10 turn pots - Page 1
Forum section: electronics / projects

author: Alex30
author_rank: Regular Contributor
timestamp: August 28, 2014, 09:36:31 am
content: Hey guys, just wondering if anyone has any comments about 10 turn pots. It seems like you can spend a lot of money (up to $15-20) on one if you want or you can get ones like this:http://www.ebay.com.au/itm/1-2-4-5PCS-500-1K-2K-5K-10K-20K-50K-100K-3590S-Rotary-Potentiometer-Pot-10-Turn-/111328204099?pt=LH_DefaultDomain_0&var&hash=item19ebad9543&_uhb=1.What's the major differences in terms of functionality and quality apart from the obvious? It'd be even more helpful if someone has worked with a relatively cheap 10 turn pot that they can recommend\shame.Basically all I want to use a pot like this for is varying an opamp input for voltage control, I'm not looking to accurately graduate the dial or anything like that either so exact linearity is not a huge deal.

author: Asim
author_rank: Regular Contributor
timestamp: August 28, 2014, 09:57:49 am
content: Well, I can tell you one thing I bought a cheapie 10k pot (10 turns) that looks exactly like the one in the link you provided. It has an 18 ohms minimum resistance when turned all the way down.( not good enough for my application)

author: German_EE
author_rank: Super Contributor
timestamp: August 28, 2014, 10:17:57 am
content: As with most things in life you get what you pay for. A high quality device from someone like Bourns will have a wirewound spiral track but the cheap versions use a track made from conductive plastic nd will probably not last too long. That eighteen ohm minimum resistance is probably because they use one wiper against the track rather than two or three.

author: tautech
author_rank: Super Contributor
timestamp: August 28, 2014, 10:25:04 am
content: If it is for a PSU, don't piss around with any cheap stuff.Get Bourns or similar asGerman_EErecommends.If it fails/plays up on a PSU, it will fry more money in components than you are trying to save.

author: Alex30
author_rank: Regular Contributor
timestamp: August 28, 2014, 10:28:52 am
content: 18Ohm minimum would probably not be a big issue to me. What would be a pain though is if they were faulty or broke quickly. I'm not quite willing to pay 15-20 dollars each when I need two of them. The major reason for building my own psu was to save moneyQuote from: Asim on August 28, 2014, 09:57:49 amThanks. Did your one go up to the full 10k give or take?

author: tautech
author_rank: Super Contributor
timestamp: August 28, 2014, 10:40:25 am
content: http://nz.element14.com/bourns/3590s-2-103l/potentiometer-10k-5-linear-2w/dp/1612611Why would you consider anything else?

author: liquibyte
author_rank: Frequent Contributor
timestamp: August 28, 2014, 10:45:20 am
content: Quote from: Alex30 on August 28, 2014, 10:28:52 amIf your plan was to save money by building your own, I can tell you first hand that you'll find it didn't work out quite that way. It is fun though.

author: Alex30
author_rank: Regular Contributor
timestamp: August 28, 2014, 10:55:41 am
content: Quote from: tautech on August 28, 2014, 10:40:25 amHm, that's not a bad price. Will certainly consider this one, I will bookmark this. Thanks for that.Quote from: liquibyte on August 28, 2014, 10:45:20 amHaha you're probably right.Edit:Thought I would throw this link in for laughshttp://au.rs-online.com/web/p/potentiometers/1645058/

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 28, 2014, 01:05:11 pm
content: http://www.ebay.com/itm/POTENTIOMETER-HELIPOT-10-TURN-30K-0-1-LIN-WITH-DIAL-/261078224039There's one that's half a century old in my scope and it still feels and works better than new ones.

author: macboy
author_rank: Super Contributor
timestamp: August 28, 2014, 04:01:04 pm
content: I bought some of those cheap knock-offs, knowing of course that they were knock-offs (of a Bourns 3296 series of course). They are garbage. The ones I got are that familiar blue square, and are labelled "BONENS 3296". Here are some other examples:

author: jlmoon
author_rank: Unknown
timestamp: August 28, 2014, 04:15:48 pm
content: Quote from: Alex30 on August 28, 2014, 09:36:31 amThose look like "Bourns or Allen-Bradley" knock offs

author: Pedram
author_rank: Regular Contributor
timestamp: August 28, 2014, 05:28:55 pm
content: Also cheap ones have mechanical backlash which is pain in the ass to set them precisely . if you really want to go down to the price. use three single turn pot in series. Coarse adjustment, fine adjustment and super fine adjustment.

