EEVblog #755 - Fluke PM2812 PSU Ebay Score - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 05:17:37 am
content: Dave checks out a Fluke/Philips PM2812 System DC Power supply he scored from ebay for 30 bucks.Does it work?Will the bunker hardware tin collection come through?Service manual:http://www.eevblog.com/files/philips_pm2811_pm2812_pm2813_sm.pdf

author: Yansi
author_rank: Super Contributor
timestamp: June 19, 2015, 06:36:03 am
content: The 110/220 jumperlink only selects between full bridge rectifier and voltage doubler configuration. The PSU works on 330DC on both voltage systems. Absolutely common input circuit, also well known from a dual system PC switchmode supplies? So why the need to change anything else on the board or even to use a stepdown transformer to those yankee 110V? :-)The board is NOT designed for 110V only. The board can handle BOTH voltage systems. Only the jumperlink needs to be changed as you did. The 220V position is really to be open. See below://by the way: someone can't draw the electrolytic caps right. The filled rectangle is always minus pole. I took the first image google returned :-)and lol I just see, there's an error, I'll correct it for you :-)

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 06:37:35 am
content: Quote from: Yansi on June 19, 2015, 06:36:03 amIn this case you have to change both the input wiring and that jumper.It's actually in the manual wiring diagram if you look close enough

author: quarros
author_rank: Regular Contributor
timestamp: June 19, 2015, 06:59:54 am
content: Wouldn't EM interference/radiation be a problem with a wooden case? This is a powersuply afterall.Edit: Never mind.

author: Yansi
author_rank: Super Contributor
timestamp: June 19, 2015, 07:10:28 am
content: Dave, I don't know what are you talking about. The voltage selection does only the jumperlink.I have the SM opened right now and I can see that the board was possibly redesigned too. I don't see there any other spade lug there in the video. Nor is the jumperlink drawn in the SM.There is no way to need to change 2 wires at once. The 110/220V change is usually done via a SPST switch. If there is need to change two wires, I'd like to see the schematic how was that done :-oIn this version of board you disconnect the wire from the bridge and connect it between the two caps.In your version of board, the jumperlink is the selection shorting half of the bridge to make it a doubler.What else do you need to change, than that jumperlink you have already changed? Am I missing something?

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 07:45:57 am
content: Quote from: Yansi on June 19, 2015, 07:10:28 amYes, look at your wiring diagram above, you have to change the input wiring from the mains filterandthe jumper to the 220V position. It tells you right on the text on the diagram how to configure it. The extra spade lug is hidden behind the capacitor in your screen capture. It is as per the wiring diagram with the 3 lugs in addition to the jumper.

author: Yansi
author_rank: Super Contributor
timestamp: June 19, 2015, 07:56:27 am
content: I see it (there is also a whole paragraph about that in the SM), but clearly there is no reason obvious for me, why would you need to chnage TWO wires insted of only disconnecting the jumperlink.Can you please reverse-engineer schematic of the input stage? (from the socket to the caps). I'd be quite interested to see how the Fluke guys screwed the design that 2 wires need a change instead of one as usual. O_o

author: MrAureliusR
author_rank: Unknown
timestamp: June 19, 2015, 08:35:15 am
content: This is the series of power supply that free_electron sent me all that time ago, albeit the single channel version. The thing has been nothing but a tank! Works perfectly every time. Mine is the PM2811. I recently picked up a PM6666 Timer/Counter and a PM3052 60MHz scope to match.Thanks again free_electron! Dave, if you want to see inside a reference unit for any reason, let me know.

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 09:25:10 am
content: One on ebay for $159, bargain.http://www.ebay.com.au/itm/Philips-PM2811-DC-Power-Supply-/221785830466

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 09:27:27 am
content: This one has binding posts on the bottomhttp://www.ebay.com.au/itm/Philips-PM2811-/400896940828?pt=LH_DefaultDomain_0&hash=item5d5751db1c

author: MrAureliusR
author_rank: Unknown
timestamp: June 19, 2015, 09:59:29 am
content: Quote from: EEVblog on June 19, 2015, 09:27:27 amYeah, that was an optional extra, these really were designed to be rack-mounted units. I hacked up a binding post attachment that brings them out front.

author: Hamster
author_rank: Regular Contributor
timestamp: June 19, 2015, 10:59:40 am
content: Anybody know where the schematics are for the actual "Power Module" , how hard would it be to convert a 60V/5A to 30V/10A ?? The Software programming can be changed easily, but i am not sure what is different on the power module.Looks like two power modules:30V - 10 A60V - 5 A , and to get 60V 10A, it just combines two 60V/5A modules. ( or Series two 30V/10A modules )I have the tripple 60v/5a but really need a tripple 30v/10a unit.

author: miguelvp
author_rank: Super Contributor
timestamp: June 19, 2015, 11:39:26 am
content: Quote from: Hamster on June 19, 2015, 10:59:40 amBAMA (The Boat Anchor Manual Archive) has a lot of documents for Philips (Fluke) pm power supplies:http://bama.edebris.com/manuals/philips/But the closest to the PM2812 is the PM2811 but it covers both, but I'm not sure it has the schematics for everything inside, but the other ones might use the same modules.

author: lewis
author_rank: Frequent Contributor
timestamp: June 19, 2015, 12:02:29 pm
content: Real schoolboy error on that power supply Dave, that configuration is not only very common but almost universal in non-PFC dual voltage switched mode supplies. Can't believe you haven't seen that before!

