Anything to salvage here?  - Page 1
Forum section: electronics / beginners

author: scolecite
author_rank: Newbie
timestamp: November 25, 2010, 02:36:57 am
content: Hi I'mverynew to electronics and this was salvaged from a UPS system. I also saw it was hole through, so Im hoping there is something I can salvage.1. Is there anything dangerous that I should be aware of. (I have careful with it so far, Im not gonna take any chances)2. If you could tell me what you would take off this board I would appreciate it?The two big brown caps say 50V 1000uf. If you have any questions please ask!Thanks!

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 25, 2010, 03:19:00 am
content: That looks like the board out of an old UPS that used a ferroresonant transformer. (The new ones use PWM to generate sine waves.) There are no large high voltage capacitors on the board, unlike the newer ones. (There might be a large high voltage capacitor connected to the transformer, just check for voltage using a multimeter before handling.)As for parts to salvage, the relays and power MOSFETs can be very useful. The ferroresonant transformer itself, if you still have it, can be reused if you can figure out the windings. And the board can be used for soldering/desoldering practice. (Indeed, anything that is not bad can be salvaged. It's just that salvaging small resistors isn't worth the time unless you're going to practice desoldering.)

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 25, 2010, 05:46:29 am
content: the many legged bugs on there look expensive

author: Psi
author_rank: Super Contributor
timestamp: November 25, 2010, 08:06:30 am
content: all the mosfetsrelays, looks like one black one and maybe 3 blue onesthose two 40A fusesdb9 connectorred ledheatsinkslittle black speaker/beeper bottom right-

author: arcom
author_rank: Contributor
timestamp: November 25, 2010, 03:57:30 pm
content: In addition to above mentioned parts I would add:all TO-220 devices even if they aren't MOSFETstwo bigger brown capstwo smaller black caps above 40A fusesbrown block cap on the left side (above black relay) and coil above the cap4-pin connector if you have a male socket with a cable on itAs for the 40-pin bug it looks like a micro from Philips/NXP by the looks of the logo so maybe it can be reflashed.

author: Mr J
author_rank: Regular Contributor
timestamp: November 25, 2010, 05:57:52 pm
content: I made my old UPS into a nice bench top triple power supply. Do you have the big transformer, that came in it?Check out this video as wellhttp://www.afrotechmods.com/reallycheap/UPS/UPS.htm

author: Mr J
author_rank: Regular Contributor
timestamp: November 25, 2010, 06:07:43 pm
content: here is the schematic

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 25, 2010, 07:07:42 pm
content: Quote from: Mr J on November 25, 2010, 05:57:52 pmscrapped ups circuit due to dead battery?recharging battery without any sensory? screwing the batt?

author: Mr J
author_rank: Regular Contributor
timestamp: November 26, 2010, 04:33:34 am
content: Quote from: shafri on November 25, 2010, 07:07:42 pmYep I know, I had the same thing happen to me the battery was dead and it cost more to get a new battery, shipping and time than to buy a whole new UPS at the corner office supply company. The only thing in the video, he didn't specify a voltage. As long as your at the float voltage and about C/3 should be fine for Sealed Lead Acid, Nicads or rechargeable alkaline only, so for this circuit with a 7 ohm resistor (I thought the fuse idea was novel) something around 500mAH (C/3) or 1AH (C/6) battery would fit well for this trickle charger application. For more info please check outhttp://www.national.com/ds/LM/LM317.pdfpage 18 current regulator application. I would also recommend using a regulated power supply to power this circuit, keep the voltage at a constant level.Also if you need to charge another type of chemistry battery like Lithium ion use a proper charging IC like a MAX8600A, the one in the video I would only use for Sealed Lead Acid, Nicads or rechargeable alkaline.

author: tyblu
author_rank: Frequent Contributor
timestamp: November 26, 2010, 06:37:23 am
content: To tell you the truth, if you're new to electronics, try to desolder everything on the board and salvage whatever you can. It's decent practice for soldering, you get free parts, and you also get to learn what different parts do. ("What's a varistor? A MOV!?")

author: gushh
author_rank: Newbie
timestamp: November 26, 2010, 01:03:58 pm
content: Quote from: tyblu on November 26, 2010, 06:37:23 amJust make sure you're working on a well ventilated area, your health is worth much more than any component you may find in that board.As a side-note I agree with re-purposing of components or boards, you don't have to be a beginner or a professional for that matter; it's about recycling (the real recycling, none of that "let's separate the paper from the plastic" nonsense they've got going on in some countries where it all ends up in the same landfill).

