Thurlby Thandar QL355 Power Supply - Page 1
Forum section: electronics / general

author: icon
author_rank: Regular Contributor
timestamp: July 27, 2012, 10:24:39 am
content: HiI bought a power supply. I've never had a 'proper' power supply, just home made LM317 things, so this is quite exciting for me. I got this from Ebay, advertised as BNIB. It's a QL355 - they do a programmable version and a triple, but this is the single output, non-programmable one. Here we go.Pretty well packaged:Comes with 2 power cords - a proper BS1363 one and some shoddy johnny-foreigner thing. Also a 'proper' manual. I haven't looked on the CD yet. They include a freepost envelope to return the non-recyclable packaging.Some people like to sniff new electronic things. For me, the ultimate pleasure is peeling protective layers off displays. I'm saving this one for later.Even on the base model you get alarm output (for the user-settable OVP/OCP). And look at all that goodness in there...I can't find much on-line about them, so I wondered - would there be any interest out there in a bit more detail/interior views?John

author: Dagon
author_rank: Regular Contributor
timestamp: July 27, 2012, 11:04:56 am
content: Nice. I picked up a EL302R as my first 'proper' power supply six months back. More basic then the QL355 but a quality bit of kit. Would definitely get more Thurlby Thandar stuff.

author: free_electron
author_rank: Super Contributor
timestamp: July 27, 2012, 01:01:41 pm
content: These supplies are also sold as xantrex or sorensen. I use the three channel programmble versions at work. They are excellent supplies. TTI is a british company that has been building supplies for a long time. The older series was based on Z80 processor with upd7210 gpib controller. They used optocouplers and an A/DD/A board with chips from PMI ( precision monolithics) and burr brown.Fully designed in the UK?This power supply i don't know. Never opened one... Maybe over a dead lunchtime moment i'll rip one apart...

author: MBY
author_rank: Regular Contributor
timestamp: July 27, 2012, 06:44:45 pm
content: I find it odd that the silk has all the designators for programmability such as local, addr and baud? And what does 35 V 3 A and 35 V 500 mA stands for, when its a single output device?

author: Salas
author_rank: Frequent Contributor
timestamp: July 27, 2012, 06:52:14 pm
content: Output on/off engage button there NATURALLY. Missing in many oriental ones and other. Powering down/up just to cut the rail while having to tweak something when working on a board is utterly annoying.

author: Monkeh
author_rank: Super Contributor
timestamp: July 27, 2012, 06:54:39 pm
content: That's not some shoddy plug, it's a CEE 7/7. One of the best general-purpose plugs going.Quote from: MBY on July 27, 2012, 06:44:45 pm1mA resolution on the 3A range, 0.1mA resolution on the 500mA range.

author: tom66
author_rank: Super Contributor
timestamp: July 27, 2012, 06:58:04 pm
content: Ugh, do I see Samwha caps? I've pulled almost 20 of those from at least 3 LCD and plasma TVs, they go bad pretty quickly. Hopefully TTi aren't using them for anything serious, and that they've got a good returns policy.

author: Dagon
author_rank: Regular Contributor
timestamp: July 28, 2012, 07:48:23 am
content: Out of curiosity I opened mine up. Any caps where I could see a name were Jamicon.

author: tom66
author_rank: Super Contributor
timestamp: July 28, 2012, 08:39:21 am
content: Jamicon make above-average general purpose capacitors (far better than Samwha), but I would have preferred to see some higher reliability caps, such as Nichicon, Panasonic, Rubycon, Chemicon ... especially for the price charged.

author: free_electron
author_rank: Super Contributor
timestamp: July 28, 2012, 04:09:43 pm
content: Quote from: MBY on July 27, 2012, 06:44:45 pmnot strange. these supplies can be bought with those options installedas for the caps in plasma's. those run very hot and get pulsed currents at high frequencies.which is not the case in this power suppliy. besides, cap manufacturers have many different product lines and stating a cap manufacturer is bad based one one cap in one application from one series is not correct.

author: tom66
author_rank: Super Contributor
timestamp: July 28, 2012, 04:54:43 pm
content: Quote from: free_electron on July 28, 2012, 04:09:43 pmThe culprit in the case of Samwha was likely either a manufacturing defect or marketing being too liberal with the specified ratings. It is true that they are under higher stress in an SMPS (it's pretty much the same for LCD or plasma) though the LG plasma I serviced used five of the 3300u 10V Samwha WB variant in parallel (so much lower stress per cap) and they still failed. And that was 5V, 3A output for the digital board.I believe it cost Samsung millions to fix the issue. Not sure if LG were that badly affected or if they did anything about it though. The 42" in my living room was a dumpster find with four bad Samwha WB.If a cap manufacturer has a bad run, I start being a little worried about their other caps, because that failure slipped past quality control processes that they should have had in place. Nichicon had a similar problem with Dell motherboards so I'm still not 100% on their quality but I've only ever seen one bad one on a motherboard; and there's a suggestion that those caps weren't actually made by Nichicon, but an outside contractor. (Possibly Samyoung.)

author: T4P
author_rank: Super Contributor
timestamp: July 28, 2012, 06:42:12 pm
content: Why? I trust nichicon!Come on, it might be a small thing after all, if they aren't being serious,they aren't meant to be called one of the best cap manufacturers, if not best.I use nichicon/panasonic/rubycon across all my prototypes and i know well their spot on quality, something japan is known for.(I threw out the OHL's in my parts rack)

author: tom66
author_rank: Super Contributor
timestamp: July 28, 2012, 06:57:08 pm
content: Quote from: DaveXRT on July 28, 2012, 06:42:12 pmIf you read the rest of my post, you'll see I do trust Nichicon caps.I have used them in several repairs.I mostly use Panasonic and Rubycon though because they tend to be a bit cheaper.

author: T4P
author_rank: Super Contributor
timestamp: July 28, 2012, 07:55:51 pm
content: Quote from: tom66 on July 28, 2012, 06:57:08 pmOh ... okay

author: Freighternut
author_rank: Regular Contributor
timestamp: July 29, 2012, 09:32:01 am
content: Enjoy you power supply!I have the TTi QL355T ( The two channel plus aux). I am very happy with this power supply!Having the digital entry plus the ability to jog makes it very versatile.When the Warranty runs out I may see what I can do to quieten the fans down a bit.

author: saturation
author_rank: Super Contributor
timestamp: July 29, 2012, 01:34:03 pm
content: Aim-TTi are quality supplies, and as well other equipment, if you can afford the premium price; it is cost effective though when you compare prices in the EU. Don't see many with 'Made in England' these days.

author: icon
author_rank: Regular Contributor
timestamp: July 29, 2012, 04:25:45 pm
content: Quote from: saturation on July 29, 2012, 01:34:03 pmI picked this up from Ebay for £160 delivered, which I thought was pretty reasonable, given what's generally available for that sort of price. The seller has sold others before, for around that price (one as low as £150, one for a bit more). They're mis-described in the title as 'QL335'.So far I'm very pleased with it. I have taken a few photos of its guts which I'll post in another thread, and I've had a look at its electrical behaviour with an oscilloscope. No funny business there, so far.CheersJohn