with this message at 17:07 on Dec 28, 2021 |
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Dec 28, 2021 16:26
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Hey Thread, just wanted to mention my sweetheart asked me what I wanted for Christmas and I gave her links to various soldering equipment, but then she went wild and got me one of those pairs of jeweler's loupe glasses, too. Anyway I tried all this stuff out for the first time last night, and managed to get some decent results. I used non-cleanup flux for the first time, as well as a fumes fan. I think I may still learn some of this stuff. The jeweler's glasses I can imagine using for some really detailed work, but they reduce my depth of field so much I'd rather stick with cheap 2.5x reading glasses and a lamp with a magnifier lens for most purposes.
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Dec 28, 2021 17:30
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Rescue Toaster posted:EDIT: To expound, not that surges are not real but in my entire life I'm aware of one real 'surge' event in a city I lived in where literally all the power in the entire city went out and as the grid collapsed there were surges in different neighborhoods and some had damaged electronics. Thankfully that missed me. I grew up at the very end of a long stretch of power line and surges were a very real thing for us, to the point where my dad would crack open power strips and add his own MOV's. If you're in the middle of a city they're probably a lot less of a big deal though yeah. e: Also this was Florida, where "once in a lifetime" lightning strikes elsewhere are basically monthly occurrences lol e2: Also also don't add your own MOV's to power strips like my dad did, when they fail they tend to rapidly heat up and real surge protectors have thermal fuses or other protection to cut them off before they ignite 
Shame Boy fucked around with this message at 19:03 on Dec 28, 2021 |
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Dec 28, 2021 18:58
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Shame Boy posted:I grew up at the very end of a long stretch of power line and surges were a very real thing for us, to the point where my dad would crack open power strips and add his own MOV's. If you're in the middle of a city they're probably a lot less of a big deal though yeah. Heh had a buddy that used to always add those. His philosophy was to add 3 in series, and nothing could fry 3 of those guys and still make it to his hardware.
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Dec 28, 2021 19:17
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I always wondered about those 'brick wall' surge protectors I saw in electronics magazines ages ago. They're still around. But I never saw independent testing on them, and I've never lived somewhere were surges are common. Supposedly they use some big inductors instead of MOVs.
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Dec 28, 2021 19:27
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petit choux posted:Heh had a buddy that used to always add those. His philosophy was to add 3 in series, and nothing could fry 3 of those guys and still make it to his hardware. Shouldn't they be in parallel?
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Dec 28, 2021 19:38
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Cojawfee posted:Shouldn't they be in parallel? I assumed it was three parallel ones "in series" cuz otherwise it just wouldn't work
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Dec 28, 2021 19:44
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Shame Boy posted:I assumed it was three parallel ones "in series" cuz otherwise it just wouldn't work Not too familiar with how he assembled it. His big idea was that any lightning borne surge was going to be so powerful it would likely arc or spark across a single one, but 3 in a row after they've blown would hopefully do it.
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Dec 28, 2021 20:03
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petit choux posted:Not too familiar with how he assembled it. His big idea was that any lightning borne surge was going to be so powerful it would likely arc or spark across a single one, but 3 in a row after they've blown would hopefully do it. I think we're talking about different things then. MOVs don't really arc, spark or blow, they become conductive above a certain voltage and shunt the surge away from the load, and then return to being nonconductive once the voltage falls again. If one were to arc or spark, that'd be good (at least from the perspective of the attached electronics) because the arc would further shunt energy away from the load. I mean you don't actually want it to arc for fire/explosion reasons but yeah.
