Resistors  - Page 1
Forum section: electronics / beginners

author: Irilia
author_rank: Regular Contributor
timestamp: August 29, 2024, 03:46:21 am
content: I'm looking for ordering some 5% and some 1% resistors and I was thinking to order these value for the 3 category O kO MO (I know some are not available in 5 like like 47 but not 45 are available) so do you think it's to much for example i should stay without the 5 (it's for prototyping only) like for 155 I use 100+50+5 ?This is the list I was thinking about:1 2 3 4 5 6 7 8 910 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950Thanks for your help.

author: ArdWar
author_rank: Frequent Contributor
timestamp: August 29, 2024, 04:15:13 am
content: What's wrong with staying within E24 values? The (almost) logarithmic steps is also much more useful in real world compared to your regular steps.

author: ataradov
author_rank: Super Contributor
timestamp: August 29, 2024, 05:07:18 am
content: I got tired of not having resistors and simply bought all E24 values from 1 Ohm to 10 MOhm. All values in 0603 package at 1000 pcs cost around $130 from LCSC .

author: Irilia
author_rank: Regular Contributor
timestamp: August 29, 2024, 05:25:33 am
content: I wasn't knowing about it, but this looks crazy for me 👀

author: ataradov
author_rank: Super Contributor
timestamp: August 29, 2024, 05:30:03 am
content: You can get all E12 values if E24 is too much. In any case, sticking to standard series values is a good idea.Also, 5% is a waste of money. 1% resistors are super cheap anyway, so just get 1% and be done with that.

author: ArdWar
author_rank: Frequent Contributor
timestamp: August 29, 2024, 05:43:31 am
content: Even usage within E24 values aren't uniform. A "normal" circuit designs are more likely to use 10, 22, 33, 47 values way more often than other values while say 68 is almost never used.

author: Irilia
author_rank: Regular Contributor
timestamp: August 29, 2024, 05:44:53 am
content: Noted sticking with 1%

author: ataradov
author_rank: Super Contributor
timestamp: August 29, 2024, 05:49:15 am
content: E24 contains good set of values for combinations. Sure, you will favor some values in normal design. But there was a number of times when I needed some strange value (usually some biasing resistors). And having all the values was very useful, since I could get the value I needed with just a couple resistors.And $130 for a lifetime supply of resistors is not that much. Plus you can skip stuff on the high end. I just bough them for completeness.

author: tycz
author_rank: Regular Contributor
timestamp: August 29, 2024, 06:30:00 am
content: You can buy the whole E24 range of resistors in a little sample book that has 50 of each value. I have one each of 0402, 0603, and 0805 sizes, and another three for the capacitors. I don't know if they are available for through hole parts, but I've always made my own books for these (one ones that are meant to hold trading cards, nine plastic pockets per page). It takes up little space and makes everything easy to find.

author: Haenk
author_rank: Super Contributor
timestamp: August 29, 2024, 07:05:41 am
content: Due to eyesight, I prefer THTYou can get a pack of 100 .25W 1% for about 1,30 EUR *shipped* on Aliexpress.I also do like the complete sets of 3000 resistors for 10 EUR (again, that's *shipped* and tax included), they make a great starter kit and another 20 resistors will easily find their place in the drawers. Of course you will only need half of the values, ever.However, you do not know the manufacturer or specs, but they seem to be pretty much all within 1%, very rarely like up to 1.5% - so no reason to go with 5% when these are so cheaply available.(With LCSC you have a far greater bandwith of genuine products to chose from, however the shipping and tax makes that very expensive for my private orders.)

author: sleemanj
author_rank: Super Contributor
timestamp: August 29, 2024, 08:24:04 am
content: I keep roughly a lower-half set of e24 (1.0, 1.5, 2.2, 2.7, 3.0, 3.3, 3.9, 4.7, 5.1 in 6 decades) and just series/parallel combos with my resistor tool for the resthttps://sparks.gogo.co.nz/resistor_paralleler.html

author: ArdWar
author_rank: Frequent Contributor
timestamp: August 29, 2024, 09:30:04 am
content: Quote from: ataradov on August 29, 2024, 05:49:15 amThe idea is to buy a certain amount of E24 values, but maybe 10x more for the common 10s and 47s for example.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 29, 2024, 09:47:32 am
content: Quote from: ataradov on August 29, 2024, 05:49:15 amPower supply feedback divider (voltage setting) and ADC input scaling are typical examples where any arbitrary value is needed. So either you get full E24 series like you did, or you end up having to do parallel/series combinations in every other project.If you only do one-offs, you will save a bit by ordering less than 1000pcs, say, 100pcs but the difference isn't big. Or you can buy 100pcs of full E24 and then 1000pcs of some most used values (say, 22, 47, 100, 220, 470, 1k, 2.2k, 4.7k, 10k, 47k, 100k). But what you did is probably most sensible thing to do, easy to just order enough of everything and have the convenience of not having to think about it much after that.

author: ivo
author_rank: Regular Contributor
timestamp: August 30, 2024, 01:15:25 pm
content: Grab a cheap set of a few thousand E12 series 1/4w THT resistors for general prototyping.I like having some extra of 1 x 10nand 2 x 10nas well.Even cheaper you can get sets of 0805 or 1206 (a little bigger, easier to solder with) but they can be small / annoying and don't have the leads, so annoying for breadboarding.When you need good resistors, order them specifically for your project when you know you need them.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 30, 2024, 08:37:42 pm
content: Aliexpress has "SMT books" with assortments. Whole E24 and 100 pieces per value for around EUR30. There are also books with transistors, LED's and others.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 31, 2024, 07:25:09 am
content: Quote from: Doctorandus_P on August 30, 2024, 08:37:42 pmI have three such sets; 0402, 0603 and 0805. The risk of counterfeits or mislabeled is there, but I think it's the lowest with resistors. I have had no problems. I would not buy such transistor or LED "book".100pcs is awkwardly small number, if you need to say populate 10 prototype boards with 5 resistors each and then lose some, you are already low on stock for some single value. Then again, you can just add that particular part to your next Digikey/Mouser order, this has been working for me.