LCSC Bourns Potentiometers - Page 1
Forum section: electronics / projects

author: Pentoad
author_rank: Regular Contributor
timestamp: December 19, 2019, 05:24:22 pm
content: Would anyone recommend buying bourns potentiometers from LCSC? If I order 100 they are 28 pence each. If that's not a good idea is there any other place to get decent quality trimmers? The product I am developing has three trimmers on it and if I buy potentiometers from Farnell, it would make the product too expensive to be profitable. Vishay T93yb is 75p each not including vat.

author: GromBeestje
author_rank: Frequent Contributor
timestamp: December 19, 2019, 07:46:57 pm
content: I have never bought potmeters at LCSC, but I have bought various other components components at LCSC. I never had any issue. So I'd say it's a good to go.

author: Pentoad
author_rank: Regular Contributor
timestamp: December 19, 2019, 08:48:04 pm
content: I will give it a try, I don't think they will be genuine as genuine ones are usually over £1 each.

author: thm_w
author_rank: Super Contributor
timestamp: December 19, 2019, 11:35:47 pm
content: These?https://lcsc.com/product-detail/Precision-Potentiometer_BOURNS_3296W-1-103LF_10KR_C34846.htmlEverything from LCSC should be genuine, that we've seen and discussed here.Although, Bourns 3296 is commonly faked. You can even buy under the clone brand names, Bochen/Baoter/etc. But they are clearly of a lower quality internally.I've added some to my next order, maybe cut them open and compare to the Baoters to see if they match the genuine (there is a thread around with photos).

author: 1276-2449-1-ND
author_rank: Regular Contributor
timestamp: December 20, 2019, 03:47:03 pm
content: LCSC is a distributor for Bourns.https://lcsc.com/brand-detail/377.htmlBourns has a lot of distributors in China, especially Shenzhen where LCSC is based.https://bourns.com/support/sales-locationsThat's why there is a lot of Bourns parts from China. I wouldn't be surprised if they had manufacturing facilities there since that's where most of their customers (contract manufacturers) are.

author: 1276-2449-1-ND
author_rank: Regular Contributor
timestamp: December 20, 2019, 03:51:11 pm
content: Forgot to mention I bought a large number of those trimmer pots, but haven't got around to using them yet. They came packaged in the original tubes (unlike Tayda trimmers which are loose no matter how many you buy) and look okay.

author: Nauris
author_rank: Regular Contributor
timestamp: December 20, 2019, 04:11:25 pm
content: Quote from: 1276-2449-1-ND on December 20, 2019, 03:47:03 pmMaybe but I have personally never seen a Bourns potentiometer that is not from Costa Rica, even that LCSC photo clearly reads Costa Rica. Maybe they make all their potentiometers there?

author: thm_w
author_rank: Super Contributor
timestamp: December 20, 2019, 11:00:16 pm
content: Quote from: Nauris on December 20, 2019, 04:11:25 pmGood point. Some say Taiwan though too.

author: nctnico
author_rank: Super Contributor
timestamp: December 21, 2019, 12:37:28 am
content: Quote from: Pentoad on December 19, 2019, 08:48:04 pmI have bought 'Bourns' potmeters from China before. They are not the real deal and may have issues (like not being able to reach the maximum and minimum resistance limits). If this is for a commercial product then I'd stay away from cheap parts. Penny wise, pound foolish. If you need to recall your products the loss will be much bigger. A better way would be to get rid of the potmeters. Think about post-production testing & adjustment. Also if your product becomes too expensive from a 1.5 pound price difference then your margins are too thin to start with.

author: thm_w
author_rank: Super Contributor
timestamp: December 21, 2019, 01:11:43 am
content: Quote from: nctnico on December 21, 2019, 12:37:28 amUnless you have purchased those from LCSC your statement saying they were not the real deal is irrelevant.I do agree with your other points though.

author: Pentoad
author_rank: Regular Contributor
timestamp: December 23, 2019, 09:54:57 pm
content: The product is a balancer module for lithium cells which uses analogue electronics completely for reliability and cost saving. The potentiometer is compulsory for calibration and to allow the user to set whatever voltage they want. In my tests the setup managed to balance a pack to within 3mv. I can't see any way out of using the trimmers because using fixed resistors would mean that the system couldn't be adjusted or calibrated at all. I heard that multiturn trimmers sometimes just fail or go open circuit after a few years but don't know how much this happens.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: December 24, 2019, 03:32:37 am
content: i bought cheapest ever possible knockoff , around 10 cents, 3296W, haven't had any issue, have couple precision schematics using that cheapo, they run 24x7 couple years ... , but anyway it mean relatively nothing, one thing that i noticed are torque can be vary a lot, sometime like malfunction.is it possible to add a resistor between the wiper and a leg ?expensive option: a coded rotary switch with fixed resistors

author: OwO
author_rank: Super Contributor
timestamp: December 24, 2019, 04:16:18 am
content: Quote from: nctnico on December 21, 2019, 12:37:28 amFor a product with 4 potentiometers (think buck converter modules with V and I adjust), that's $1.5 x 4 = $6. If the rest of the BOM cost is $10, and assuming a 3x margin, that makes a $30 product almost $50, just for luxury potentiometers. Repeat with all other parts on the board and you may have a non-viable product.However I do agree with you that you should never skimp on passives and mechanical parts (connectors, etc) because you can't test quality into them. But don't understate the importance of parts cost optimization because by far the biggest cost shavings I've been able to do are parts substitutions. PCBA (BOM lines, number of pads) optimizations don't come anywhere close.

author: Pentoad
author_rank: Regular Contributor
timestamp: December 25, 2019, 12:00:13 pm
content: That's what I have done. I put a high value resistor between one of the legs and ground which will trigger the external alert system and prevent destruction of the customers battery if a pot fails. My next version of the product may use a microcontroller but unlike analog electronics, they can crash and I don't want to risk a battery fire because of that. Also, the atmega 328 only manages 10 bit which isn't precise enough for me.