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Dec 28, 2021 20:25
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Any component arcs, sparks, or blows when you put enough power through it Shame Boy
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Dec 28, 2021 20:28
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Shame Boy posted:I think we're talking about different things then. MOVs don't really arc, spark or blow, they become conductive above a certain voltage and shunt the surge away from the load, and then return to being nonconductive once the voltage falls again. If one were to arc or spark, that'd be good (at least from the perspective of the attached electronics) because the arc would further shunt energy away from the load. I mean you don't actually want it to arc for fire/explosion reasons but yeah. Could he be thinking of a gas discharge tube (GDT)? Those have electrodes in a gas that are designed to arc over at a specified voltage. (https://www.mouser.com/pdfdocs/bourns_gdt_white_paper.pdf) I think most MOVs are made up of tiny metal pellets that have an insulating surface oxide, they pack the pellets together and the oxide prevents conduction up to the point that the applied voltage can generate a significant tunneling current through the oxide energy barrier.
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Dec 28, 2021 21:02
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SkunkDuster posted:Upon closer inspection, it is a Weller WTCPT base with a TC201T iron that appears to have a stuck thermostat. I don't think it is repairable and a replacement iron is $100 on amazon. I'm not sure if I want to spend $100 to have a working soldering iron with no heat control.
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Dec 28, 2021 21:16
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I really like my Hakko FX-888D
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Dec 28, 2021 21:32
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Shame Boy posted:I think we're talking about different things then. MOVs don't really arc, spark or blow, they become conductive above a certain voltage and shunt the surge away from the load, and then return to being nonconductive once the voltage falls again. If one were to arc or spark, that'd be good (at least from the perspective of the attached electronics) because the arc would further shunt energy away from the load. I mean you don't actually want it to arc for fire/explosion reasons but yeah. Sorry, I don't know what I'm talking about then. When I say arc I should have just said fail. Would that make more sense? Hey, BTW, since I'm here, I've been working on this crude little project, here it is:  It's just to make it so you can use your feet to control the little synth, is all.
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Dec 28, 2021 23:05
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The Weller WES stations have been replaced by the WE1010NA. 70 watts versus 40 for the older ones, heats up to ~700F in like 30 seconds, all digital controls, and the pencil is virtually identical and uses the same old ET tips - but you can hot-swap them without any tools (with care, the knurled nut you grab is kind of small)... overall it's a pretty nice little rig, and it's only a hundred bucks. I just picked one up for the shop at work right before Christmas to replace a dying WES51 and I'm probably going to grab one for home pretty soon.
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Dec 28, 2021 23:10
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BattleMaster posted:I really like my Hakko FX-888D I have one and really do too. The one thing I wish it had was an auto shutdown because I'm really bad about forgetting to turn it off so if you've got the same tendency, be aware.
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Dec 29, 2021 03:52
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I plug it into a powerbar that also powers the bench lighting. Pretty good "possibly on" indicator imo
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Dec 29, 2021 04:00
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Foxfire_ posted:A fx-888d is about $100 and is a perfectly cromulant entry level iron that has accurate heat control and won't fall apart I will swear to my grave that the $7 Hakko CHP-170 wire cutters are every bit as good as any $50-60 wire cutters on the market, so this seems like the best option. Thanks! ante posted:I plug it into a powerbar that also powers the bench lighting. Pretty good "possibly on" indicator imo I like that idea, but I 2-3 battery chargers connected to the same power strip as the soldering iron.
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Dec 29, 2021 04:13
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Foxfire_ posted:A fx-888d is about $100 and is a perfectly cromulant entry level iron that has accurate heat control and won't fall apart I use this one and it's great for everything I do from auto stuff, to 3d printers, to small wiring for poo poo like my headtracker point model. I have a bunch of tips but 99% of the time I just leave the chisel on it.
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Dec 29, 2021 04:18
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If I have a 120VAC to 24VDC power supply inside an instrument, is there any reason the earth ground from the wall outlet and the DC ground from the power supply should NOT be electrically connected? I'm putting together a CNC controller that contains this power supply and a handful of control boards and motor drives inside a metal case. I currently have the metal case bonded to the 120V earth ground. I have the control boards mounted to the metal case via metal standoffs, and the mounting holes in these boards are connected to the ground planes on the boards, so they're effectively bonded to earth ground as well. I'm about 90% certain that this is how it's supposed to be, but I wanted one last sanity check before I power the thing on and blow up my expensive controllers.
