"New Guy Here" I have lot's of older, high end compontents if in need. - Page 1
Forum section: electronics / repair

author: Soxfan
author_rank: Newbie
timestamp: September 24, 2018, 02:32:16 am
content: This is my first post here. I work in a hospital and have access to all of the discarded medical equipment. They regularly use very expensive and hard to find parts. I have about 500 pounds of boards and even unsoldered components that I really don't know how to fully appreciate yet. The lowest end opamp I run into is op07. It became a hobby collecting and safely removing ic's. So as I learn from you folks, maybe I can help out as well. Shoot away if you have a chip or anything you need.I'm looking to try my hand at a 0-20v or 30v and 0-3 amps power supply build. I'm looking around a lot, but have yet to find a source I can trust to pour my time into. I have the input settled, but the dc regulation part is my focus. I know this is the wrong section, but figured I'd ask if anyone had a good design to share.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 24, 2018, 03:03:24 am
content: if you have op amps to sparehere's an design :http://www.electronics-lab.com/project/0-30-vdc-stabilized-power-supply-with-current-control-0-002-3-a/

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 24, 2018, 03:05:03 am
content: Unless you really just have to build it, a good CV - CC power supply is a lot to tackle for a beginner. All you have to do is search the threads here to see what many have run into. I haunted ebay for a few months and came away with some 2-3 channel PS at bargain basement prices. The liquidation of the ITT schools dumped a lot of pretty good equipment on the market. I picked up a few BK Precision 1651 triple output PS for no more than $50 shipped. Buying a "for parts only" unit and repairing it will teach you a lot too. No way I could design and build anything close to these.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 24, 2018, 04:07:09 am
content: I have answered this on another thread :You have some linear DIY pcb with all the parts on Ebay, as low as 5 $ usdhttps://www.ebay.com/itm/Red-0-30V-2mA-3A-Continuously-Adjustable-DC-Regulated-Power-Supply-DIY-Kit-PCB/201751652278This one seems very nice, feature packed, schematics available, Strange resemblance with mastech GW Instek psu's ??https://www.ebay.com/itm/Continuously-Adjustable-DC-DC-Regulated-Power-Supply-DIY-Kit-0-35V-0-5A/173417145714?hash=item286077a572:g:VKMAAOSwHt1bTujtCheck it out ?

author: tpowell1830
author_rank: Frequent Contributor
timestamp: September 24, 2018, 04:19:56 am
content: Quote from: Old Printer on September 24, 2018, 03:05:03 amThe OP never said he was beginner.If you have any of those ITT (BK Precision) power supplies left, even if they are broken, I would be interested in buying one. I did not get in on the auction when they liquidated. What state are you in (if interested)?

author: Soxfan
author_rank: Newbie
timestamp: September 24, 2018, 04:46:38 am
content: That looks pretty good. Thank you. I'm a beginner but not a complete neophyte. I have some knowledge, but its all self taught.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 24, 2018, 12:45:05 pm
content: Quote from: tpowell1830 on September 24, 2018, 04:19:56 amSorry, a bit of an assumption on my part reading between the lines.I am in south Florida. I have a grandson who is just beginning a drones and robotics class in junion high school. I have been stockpiling some inexpensive T&M equipment in case he gets enthused, so at the moment I don't have anything extra. The ITT supply is drying up, but if you are not in a rush ebay still has plenty of good deals come along. I like that PS because Tektronix re-badged the same unit as their CPS250 PS. They are usually very pricey compared to the same unit in BK labeling, but TEK did do a very detailed service manual with parts list and schematics that is sold on ebay in CD format for about $15. Very handy when fixing one of these.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: September 24, 2018, 01:22:41 pm
content: The only thing I'd worry about from hospital salvage is blood. I had a medical monitor I bought surplus and I thought it was fun until I noticed the stain on the front panel, it was obviously blood, unless someone was eating strawberry jam next to a medical monitor.I wanted to burn my whole street down and swim in pure bleach for a week.Never again.Parts are so cheap these days there's no point in "salvaging" 20 year old garbage especially if you tack on the biowarfare "ick" factor.Seriously, the idea that you can somehow save money or time desoldering jelly-bean parts is ludicrous these days.