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 12:39:42 pm
content: Quote from: lewis on June 19, 2015, 12:02:29 pmMeh. With hindsight of course I have seen it before, it just didn't come to mind. But it seems it's not that common because it's a combo of both the jumper and the input wiring config.If I had bothered to check the actual layout, I would have twigged.

author: lewis
author_rank: Frequent Contributor
timestamp: June 19, 2015, 12:42:15 pm
content: Not to worry, everyone makes mistakes, that's why the put rubbers on the end of pencils. And that's why I edited my post

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 12:44:23 pm
content: Quote from: miguelvp on June 19, 2015, 11:39:26 amNope, same one I posted. No PSU or control circuit

author: EEVblog
author_rank: Unknown
timestamp: June 19, 2015, 12:48:10 pm
content: Quote from: lewis on June 19, 2015, 12:42:15 pmThere are mistakes in every one of my videos, I guarantee it. My care factor has always been pretty close to zero, if it wasn't I'd go insane and/or never finish anything.I press record, I talk about what I see at the time, I check hardly anything during edit, then I upload.

author: Mark Hennessy
author_rank: Frequent Contributor
timestamp: June 19, 2015, 01:29:22 pm
content: I do a lot of work with power supplies, and as has been pointed out, the link (or a SPST switch) is pretty standard. In 240V mode, the link is O/C and the bridge does the usual thing. With the link in place, two diodes of the bridge cease to do anything, and the other 2 form a voltage doubler. In both modes, you get ~325V across the series combination of the smoothing caps.Looking carefully at the manual - and without the actual thing in front of me - I can only assume that the Input Module has changed from that detailed in the manual (common with Philips/Fluke gear of that era). For that version, I bet that when in the 120V position (X4106), Neutral is going to the junction of the smoothing caps, whereas in the 240V position (X4102), it is going to one of the AC inputs of the bridge. Functionally, it's the same change that adding the link does in the example schematic in post #2 - just another way of implementing it.I have *never* seen a PSU that requires both a link and an input change. But, there's a first time for everything; if you're sure that this one does, can I add my voice to those who wish to see a reverse-engineered schematic (won't take 5 minutes - just the stuff up to and including the big caps).Is the spade post behind those caps labelled X4106? If so, perhaps it's a "legacy" thing? If my guesses are right, then the Neutral wire can be left on X4102 when the link is made (120V position). With the Neutral on X4106, the link status would be "Don't Care" - it is 120V operation, whatever the link says. Perhaps a bit risky! Maybe that spade post now serves some other primary-side function - AC fan, extended hold-up, DC operation? Who knows?

author: Wim_L
author_rank: Regular Contributor
timestamp: June 19, 2015, 03:25:30 pm
content: I think the EEVblog has a new slogan: "More couch feet!"

author: MrMetthew
author_rank: Regular Contributor
timestamp: June 19, 2015, 04:25:23 pm
content: Dave, or somebody else, how do you keep finding these deals? Do you just search for random electronic related searchterms? Do you complete some kind of list, eg first search for scopes, than for sources, ... Or is there some kind of ebay sub catogory with most of these things in it? Cause I really wanna get in on some of this action!

author: ornea
author_rank: Unknown
timestamp: June 19, 2015, 04:44:31 pm
content: Quote from: MrMetthew on June 19, 2015, 04:25:23 pmI am also at a loss where people find these deals. I did see a condition subcategory of Faulty - Not Working on ebay.com. Cant find it now and never found it on ebay.com.AU. I believe it is an option when selling something so you should be able to filter on it as a buyer.

author: miguelvp
author_rank: Super Contributor
timestamp: June 19, 2015, 05:36:45 pm
content: The keywords should be "parts only" or "repair only"I guess you can combine them, like "power supply parts repair"

author: kcozens
author_rank: Contributor
timestamp: June 19, 2015, 06:29:13 pm
content: Early on in the video I noticed that daisy chain cable wasn't connected to the board. I also noticed that the 4 screw terminal block on the rear of the chassis for output 2 is missing two screws. Comparing it to channel 1 it is missing the shorting wire between -S and -V. You may be able to fix the channel 2 stability issue by replacing the two missing screws and adding a bit of wire to short the two terminals.

author: Hamster
author_rank: Regular Contributor
timestamp: June 19, 2015, 08:26:16 pm
content: I picked up a 2813/1103, 2811,2831 for $300 for all 3 . ( Yankee Dollars )

author: orion242
author_rank: Unknown
timestamp: June 20, 2015, 12:35:26 am
content: Couch feet, too funny!For the cover, maybe find a HVAC sheet metal shop. They might bend up something reasonable. Local metal fab around here would build a power coated AL single for ~$500 if I had to guess. Not a great option unless your think the resale value would justify.