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Dec 29, 2021 06:08
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nobody- posted:If I have a 120VAC to 24VDC power supply inside an instrument, is there any reason the earth ground from the wall outlet and the DC ground from the power supply should NOT be electrically connected? Is the power supply already doing this for you? Sounds like your mounting holes are already making the connection for you -- ground plane -> standoff -> case -> Earth, which should be fine. Important thing is if AC voltage touches the case, it is grounded so upstream OCPD trips.
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Dec 29, 2021 19:58
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movax posted:Is the power supply already doing this for you? Sounds like your mounting holes are already making the connection for you -- ground plane -> standoff -> case -> Earth, which should be fine. Important thing is if AC voltage touches the case, it is grounded so upstream OCPD trips. It took me a sec to realize you meant "over-current protection device" and not "obsessive compulsive personality disorder". I think the only time you'd really care to keep DC ground totally isolated from wall ground is if its isolated everywhere else and you're relying on that isolation for safety like in double-insulated power bricks, in which case you probably don't have a connection to wall ground available in the first place. Though even then i'm not sure connecting it to wall ground would really do anything bad. Maybe expose you to a slightly higher shock hazard if lightning strikes nearby or something?
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Dec 29, 2021 20:22
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movax posted:Is the power supply already doing this for you? Sounds like your mounting holes are already making the connection for you -- ground plane -> standoff -> case -> Earth, which should be fine. Important thing is if AC voltage touches the case, it is grounded so upstream OCPD trips. There was no continuity between the DC ground and wall ground terminals on the power supply when I probed them with my meter, which kind of surprised me. That's what brought up my original question. The way I currently have everything wired, the DC ground is connected to the wall ground by the metal standoffs I have the boards mounted on, but if there are any potential problems with this, I could always mount the boards using nylon standoffs and keep the two grounds isolated. Here's the power supply in question
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Dec 29, 2021 22:14
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If you have a metal enclosure obviously that should always be tied to earth ground. Normally I'd say go ahead and connect your circuit ground to earth ground however is convenient and try it. If you end up having particular noise problems (60/120hz hum on sensor inputs, audio lines connecting to other devices, etc...) then you might want to consider lifting the circuit ground and attaching it to earth ground at a single point or via a ground lift circuit (an RC circuit with a heavy duty diode bridge as 'backup' if the difference between earth ground and circuit ground rises above one diode drop). Some examples here, again this is only if you end up having noise problems: https://www.wiringview.co/ground-lift-circuit-diagram/
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Dec 29, 2021 22:20
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There's no "always do this" rule. Floating the electronics relative to chassis/earth or not is making some EMI/EMC decisions, there's reasons to do either depending on goal. Connecting is more common. It's not likely to destroy anything unless you're doing else weird
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Dec 29, 2021 22:31
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Yeah I guess I was talking in terms of safety specifically, there's plenty of other reasons why you'd want to do one or the other.
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Dec 29, 2021 23:34
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TacoHavoc posted:I have one and really do too. The one thing I wish it had was an auto shutdown because I'm really bad about forgetting to turn it off so if you've got the same tendency, be aware. You can get an outlet countdown timer for this for $10-$20. They plug into the wall, the soldering iron plugs into it, and it has settable 30/60/90 minute ranges before it turns off.
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Dec 30, 2021 00:32
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I have a question about power supplies. How much noise is too much on the rails? I got this one from Amazon as a cheapo, highly rated starter bench power supply: https://www.amazon.com/dp/B08DJ1FDXV But it has a TON of noise from what I can tell... Here's a pic of me running 12v through a 1k resistor and scoping it. The noise alone is over 10% of the voltage. what should I do? is it defective?
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Dec 31, 2021 19:32
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You're probably always going to get some ripple with a switching power supply but 10% seems really bad. 10% was what we were aiming for in my lab this past semester with our lovely BJTs. I should set up my power supply and see what it does.
