Even worse, the precision band is brown against the blue and often symmetrically spaced, so it can be impossible to tell a 120 ohm resistor from a 10k ohm resistor by markings alone, and requires good light to even distinguish brown from red, black, and purple.

Keep all you different values separate from eachother and label the boxes or bags. When in doubt, just measure it. When dropping a box with 50 different values on the floor and they get mixed up; throw them away and buy new ones.

@@Ni5ei That hasn't been worth it for me, mostly because I try to keep many more values on hand (somewhere between E24 and E96, from 0.01 to 10M), so I have fewer of any at a time. I test a resistor on any ambiguous tape segments and mark just past the precision band with a black marker to make them less ambiguous. I try to bin them by decade, which at least makes searching the labeled remnant tapes free from mixing up K and R.

Agree

I always measure a resistor before soldering it. Measure twice cut once. 😉

+1.

Yes. When the part is installed on the PCB, I touch the part with my finger and then press the finger to my lip. The forehead also works well. I also use the back of my hand over a circuit board where I suspect heating. I call it my low resolution thermal camera.

that's because they use chicken shit as the resistance element and it dries out.

Wow, that is good to be aware of. Thanks!

Frankly, I'd never consider getting components from Amazon. If I need components, I'll order them from Digikey and call it a day.

@@centrospherecom What are you, a high school student...a freshman??? From what you wrote, it shows that you have no clue about the real world. You're outside walking, a light bulb goes off and you have an idea for a new project. You go to your hobby desk, pull out a bread board and start experimenting. I and about everyone I know in this industry, is NOT going to use SMD resistors when you are playing around with an idea. What you are saying is; Why should we even have bread boards. Each time you have an idea, we should get right into KiCAD, Fusion360, etc., draw out the PCB, pour out some FeCL and some NAOH and create a new PCB! COME ON! Give me a break! Use some common sense. No way am I going to use SMD resistors on a bread board. You need some real world experience!

@@mtnwildernessfamily -- But technically, you could. It still would not be 100% the same. I mean, build some SMD jigs. Of course, I've never done this. And yeah, I'm not going to draw a new board each time I want to play around.

That's interesting to learn. I didn't know that.

I didnt know that. Im glad I dont buy from Amazon then. What a terrible company. But this has been a common problem with warehouses and suppliers for the manufacturing industry for years. This kind of fakery has even caused plane crashes in the distant past. The only winners are the suppliers who source parts from outside to fulfill demand when thier own supplies run out and the warehouses themselves.

I recently bought ten 74LS157's from Amazon themselves that said was from "Major Brands", I've had good experience in the past getting parts from them that had that title. But this time with another order of 74LS21's I received knockoff Texas Instruments LS157's with distorted logo that are either A: Relabeled HC157's or B: fakes that may or may not work. Haven't tested them yet. I'll stick with Ebay or move to Digikey/Mouser.

Bojack Horseman makes resistors?

I wonder if iron core would cause more inductance? I would think so, so not a good idea for high frequency applications.

Good point, especially as once you get over a few ohms the resistance of the leads is a miniscule fraction of the total resistance.

@@franzliszt3195 No; The magnetic field is 'radial', it is not on same axis as the conductor. (essentially no effect).

You haven't had the pleasure of reading glass zener diodes; they print the 1N number on two lines around the along the axis. (Or Amp or Molex connector designations!)

@ElPasoTubeAmps you'll have likely heard of Welwyn W20 series. Iron leads to prevent heat flowing to the PCB. Intended to run hot the vitreous enamel fluidizes to prevent resistance underneath oxidizing.

Tbh 5% is good enough most of the time, assuming you're mostly going digital with led current limiting or logic level pull-ups. I had a rogue (X10 error) one in a batch once, so now always sanity check the values with a meter before breadboarding/soldering.

Maybe videos like this will make more people aware. I certainly never knew, though I always wanted to know.

Yep, they've been selling a wide assortment of components for a while now. I imagine they've got sourcing more "dialed-in" compared to the other brands at this point.

The wire lead material is important because it helps dissipate heat from the body, which mean the iron lead resistors will handle less power

@@brainndamage a quarter watt is a quarter watt, it should dissipate the heat without consideration of the leads themselves, which could be of pretty much any length.

The laugh is, years ago when I started out in electronics, 20% tolerance wasn't uncommon, 1% was wire wound and eventually, metal film. Of course, the circuits are far more reliable now, due to much better tolerance and materials.

@@spvillano true that or course if it's dissipating 1/4W, it will do so until it fails. The difference in thermal resistance to air is what will determine the body temperature and thus its limit of dissipation for long life.

@spvillano except resistors which require a minimum lead length and must be spaced away from PCB, such as Welwyn W20 series. Has iron wires to prevent heat conducting back to PCB.

Hopefully you then conformal coat it in some way as it'll oxidise and change over time.

Totally depends on the circuit it is in; in some cases, increased resistance in a certain part could increase circuit dissipation... In many cases, it will only cause improper operation or function. Not all resistors are in a place where they control power consumption or bias... A general guideline of always choosing resistors with PTC is not going to be helpful.