author: nctnico
author_rank: Super Contributor
timestamp: August 28, 2014, 05:34:14 pm
content: Quote from: Alex30 on August 28, 2014, 09:36:31 amI think these are factory rejects from Bourns. I bought a couple and they have defects like not going to 0 Ohm but having a minimum of 10 Ohms. The ones I got have Bourns lasered in the rear and look genuine.

author: Asim
author_rank: Regular Contributor
timestamp: August 28, 2014, 08:08:49 pm
content: Quote from: Alex30 on August 28, 2014, 10:28:52 amyes they did (3 out of 3)

author: mariush
author_rank: Super Contributor
timestamp: August 28, 2014, 08:12:30 pm
content: TME.eu has some cheap 10 turn pots. They're brand name (though may not be some of the well known brands) so at least you don't get fakes or clones from eBay:http://www.tme.eu/en/katalog/passives_112309/#id_category=24&s_field=artykul&s_order=ASC&page=1

author: SArepairman
author_rank: Frequent Contributor
timestamp: August 28, 2014, 08:52:54 pm
content: https://www.eevblog.com/forum/chat/bonens-%28bochen-also-works-here%29-counterfit-bourns-trimpot-analysis/

author: Alex30
author_rank: Regular Contributor
timestamp: August 29, 2014, 02:43:25 am
content: Quote from: SArepairman on August 28, 2014, 08:52:54 pmQuote from: Pedram on August 28, 2014, 05:28:55 pmOh wow, can't believe I didn't think of these two potential issues lol. These issues would definitely be a major pain in the ass. I guess I'll try and get the ones tautech linked to.

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2014, 02:57:49 am
content: QuotePut a flag in your profile so accurate local recommendations can be made.No accurate search was made to find those pots, just "10 turn pot", then 10K and Bourns in the selection options and scroll to find the cheapest.Took 10 seconds.

author: Alex30
author_rank: Regular Contributor
timestamp: August 29, 2014, 03:10:31 am
content: Quote from: tautech on August 29, 2014, 02:57:49 amHeh, yeah just don't have that much experience with any retailers besides jaycar and rs components. Have you used element 14 before for postage to oz?

author: pickle9000
author_rank: Super Contributor
timestamp: August 29, 2014, 03:12:56 am
content: Mechanical backlash is also present on Bournes, they do sell a variant which has minimal backlash but cost is more and only available in 3 resistances. It's designed for use in string pots (measuring device).

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2014, 03:41:14 am
content: Quote from: Alex30 on August 29, 2014, 03:10:31 amI'm in NZ, not sure if they are still Farnell in AUS as they used to be here.No, here's the link:http://au.element14.com/bourns/3590s-2-103l/potentiometer-10k-5-linear-2w/dp/1612611

author: Alex30
author_rank: Regular Contributor
timestamp: August 29, 2014, 03:51:32 am
content: Quote from: tautech on August 29, 2014, 03:41:14 amSorry, only glanced at your flag there. Ok thanks!

author: tkuhmone
author_rank: Regular Contributor
timestamp: March 29, 2017, 07:34:24 pm
content: This thread seems to be good on my purposes alsoI got power supply for my use, and it has four multiturn 10k ohm pots where two needs to be replaced. So I will look at original Bourns from 3590S series...

author: tkuhmone
author_rank: Regular Contributor
timestamp: March 29, 2017, 08:10:51 pm
content: In the PSU I mentioned, the origin is propably from years approx 1992...1996 and those have been also in lab use. So that is pretty good expected lifetime for a good quality multiturn pot. Those old Bourns 3590S seem to be some level touch sensitive, at least when pushing the knob on the axle direction -> occasionally power supply output voltage is lost (I assume the center viper has not contact on wirewound resistor)