Nice Ebay deal (UK) on 5 power supplies (Electrophoresis )

[_Wim_]

http://www.ebay.co.uk/itm/Bio-Rad-Electrophoresis-Power-Supply-Power-pac-3000-and-200-/292048088449?hash=item43ff6c2d81:g:GgcAAOSw~AVYvoDa

2x 3000V 400mA, and 3x200V 2A Electrophoresis  power supplies. For 70 pounds, that seems very reasonable to me. No afflation with the seller, just thought is was a good deal for somebody in the UK.

[edpalmer42]

If you're buying an electrophoresis power supply for use just as an ordinary power supply, check the manual before buying the unit.  Some of them have features that are a nuisance for general use.

I picked up a Pharmacia ECPS 3000/150.  It goes to 3000V and 150W.  It works, but....
- It's actually +- 1500V and if the center point moves off ground, the unit shuts down
- It won't start if there's no load and it shuts down if the load drops below a certain value.  The start and stop thresholds are different.

Within those limits, it's a nice supply.  10 - 3000 V, 0.1 - 150 ma, 0.1 - 150 W.

I don't know if those features are common or unique.  Best guess is that older, dumber units might be easier to deal with.  YMMV

Ed

[_Wim_]

Good tip indeed to check the manual.

The no load thing is indeed common (is the same on my unit, a Statagene Smart Power 4000), but at least on mine, it seems happen with a minimum load of 500K, which is mostly not a real issue.

They are for sure not as good as a "real" high voltage power supply, but for 15£ a piece, it still seems a good deal for me (keep 1 or 2, and sell the others again on Ebay for 25£ a piece)

[edpalmer42]

Yes, if you can live with or bypass the annoying features, they can be an excellent value.  Mine was so cheap (US$25) that I just couldn't resist.  I don't regret the purchase at all.


Ed

[flash2b]

I have an LKB 2197, 2500V, 250mA, 100W



See: https://www.circuitsonline.net/forum/view/message/1513967#1513967

LKB is taken over by Pharmacia. This is actually a +/- 1250V power supply but always deliver output voltage even without a load. You can use it as such but it should remain a floating power supply.

[PointyOintment]

I have a 2197* (the version with four knobs for the timer—two of these on eBay currently) as well as an E-C Apparatus EC600 (4 kV, 200 mA, 200 W) and what turned out to be just the shell of a Fisher Biotech FB 600 (which did seem suspiciously light when I bought it, but I didn't know until I got the E-C that it was supposed to be so heavy I could barely lift it). The latter two are the same thing under different brands, also known as MRA M161, BRL 4000, OSP 4000—there seems to be a whole series of electrophoresis power supplies, from small basic models up to the model I have, all with the same pentagonal body shape, sold under a dozen brands or so. (I spent several hours looking for all the variations on eBay a few months ago when I got the Fisher one, looking for any clue toward a manual. I found a forum thread where somebody posted photos of the internals, and I got the idea of building the internals myself, but then I got the E-C one that had the internals, and realized that I couldn't have done that. I did eventually find the manual, but now I've lost it again.)

I got them all from the local government surplus depot. They've had several other models as well—I have photos of Bio-Rad 200/2.0, Bio-Rad 3000Xi (in pieces), 2× Pharmacia ECPS 3000/150, E-C Apparatus EC-400 and EC-458 (yes, with hyphens, while the EC600 is unhyphenated)—but I've stuck to ones that seem reasonably adaptable to electronics (auto CV/CC at least—some models are manual).

I haven't gotten around to testing either of mine yet, though I took apart the EC600 and photographed the internals extensively (and then never got around to reassembling it). I should post about them sometime.

*Some LKB Bromma 2197 info, in case you haven't found it, flash2b or anyone looking to buy one: http://www.radcomms.net/LKB_2197.html (operation manual, service manual, schematic); https://www.vintage-radio.net/forum/showthread.php?t=94181 (discussion of usage and mods, schematic, datasheet of PWM chip); http://antiqueradios.com/forums//viewtopic.php?f=8&t=235320 (discussion. Also, it seems LKB also sold the 3000/150 before being bought by Pharmacia. I've seen lots of the same products with LKB on one and Pharmacia on another at the surplus depot.)

[mikeselectricstuff]

Interlocks - I once spent an afternoon faultfinding one of these before I realised that the output sockets had switch contacts to disable it until there were plugs in all the sockets

[Mark]

Now then, what am I going to do with these?  Thanks to the OP for finding these, and thanks to the seller who also included a tank and shipped everything via UPS. 
I've been doing some research into PCRs and DNA analysis, it sounds quite interesting so these might get used for their original purpose after all, otherwise...
 

[_Wim_]

Glad to see somebody from EEVblog was able to get them  . Have fun on your DNA quest...

[PedroDaGr8]

Now then, what am I going to do with these?  Thanks to the OP for finding these, and thanks to the seller who also included a tank and shipped everything via UPS. 
I've been doing some research into PCRs and DNA analysis, it sounds quite interesting so these might get used for their original purpose after all, otherwise...
 

If you have any questions about running gels, then I can try and help. They tend to be finicky beasts, as you often are riding the edge of speed of elution and melting the gel. Some of the gels we used to run, we would stack ice packs all around them to keep the gel and buffer from boiling. While usually we purchased gels, we did make some of our own (agarose gels in particular). For SDS-PAGE and IEF gels, we tended to just purchase them.

Running the gels are only part of the process as the gel is traditionally perfectly clear (unless you have a highly colored sample). You have to develop the gel to see the results. You do that by staining the entire gel and the de-staining so that all that remains are the bands.

It is not an easy process but it does get some cool results.

[Mark]

They all work!  Just some missing lines/pixels on the LCDs but still useable.  The 3000V versions have a minimum current requirement easily met by putting a few hundred k ohms  across the output.  The output drops to zero when switched off.  The 200V versions are not as sophisticated, they do not have any minimum current requirement and can have a dangerous voltage at the output for quite a few seconds after switch off.  I have to say I am very pleased with this purchase, there is a lot of potential (pun) for learning about a completely new area for me. 
PedroDaGr8, thank you.  Just seeing some bands would be a very cool result! 

[Simon Spiers]

I have had a Pharmacia LKB ECPS 3000-150  under the bench for a while and finally got around to having a closer look at it yesterday.
As mentioned here this unit would not startup without load unless you wind it up to around 500V, useless. The other BIG danger was it has horrific overshoot under light load. The first test blew my Fluke 73's MOV!
I have made a quick youtube video to show you the overshoot problem and a fix to allow low voltage startup and reduce the overshoot problem.
Bare in mind i'm working blind as I have no info at all on this thing. It seems to use a TDA 1060 as a main control chip with various opamps for interlocks and control. I was expecting to see a PWM, but it all seems to be done by the 1060, although I cant fond where the pulses that switch the main switching transistor derive from.
https://www.youtube.com/edit?o=U&video_id=TdhIDwuvLNs