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2015, 01:08:35 am
content: Quote from: MrMetthew on June 19, 2015, 04:25:23 pmThe easiest way is to simply search the category you are after and select "For parts or not woking", or you can search all categories in Electrical if you want.I also have a list of (some of the more obscure) brands that I regularly search for just to see if something pops up.I also have targeted email alerts for specific things I have looking for. You could do this for Non-working stuff too if you were keen.

author: EEVblog
author_rank: Unknown
timestamp: June 20, 2015, 01:09:40 am
content: Quote from: kcozens on June 19, 2015, 06:29:13 pmIt's not that, I put in proper screws you didn't see on camera.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 20, 2015, 01:45:08 am
content: Quote from: ornea on June 19, 2015, 04:44:31 pmeBay has email notifications of searches you want to "follow".

author: Tothwolf
author_rank: Regular Contributor
timestamp: June 20, 2015, 06:06:48 am
content: Quote from: miguelvp on June 19, 2015, 05:36:45 pm(fluke,tektronix,tek,hp,hewlett,hewlet,packard,agilent,keysight) (power-supply,powersupply,psu) (part,parts,repair,faulty,asis,as-is) -(atx,ac-adapter,charger,deskjet,printer,proliant,compaq,001)

author: Kleinstein
author_rank: Super Contributor
timestamp: June 20, 2015, 02:48:51 pm
content: The 19" size is pretty standard. So there is a chance that the cover from an other instrument that's beyond repair may fit. Other wise I would stick to a metal cover because of EMC and continued protection against fire.The schematics shows a funny detail on how read back of voltage and current is done: it's not using a normal ADC, but the DAC and 2 comparators. Really ancient way of doing things. So don't expect a high resolution / accuracy on the readings.

author: k2teknik
author_rank: Regular Contributor
timestamp: June 20, 2015, 04:30:13 pm
content: Quote from: Kleinstein on June 20, 2015, 02:48:51 pmWhy not? Successive approximation ADC are not bad, they may be slow compare to the way things works today.It is just a system PSU does it had to be fast for general purpose?

author: free_electron
author_rank: Super Contributor
timestamp: June 20, 2015, 05:19:59 pm
content: These supplies truly are tanks. Virtually indetructable.I still have one left. I gave a few away and sold a bunch. I had like 8 or 9 of em.I have thefull schematic somewhere on paper.

author: EvilGeniusSkis
author_rank: Regular Contributor
timestamp: June 20, 2015, 07:31:06 pm
content: maybe we should all mail Dave some couch feet for the mail bag.

author: Vgkid
author_rank: Super Contributor
timestamp: June 20, 2015, 07:54:34 pm
content: Thanks for the video. Funny enough the ribbon cable was the first thing I noticed.

author: ornea
author_rank: Unknown
timestamp: June 21, 2015, 12:01:18 pm
content: Happy Birthday.

author: Arie
author_rank: Newbie
timestamp: May 30, 2017, 07:26:32 pm
content: Dear reader,I am also looking for a diagram from the power module from a PM2812. Did you find a diagram?Best regards,Arie

author: Arie
author_rank: Newbie
timestamp: May 30, 2017, 07:32:16 pm
content: Dear reader,I am also looking for a diagram from the power module from a PM2812. Did you find a diagram?Best regards,Arie

author: ober
author_rank: Contributor
timestamp: May 04, 2018, 04:01:04 pm
content: So was the mystery of the X4106/X4102 swap for the blue wire plus the separate 110/220 jumper ever solved?My PM2811s have both the black jumper and a free spade near the blue wire...

author: ober
author_rank: Contributor
timestamp: May 23, 2018, 09:09:55 pm
content: The mystery has since been cleared up in a different thread:https://www.eevblog.com/forum/reviews/phillipsfluke-pm2811-power-source/So you move both the black wire on the lug marked 110 V to the 220 Vlug and the blue wire as marked in section 3.1.5 of the service manual(from X4106 to X4102).I can confirm that this works for moving US-spec PM2811 supplies to230 V.Don't forget to change the fuses (although the supply of course willwork on 230 V with the larger fuses needed for 110 V, justdangerously). Yes, there are a total of two, same-spec fuses thatneed to be swapped... The rating is dependent on the number ofchannels (PM2811: 1.25 A, PM 2813: 3 A, slow-blow).As the original fans in my supplies were audibly lamenting their age,I also put in new ones: NMB Technologies Corporation2410SB-05W-B20-B00 24 V fans (one needed for PM2811, three forPM2813), using Molex 90156-0142 plugs and 90119-2109 crimp inserts tocable them up.