Do potontiometers have various resistances? - Page 1
Forum section: electronics / beginners

author: imcute
author_rank: Newbie
timestamp: January 24, 2023, 09:35:40 am
content: HELPIDONTKNOWdo autotransformers have various inductances?how do i differentiate the anode and the cathode of a resistor?someone who knows color coding pls help

author: Halcyon
author_rank: Unknown
timestamp: January 24, 2023, 10:27:38 am
content: So much to unpack here. Added to watch list.

author: pcprogrammer
author_rank: Super Contributor
timestamp: January 24, 2023, 10:34:39 am
content: Quote from: imcute on January 24, 2023, 09:35:40 amSomeone needs to go back to school, and get the terminology rightA standard resistor does not have polarity. It works the same however it is connected.Also there are websites to help determine the value of resistors, being it SMD or through hole, like this one for instance:https://www.codrey.com/tools/resistor-color-code-calculator/Just use some google foo to find the right ones.

author: bidrohini
author_rank: Regular Contributor
timestamp: January 24, 2023, 11:38:28 am
content: Potentiometers work by varying the position of a sliding contact across a uniform resistance.https://www.electrical4u.com/potentiometer/

author: Terry Bites
author_rank: Super Contributor
timestamp: January 24, 2023, 12:24:30 pm
content: I know you don't have google where you are.Have you heard of Baidu?www.baiduinenglish.com/baidu-translate-and-how-to-use-it.html夜校?

author: Terry Bites
author_rank: Super Contributor
timestamp: January 24, 2023, 12:25:11 pm
content: There is no google in China....

author: wasedadoc
author_rank: Super Contributor
timestamp: January 24, 2023, 12:27:37 pm
content: Quote from: bidrohini on January 24, 2023, 11:38:28 amNot always uniform. Eg logarithmic law pots as typically used for volume controls.

author: magic
author_rank: Super Contributor
timestamp: January 24, 2023, 12:32:06 pm
content: I always assumed that the gold end of a resistor is the cathode.And I always mount THT resistors this way if they work with DC.I don't care what the smartasses say, it's just the right thing to do.

author: brabus
author_rank: Frequent Contributor
timestamp: January 24, 2023, 12:44:43 pm
content: 42.

author: BeBuLamar
author_rank: Super Contributor
timestamp: January 24, 2023, 12:50:41 pm
content: Quote from: magic on January 24, 2023, 12:32:06 pmI have a lot of resistors that don't have the gold end so I assume either end are the same. Is that OK?

author: xrunner
author_rank: Super Contributor
timestamp: January 24, 2023, 01:11:36 pm
content: Quote from: imcute on January 24, 2023, 09:35:40 amI know color coding, but you didn't state if the resistor was an SMD (surface mount) device. If it is, then color coding won't help you.

author: pcprogrammer
author_rank: Super Contributor
timestamp: January 24, 2023, 02:11:52 pm
content: Quote from: magic on January 24, 2023, 12:32:06 pmI align them with the tolerance ring too, but that is pure esthetics

author: wasedadoc
author_rank: Super Contributor
timestamp: January 24, 2023, 02:16:00 pm
content: Anyone buying a Hi-Fi amplifier for $5000 should check that all the resistors are fitted with correct polarity.

author: mikerj
author_rank: Super Contributor
timestamp: January 24, 2023, 02:29:05 pm
content: Quote from: BeBuLamar on January 24, 2023, 12:50:41 pmThose are dual anode parts.

author: BeBuLamar
author_rank: Super Contributor
timestamp: January 24, 2023, 02:30:00 pm
content: Quote from: wasedadoc on January 24, 2023, 02:16:00 pmGold band resistors are 5% I would expect such an expensive amp would have higher precision resistor than 5% and in which case I wouldn't know the polarity right?

author: TimFox
author_rank: Super Contributor
timestamp: January 24, 2023, 02:39:31 pm
content: Back in the day, National Radio Co (a respected vendor of short-wave receivers) made a point in their advertising that all their color-coded resistors were installed with the color bands in the same orientation.They also stated that it made no technical difference, but was an indication of their assembly quality.That reminded me of the rock bands that demanded that the M&Ms supplied in their hotel rooms exclude the brown ones.The logic there was that if the hotel didn't obey that demand, they probably omitted other demands as well.

author: Haenk
author_rank: Super Contributor
timestamp: January 24, 2023, 02:47:11 pm
content: Quote from: wasedadoc on January 24, 2023, 02:16:00 pmNot kidding - my DENON SACD-player (which had a list price of 1.5k back then) had the caps and stuff all bent in various directions - from factory. I certainly had that optically fixed when I swapped the laser. I mean, that's not some 20 EUR player, is a clean and tidy build too much to ask for?