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Dec 31, 2021 19:49
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My cheap supply is like, 20mV
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Dec 31, 2021 19:59
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This is my TackLife 0-30 5A supply. I really like it because it uses rotary switches for setting the voltage instead of a potentiometer, which means it's really easy to set the voltage I want. I think it also means that there isn't a chance of the knobs failing and sending full voltage out. It also has an output button so you can have everything hooked up, turn it on, pick my voltage and current limit and then turn the output on. I got it off amazon, but now it is no longer on there. Some guy had left a review saying "IT'S NOT UL CERTIFIED IT WILL BURN YOUR HOUSE DOWN" but it seems like no other supply is UL listed either, sooo. Here's the setup, 12V and a 1K resistor. I didn't measure this one, but I'm pretty sure it's around 990 ohms or something when I measured it before.  Here's the scope view. It seems pretty decent. 260mV for 12 V.  And here's this Eventek I bought recently. I bought it because it does 10A and I was going to do something that potentially needed 6A. It has the lovely potentiometers where you have to get the course one near the voltage you want, and then use the fine ones to get it there, but it's still really sensitive and it still seems to jump all over the place. I do like that it has the power on there though, it also has a 5V USB charging thing there, but I'm not going to be leaving this set up all the time, so that's kind of useless.  And here is the scope view. Seems pretty bad.  If you want a smooth power supply, you're going to have to step up into the $300+ range with a linear supply. But make sure it's actually linear, it seems like some companies on amazon lie about having a linear supply.
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Dec 31, 2021 20:59
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namlosh posted:I have a question about power supplies. How much noise is too much on the rails? That's 600ns/div? I'm thinking either there's an open filter capacitor and the thing's gone unstable or, more likely, there's a loose connection or long loop of wire somewhere in your setup there and you're picking up a local AM station instead of/in addition to measuring supply noise. I guess third option is it's a really fast loop and light output capacitor and you're looking at a load step transient instead of steady state behavior. Does it still look that bad at any arbitrary time if you force trigger the scope?
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Dec 31, 2021 21:08
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Stack Machine posted:or, more likely, there's a loose connection or long loop of wire somewhere in your setup there and you're picking up a local AM station instead of/in addition to measuring supply noise. That's what I was thinking too. Have you tried putting a resistor directly across the output jacks and measuring the ripple without the alligator leads involved?
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Dec 31, 2021 21:59
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Thanks so much for all of the replies. I got this as a present and was wondering if I should return it or not.Stack Machine posted:Does it still look that bad at any arbitrary time if you force trigger the scope? Understood on the Linear vs Switching. I've combed amazon looking for linear and it's tough to discern which are ACTUALLY linear. I usually have to search the comments/reviews and someone will have confirmed. Here's an updated pic with a bigger time-base and the resistor straight across the posts. 200mV/division, so it still looks like it's about 3-400mV of straight up switching noise. I'm not trying to complain about something so cheap, but this actually makes it hard to measure stuff when I'm doing experiments. Plus I don't have a lot of experience with these so I don't know what's normal, what can be corrected, and what is straight up defective. Funny enough, I did find one that's linear for $100, I think? one of the comments says it's linear and it weighs 5kg lol https://www.amazon.com/Tekpower-TP3005D-Digital-Variable-Alligator/dp/B00LG1TGSE/ namlosh fucked around with this message at 00:19 on Jan 1, 2022 |
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Jan 1, 2022 00:16
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Hard to tell but that looks like it's reading 0V average on the scope. Benchtop supplies usually have a floating two terminal output and a separate earth ground, so unless green and black are connected together already, you can try putting the resistor and the scope between red and green instead of red and black.
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Jan 1, 2022 00:30
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I don't think it's reading 0V on the scope, it just has the 12V centered on the screen since it thinks it is a DC biased sine wave.
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Jan 1, 2022 00:45
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