Salvaging ATX Power Supplies Wierd Part - Page 1
Forum section: electronics / beginners

author: MrWizerd
author_rank: Contributor
timestamp: September 11, 2015, 05:12:48 am
content: So I have been salvaging ATX Power Supplies for a bit now, to help me practice de-soldering. Most of them are cheap no name units with mostly no name parts in them. I opened one up today because I wanted to take a look at the mains surge protection, I have found different things on the mains like capacitors and I think thermistors, anyways, This unit did not have any of that, what it did have was a pretty nice little temperature controlled fan board which I am going to use on my new power supply kit I am waiting on. I am going to buy a good Bench Power Supply eventually but in the mean time am practicing my soldering with semi usable kits. The other thing I found was a strange transformer but it only had one input and I was confused as to what it was. I was able to search the part number which was FL-48-C075250 but found very little information and what I did find is in a language I cannot read, and am not sure of the google translation forhttp://www.pretragaoglasa.com/?q=Prigusnica+250w+i+C-28MF&start=30which linked tohttp://www.kupindo.com/Elektronika/18299677_PrigusnicaGoogle translated the first page to read the unit as a Silencer/Prigušnica the second page google translated it as a Muffler in the tab and restrictor in the description The pictured unit is the exact unit I have down to the millimeter and colour. The problem is I don' t know what it is, or if it is usful or if I should send it to be recycled. Anyone have any idea what this part is/does and/or how to test it and/or if I should keep or recycle it?

author: thejoggingmat
author_rank: Regular Contributor
timestamp: September 11, 2015, 05:20:56 am
content: Could it be an inductor?

author: bktemp
author_rank: Super Contributor
timestamp: September 11, 2015, 05:21:21 am
content: It looks like a passive PFC inductor.

author: lincoln
author_rank: Regular Contributor
timestamp: September 11, 2015, 05:22:26 am
content: >things on the mains like capacitors and I think thermistorsIf you found them where I think you did, they will be called "MOV"s> The other thing I found was a strange transformer but it only had one inputthat would be an inductor, also know as a choke, which is likely where google gets "muffler" from. Though I have never seen one look like this, It may be a line reactor, which is basically an inductor but is used to correct power factor rather than to filter noise.

author: Greg Robinson
author_rank: Regular Contributor
timestamp: September 11, 2015, 05:35:35 am
content: Yep, that's an inductor. Old terminology for inductors used in power filtering applications (in this case PFC) is choke, now often also called reactors when used for PFC (because it's the reactive component that is needed in this application). Here's alinkfor a wide variety of inductors, with many similar to the one you have come across.

author: fubar.gr
author_rank: Unknown
timestamp: September 11, 2015, 06:34:45 am
content: Quote from: MrWizerd on September 11, 2015, 05:12:48 amThese markings are usually the model number of the bare magnetic core. These can be wound in many different ways so these numbers are not very helpful.

author: MrWizerd
author_rank: Contributor
timestamp: September 11, 2015, 09:25:28 am
content: Thank you for all the prompt responses. I will look into it Moore and see if I can find a use for it. It sounds like in this situation maybe it was taking the 220 v option for the supply and choking it down to 110? I will look up more now that I have a name for them.The other item I was talking about are zinc oxide varistors, I have two types, the SCK-037 and 07K271. I have the data sheets for then both, I was thinking of using one of them before or after a fuse before a capacitor maybe to help protect from current/voltage surges before the 120 main makes it to the transformer. The cap to help clean any potential dirty power. I have been looking for circuit examples for this type of protection for the supply and something similar for the variable power/current outputs, so shorting the outputs or turning of the supply with a battery connected doesn't break this dinky little kit.http://www.ebay.com/itm/0-30V-2mA-3A-Adjustable-DC-Regulated-Power-Supply-DIY-Kit-Short-with-Protection-/381220459244?hash=item58c28292ecI figured I would put it in an enclosure with a volt meter and amp meter connected to the it's if I could manage it, I also salvaged the fan controller with thermal controls to add to it, and the transformer to power it. I picked up ten turn pots to replace the single turns, and better heatsink. I realize it's not as good as a commercial unit, which I am buying still but this is more for me and my son to assemble and figure I should make it a safe and as robust as I can within reason. Since I have all these parts from the salvaged ATX power supplies that I could use some of the surge suppression stuff I found which include the varistors as well as the fan circuit. Anyone have thoughts or a link to proper supply safety and surge suppression circuits?Sent from my SPH-L710 using Tapatalk

author: janoc
author_rank: Super Contributor
timestamp: September 11, 2015, 09:50:46 am
content: Quote from: MrWizerd on September 11, 2015, 09:25:28 amUm, no, that's what a transformer can do, not a choke. Choke is just a plain inductor, it is there to block any high frequency noise from the switching PSU from escaping to the mains wiring (think low pass filter).Alternatively, if it is a PFC inductor, it helps to correct the power factor of the PSU (these are now mandatory for new hardware since a few years).Basically, unless you have a need for such a large inductor for some reason, I would say the only use for those is to get the magnet wire from them. The core could be also re-used if you wanted to wind your own transformer for something.

author: MrWizerd
author_rank: Contributor
timestamp: September 11, 2015, 10:06:06 am
content: Quote from: janoc on September 11, 2015, 09:50:46 amIf I were to guess that winding my own transformer would not be an easy task would I be massively understating the situation? I remember making crude motors in metal shop in junior high and my wraps by far the best in class, and they looked terrible! My guess is that the wires have to be layed down precisely to work properly, an I wrong?Sent from my SPH-L710 using Tapatalk

author: GNU_Ninja
author_rank: Regular Contributor
timestamp: September 11, 2015, 10:15:00 am
content: That would be an inductor used for Power Factor Correction.This link will take you to a PDF of a handbook on this subject:http://www.onsemi.com/pub_link/Collateral/HBD853-D.PDF

author: poorchava
author_rank: Super Contributor
timestamp: September 11, 2015, 10:27:10 am
content: Quote from: MrWizerd on September 11, 2015, 10:06:06 amThis assumption is correct and wrong at the same time. There are transformers and inductors which are difficult to wind correctly on your own. If parasitic capacitance matters alot (high ratio + high voltage) or high voltage withstand capability is needed then it might be problematic. Other than that winding medium power magnetics is not that difficult when you get a hang of it.