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 24, 2023, 02:56:08 pm
content: There're lots of potatometer models, better you ask at your local grocery shop.

author: magic
author_rank: Super Contributor
timestamp: January 24, 2023, 05:23:23 pm
content: Quote from: BeBuLamar on January 24, 2023, 02:30:00 pm1% has brown bands instead.If there are brown bands on both ends, then you are screwed.Rant: in all seriousness, some 1% resistors really aren't making it easy

author: inse
author_rank: Super Contributor
timestamp: January 24, 2023, 06:40:37 pm
content: Especially when they are from the E48 or E96 series

author: james_s
author_rank: Super Contributor
timestamp: January 24, 2023, 06:50:45 pm
content: Quote from: pcprogrammer on January 24, 2023, 02:11:52 pmI do that too, I'm kind of OCD I guess. Whichever way I install the first one, I install all the rest with the tolerance band facing the same direction. I know it makes no difference electrically but I think it looks more tidy.

author: pcprogrammer
author_rank: Super Contributor
timestamp: January 24, 2023, 07:12:36 pm
content: Quote from: james_s on January 24, 2023, 06:50:45 pmI have the same tendency with smd resistors. The text needs to be in the same orientation for them. Obsessed of course notFound the website I initially wanted to mention.https://kiloohm.info/eia96-resistor/96CHas been very useful during the reverse engineering of the different scope schematics.

author: SL4P
author_rank: Super Contributor
timestamp: January 25, 2023, 04:23:51 am
content: QuoteThat’s why potentiometers were invented…If you put them in backwards, you can adjust the error out.

author: Ian.M
author_rank: Super Contributor
timestamp: January 25, 2023, 07:46:09 am
content: Quote from: magic on January 24, 2023, 05:23:23 pmThis nearly bit me in the but again yesterday - a 230V SMPSU startup resistor had failed open, and it was color coded: Brown Red Black {burnt} Brown, with no notably thicker bands or differences in spacing to give a clue which end to start.As the resistor had been covered in degraded yellow PCB snot, it was very difficult to read, and the burnt band could have passed for black. After much head scratching and some dissipation calculations I took a chance on it being 120K, (as 10K to 19K was unlikely) which brought the PSU back to life. Finally it was replaced with 3x 39K in series as I suspected it had gone open due to transient overvoltage so wanted to get the voltage per resistor down to well under 200V.

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 07:20:06 am
content: Quote from: Halcyon on January 24, 2023, 10:27:38 amWhat's a watch list?

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 07:22:41 am
content: Quite helpful,thanks!Another tutorial on the net says that the long pin is the cathode and the short pin is the anode.That one would be helpful if my resistors had pins of varying length(my resistors only have 3 pins and i can't see the difference in their length)

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 07:24:38 am
content: My resistors look like black cuboids.Each of them has 3 pins of uniform length under them.

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 07:28:35 am
content: OH NO ARE RESISTORS SO DANGEROUSI heard someone say that stuff with an unequal amount of cathodes and anodes would make a poisonous gas of weight 48.I'd better check my resistors too---they have 3 pins,so one is cathode the other is anode,so the third one is diode?or is the third one one of cathode and anode that makes poisonous gas?

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 07:30:00 am
content: they say that they only sell potato batteries which have no polarity,and they don't sell potentiometers

author: pcprogrammer
author_rank: Super Contributor
timestamp: January 28, 2023, 09:05:08 am
content: Quote from: imcute on January 28, 2023, 07:22:41 amCall them legs instead of pins and we know you are pulling ours

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 09:09:15 am
content: Quote from: pcprogrammer on January 28, 2023, 09:05:08 amI don't quite understand your reply?

author: pcprogrammer
author_rank: Super Contributor
timestamp: January 28, 2023, 09:17:51 am
content: Quote from: imcute on January 28, 2023, 09:09:15 amI meant that I suspect you are fooling us. Read my reply here:https://www.eevblog.com/forum/beginners/do-potontiometers-have-various-resistances/msg4658179/#msg4658179Resistors don't have anodes or cathodes. The example with different lengths of pins (legs) refers to LED's.Furthermore, poisonous gas, come on, magic smoke maybe when pushing the power limits and sure not good for your health but your post makes no sense.Quote from: imcute on January 28, 2023, 07:28:35 am

author: imcute
author_rank: Newbie
timestamp: January 28, 2023, 09:33:37 am
content: yeah its an electroboom memelots of you understanded it and responded jokingly toomaybe next time i shouldn't post it in the ask for help section?

author: RJSV
author_rank: Super Contributor
timestamp: January 28, 2023, 10:23:34 am
content: WATCH LIST:That just means that they gonna 'retire' you to the 'IWT' categories, a la School Report card listing as,'Inattentive / Wastes Time' box checked.Plus, (seriously), your original post puts a worry, on those charged with supervising the whole mess ...thanks.

author: BillyO
author_rank: Super Contributor
timestamp: January 28, 2023, 03:27:40 pm
content: Quote from: imcute on January 28, 2023, 07:20:06 amOmegaRolexPulsarMontblancCartierTimexPiagetSeikoVostokCasioCitizen...