author: scolecite
author_rank: Newbie
timestamp: November 26, 2010, 05:37:41 pm
content: Thanks guys! I am new so I need as much practice as I can get. Now though thanks to you guys, I know whats probably best to try and save, vs what is more "desolder practice"Can you guys give any advice on the chips? Ive only messed around with a 555 timer chips. And I programmed a ATmega168 in the Nerdkits kit.The big chip is aPhilips P87C51FB-4N. Logic Function Number:87C51; Memory Size:256 B; Memory Type:RAM; Microprocessor/Controller Features:16000 bytes OTP PROM; No. of Bits:8ADC0848CCN- 8-Bit uP Compatible A/D Converters with Multiplexer Options - National SemiconductorUEAV0421360-2040B360-2002BLM324ANLow Power Quad Operational Amplifier4N25-X009OptocouplersAnything cool here???

author: Unknown
author_rank: Unknown
timestamp: November 26, 2010, 08:31:31 pm
content: My $0.02:Quote from: scolecite on November 26, 2010, 05:37:41 pmThis is a 8051-type micro controller (like an ATmega168). OTP means one time programmable (like a CD-R), so you can't reprogram it like a modern micro with flash. Even if you could, you would need to have tools like a programmer. Probably useless, except for something like solder practice.Quote from: scolecite on November 26, 2010, 05:37:41 pmLow end 8-channel analog to digital converter. Looks like a parallel bus, not great for interfacing with modern MCU's that lack an external memory interface, but usable. You could use it if you need more analog inputs than your MCU has available, but have plenty of spare digital pins. Buying a MCU with enough inputs is usually the cheaper solution, though.Quote from: scolecite on November 26, 2010, 05:37:41 pmPopular quad jellybean op-amp, quite versatile, but pretty cheap.Quote from: scolecite on November 26, 2010, 05:37:41 pmOptocouplers are used when you need galvanic separation, for example in switching power supplies, where the secondary side should be floating relative to the mains, but you want to switch the MOSFET on the mains side.

author: DJPhil
author_rank: Frequent Contributor
timestamp: November 27, 2010, 12:33:43 am
content: Quote from: tyblu on November 26, 2010, 06:37:23 amI strongly approve of this message!If you're just starting I'd recommend buying a couple types of solder wick and at least one solder sucker. Try out as much as you can to see what works best for you.Plated through hole can be very difficult to desolder, for easier stuff to start with raid a thrift store for something that's more than twenty years old. Older single sided through hole stuff is much easier by comparison with low end tools, i.e. no vacuum desoldering system.

author: Simon
author_rank: Unknown
timestamp: November 27, 2010, 02:17:20 pm
content: the simple answer is what do you want ? I used to completely strip boards when I could not get parts for love or money. only take off what you need. The resistors and caps are cheap, anything like transistors may be useful.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 27, 2010, 03:08:55 pm
content: I remember reading that OTP 8051s can be set to run code from external ROM.

author: Zero999
author_rank: Super Contributor
timestamp: November 28, 2010, 09:56:09 am
content: X-rays can be used to erase so-called OTP devices so if you know a doctor at the local hospital very well they may be able to help you.

author: DavidDLC
author_rank: Frequent Contributor
timestamp: November 29, 2010, 04:43:19 am
content: Use the next technique to desolder the stuff !!!I like it"http://blog.rhysgoodwin.com/electronics/electronic-component-salvage/

author: DJPhil
author_rank: Frequent Contributor
timestamp: November 29, 2010, 05:04:04 am
content: Quote from: DavidDLC on November 29, 2010, 04:43:19 amThis works well when I've tried it, just two things I'd add.* The mask is a good idea. When all the solder melts at once there's sometimes a big release of flux smoke and burning dust. If in doubt, I'd go outdoors.* Solder will splash all over the place, way more and way farther than I expected the first time. Be ready for this! It wasn't much of a safety hazard for me, but it did get tracked inside all over the carpet after being spritzed on the concrete outside.

author: ElektroQuark
author_rank: Unknown
timestamp: November 29, 2010, 07:15:04 am
content: I use this method. Just shake the board in a big cardboard box, so the solder can run over the place.

author: squeezee
author_rank: Contributor
timestamp: November 29, 2010, 08:51:07 am
content: I basically usethis method. Have the pcb in a vise, heating the back side and pulling the components with a pair of pliers or popping/flicking things off with angled tweezers. Although i'll still give a board a good whack on occasion to send things flying.Regardless of how you do it, it's a good idea to wear safety glasses/goggles, as you will eventually find solder flying at your face.

author: Murphy
author_rank: Regular Contributor
timestamp: November 29, 2010, 11:21:21 am
content: Solder popper works awesome if you heat from the component side of the board to keep the iron out of the way.

author: Lance
author_rank: Frequent Contributor
timestamp: December 01, 2010, 07:13:49 pm
content: Someone has likely suggested this already, but try and grab heat sinks wherever you can. I have a bin full of various heat sinks that I've pulled off of stuff, and it's incredibly handy to have around.