There's value with temperature, but there's also noise. Cheap and seconds are going to be noisier. Not too big a deal in a logic circuit, but anything with significant gain and that noise could overwhelm signal.

remember the story of how Sony got it's name. Don't try to make up brand names in a language that isn't your own.

Probably some crud on the leads themselves from when they were made or packaged.

Moisture from your fingers can also cause a voltage between different metals of your probes and the leads. Most DVMs utilize very low voltages to measure resistance, and a few millivolts can throw off the reading. Interesting thing to try, put the meter on MILLIVOLTS and hold it the same way as you did when measuring resistance, and see if ANY millivolts appear on the meter...

You're not an electrical engineer, and you are blind as well. Pause the video at 3:20 and count the wires in the jig. Standard KZfaq, people pretending to be smart by writing long technical comments.

@@j.f.christ8421 dear fried, at 3:20 it's clearly shown that your setup is wrong. Let me explain again: The high impedance measuring wires are attached to the jig. This can be seen clearly. This wires are measuring the voltage at the jig. But there will be an additional voltage drop from the jig to the lead of the resistor. This will result in a chain of serial resistors that are measured by the high impedance measuring loop: connection resistance jig to resistor left side PLUS resistor PLUS connection resistance jig to resistor left side. The result of this R=U/I will not be the resistor value but the resistor value PLUS two unspecified connections. Some people even do not take the effort for rethinking where they had been wrong, even they start bashing on those who explain it to them.

Sorry, a typo error. It must be: connection resistance jig to resistor left side PLUS resistor PLUS connection resistance jig to resistor right side

If you want to go it right, your jig must have 4 contact points to the resistor wires: Two outer points for driving the current and two inner points for sensing the voltage at the resistor. Just google: "4 point resistance measurement". You will see that a jig with 4 contact points is required.

@@GeorgeHelmut Ok, and by exactly how much is this affecting the measurement? You write like someone who has read the theory and never done the practical.

48V phantom power is an example of such "good" design. 6.81k must be matched 0.1% or better. Also needs some esoteric short circuit and protection circuit. 90% of manufacturers don`t bother implementing. So there are, i think, one thousand blowed mic-preamps with phantom power each day in all world.

@@tevatronxenotron1977 That's about the only single one part of a studio mixing console that needs matched value pair of resistors. As long as they're matched they can be any other value roughly near 68K. Even then in practical use in a studio if one channel is "hummier" than others they just use that channel for something else. If they do insist on repairing it they'll send the Tea Boy or Tape Operator off to get "68.1K" so he doesn't come back with the ordinary 68K they try and sell him that's the exact same one 68K 20% fitted in McCartney's / Hendrix / Clapton guitar amp input socket. I've just looked at schematic for a high quality stereo hifi amplifier and of the 100 or so resistors not a single one needed to be 1%

@@tevatronxenotron1977 Oh and about protection, accuracy of phantom power resistors isn't the cause of blowing up mics, but having the PP switch left on in combination with a worn out connector pins that don't connect simultaneously on long runs at concerts can blow up the wrong kind of mic. And on a film set with sound especially they blow up recording studio mics but I think that's because film sound people only use their own special type of gear only they know how to use so it keeps them in a job.

@@jagmarc There is PDF that observes that anecdotal design of classic phantom power circuits. Blowups of preamps can be prevented. "The 48 Volt Phantom Menace" "we encountered persistent reports from users of field failures of existing devices. Anecdotal evidence suggested that these failures were correlated with accidental connections between line-level outputs and microphone inputs, particularly if 48-volt phantom power was activated on the microphone channel." "In subsequent sections, more robust protection schemes are analyzed and the accompanying engineering tradeoffs are discussed. Additionally, changes to typical circuit design practice that will mitigate the problem are shown."

@@tevatronxenotron1977 Many studios made up their own DI boxes that were 48 V phantom powered. There was a 'darwinistic' thing going on with mics. Guitarists were very nervous about letting anyone directly connect anything directly to their amps and keyboardists..... Bass players happily plug their instrument direct in to the console but without their amp. The only reason it's 48 V anyway is because that just happened to be the voltage of standard telephone system batteries that a TV studio in Finland were using and thanks to that we're stuck with it. 12 V would had worked just as well. Mics with exotic batteries inside went out of fashion. Film sound people meanwhile their 'betamax' system blow up incompatible mics

They should have lead length as an option.

Because they are designed to fit in machines that dispense them ready trimmed and bent, and inserts them into the PCB ready for soldering. Shorten the legs, and they stop fitting in the machines.

The simple fact of the matter is that leaded resistors for through-hole boards are obsolescent except for more specialized types.

Is Lum from Urusei Yatsura involved with the testing process?

@@haloslayer255 Sorry, but I do not know what you are talking about.

@franzliszt3195 Urusei Yatsura is an anime I recently started watching. One of the main characters, Lum, calls Ataru, "Darling." Every time Ataru cheats on Lum, he gets shocked. For more info kzfaq.info/get/bejne/bM2ao7hltNC5lHU.html

A 1kΩ resistor is NOT going to overheat from current in too small leads, they would have to be tens of ohms to even add any heat. (they'd have to be hair size). Assuming you're talking about 1/4W or such. You have other issues going on there. Wrong actual value, bad lead bond, undersized design (safety factor), circuit malfunction... {thermal conduction could be argued, but it would have to be running close to it's limits already for this to be a factor; again, design or malfunction).

Select-on-test is sort of OK for hobby work, but it is VERY expensive to do in even moderate commercial production. 5% tolerance leaded resistors are almost all carbon film types these days, except for "power" types. 1% tolerance small resistors are typically metal film. Metal film has much better temperature coefficient of resistance than carbon film and typically substantially less excess noise (that is, noise other than Johnson noise)

You can't make that kind of generalization. Many of the circuits I have designed required resistors of no worse than ±1% tolerance and I've used many of 0.1% or better tolerance with temperature coefficient of resistance down to ±10 ppm/°C or better. In precision analog circuitry the resistors are critical components in circuit performance. In lots of digital stuff you can be incredibly sloppy. I'd often go through the values I used in non-critical circuits to reduce the variety of values required for a board. i might, for example, change what I had originally specified as 4700 ohm resistors to 7500 ohms because I needed a few of the 7.5K for part of the circuit and nothing actually required 4.7K with any accuracy. Reducing the variety of parts reduces inventory and other costs. High-volume consumer products, which I've never done, are another matter. There people carefully consider price differences of a fraction of a cent per component. When you buy a million resistors, a tenth of a cent each is a thousand dollars. In days gone by lots of analog circuitry had gobs of trimmer resistors, out of necessity. I regard every trimmer in a circuit as a defeat unless there is a really compelling reason to have one.

Completely true! I built hundreds of electronic projects with 5 % and 10 % resistors. The tests in this video suggest that you need precision resistors to get a circuit working. That idea is (sorry to say) wrong when you know how to design electronic circuits. Also that there is a "rated voltage" for a resistor is a misunderstanding. For measurement purposes you could need precision resistors with a low temperature coefficient. And even then: it depends on the measurement circuit and you can do precision measurements with 5 % resistors. 1 august 2023.

@@radiofun232 I see absolutely nothing in the video that suggests that you need precision resistors to get a circuit working. It is simply looking at some characteristics of some reasonably readily available 1% parts (1% is generally regarded as only "semi-precision" when it comes to resistors). Yes, you can make most circuits work with 5% or 10% tolerance parts. Many circuits will work perfectly well with such tolerance. Others will work dismally badly except in the occasional case where either tolerance is much better than nominal or two or more parts just happen to be well matched, even if the value is quite different from nominal. 5%, 1%, 0.1% and better resistors all exist in the marketplace. 5% parts exist because they are adequate for most things. The better parts exist because they are necessary for other things. If you go into trying to make a precision measurement circuit with the idea that 5% resistors in the sginal path are acceptable you are most likely doomed to failure. For example, the 12 bit ADC on your microcontroller will still resolve to 1 part in 4000 with 5% resistors in the signal path, but the actual accuracy could easily be reduced to 5 or 6 bits. That *may* be OK or it may be grossly unacceptable. Only a fool would try to make a differential amplifier to recover a 1 mV signal from 1000 mV of common mode with 5% parts, even if the final gain accuracy required were only ±10%. 5% are likely to be perfectly acceptable for setting up the VCO of a PLL in a circuit requiring 0.01% accuracy or in setting the bias for a crystal oscillator circuit of similar precision. Ignoring the voltage rating of resistors is a bad idea for anything that needs to be reliable. Mostly the rating is just dielectric strength and tends to be conservative, but it shouldn't be ignored (do it for one-off circuits you'll use at home if you like and are sure that a failed circuit won't start a fire). In the vast majority of cases these days the voltage rating will be far in excess of what is actually needed, but not always. I've used two resistors in series to get adequate voltage rating in places like the input circuitry of a switched mode power supply. Don't expect safety agency approval if you get sloppy with stuff like that.

@@d614gakadoug9 Thanks for your comment, much appreciated. When you talk about digital electronics (ADC's) you are right about the use of precision resistors, say voltage ladders etc. I have to say my focus is completely on analog circuits. The voltage rating is in my opinion not relevant, the dissipation is a serious issue (and another issue). The demo in the video is in fact focused on the dissipation.

I looked closely at the jig too and thought a little questionable, but easily to verify if the jig is accurate enough.

@@franzliszt3195 At least, the 4-wire measurement is obsolete. Maybe the expensive DMM is just decoration.

@@MuellerNick what do you mean obsolete? What replaced it?!!!!

@@franzliszt3195 The two wire connection of the measurement equippment to the DUT.

@@MuellerNick what????

Pretty sure the voice is AI translated. Meh, at least it is done well.

It's a translation, very obvious...

@@perlguiman I bothered me a first, but the quality of the information makes it very worthwhile.

The KZfaqr is speaking Japanese, the voice is English… so yeah, no lip-sync. It’s impossible.