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 24, 2018, 01:54:09 pm
content: Quote from: In Vacuo Veritas on September 24, 2018, 01:22:41 pmMy wife has 30 plus years as an surgical nurse. Blood and bodily fluids are nothing to be taken lightly, but thoroughly dried blood on a piece of equipment like that is not going to transmit anything. That's just over the top. If it grosses you out, that's a personal thing, but it is not dangerous.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: September 24, 2018, 02:16:01 pm
content: Quote from: Old Printer on September 24, 2018, 01:54:09 pmAppeal to authority is a logical fallacy.https://en.wikipedia.org/wiki/Prion

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2018, 02:48:31 pm
content: Quote from: In Vacuo Veritas on September 24, 2018, 02:16:01 pmPrion diseases are very rare. Nurses tend to know know very well what are actual hazards and what's more of a theoretical hazard. Even a lot of medical equipment is sterilized or cleaned in ways that aren't effective against prions. Not every appeal to authority is a logical fallacy. Sometimes people simply know what they're talking about.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: September 24, 2018, 02:58:21 pm
content: Quote from: Mr. Scram on September 24, 2018, 02:48:31 pmYeah, until it happens. Just like the people who "knew what they were talking about" about ulcers. Can't be bacteria, right? 30 years of "knowledge" obviously said it was "stress". Oops.If there's one field where every claim is suspect, it's medicine.https://en.wikipedia.org/wiki/Helicobacter_pylori"At the time, the conventional thinking was that no bacterium could live in the acid environment of the human stomach"https://en.wikipedia.org/wiki/Barry_MarshallMarshall has been quoted as saying in 1998 that "(e)veryone was against me, but I knew I was right."it was discovered that the lab technicians had been throwing out the cultures after 2 days. This was standard practiceDue to other hospital work, the lab technicians did not have time to immediately throw out the 31st test on the second day, and so it stayed from Thursday through to the Monday. In this sample, they discovered the presence of H. pylori.So you'll excuse my skepticism for the claims of a field where accident seems to play a major role. Medical people really need to get their egos checked, seriously get over yourselves.Besides, we aren't talking about what nurses know or don't know in an operating theater, we are talking about decommissioned medical garbage that has seen thousands of patients. You gonna put your money where your mouth is and lick that dried blood, tough guy?Is it really worth it to salvage stupid 25 cent jelly bean opamps so someone can build a 50$ power supply? Really? Why not use knobs from a Fukushima reactor while you're at it? There's no risk, someone said so! They know what they're talking about! They've been repeating the same crap for decades without checking, I'm convinced!

author: Old Printer
author_rank: Frequent Contributor
timestamp: September 24, 2018, 03:19:03 pm
content: OK, so swim in bleach and burn your street.But if you are ever in an accident you should hope the first responders don't share your view.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2018, 03:26:26 pm
content: Quote from: In Vacuo Veritas on September 24, 2018, 02:58:21 pmNurses quickly find out about actual infection risks if they're wrong about what to worry about. Operating theaters are much more controlled environments than those nurses operate in every day. It's essentially a massive clinical trial on what works and what doesn't. How many nurses have died from prion infection in recent history and how much more exposed are they compared to touching a single device?By the way, belligerence and making a lot of noise is improper conversational etiquette. Making an appeal to extremes is a proper logical fallicy, which both supposing that prion infection is common and referencing Fukushima are. Referencing other cases not relevant to the discussion is a non sequitur fallacy. The ulcer case has nothing to do with how big the risk of prion infection from a random pool of blood actually is. There is a risk so you're technically correct, but the practical risk seems to be so small that even hospital equipment isn't cleaned in ways that would properly eliminate prions.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: September 24, 2018, 03:37:06 pm
content: "Nurses quickly find out about actual infection risks if they're wrong about what to worry about. "How quickly does a prion infection show up?? Ever eat a hamburger in London in 1999? Notice any shaking in your hands lately?"even hospital equipment isn't cleaned in ways that would properly eliminate prions."Exactly, so why risk it for 25 cent parts? Seriously, the mental gymnastics required to justify that are the real fallacy here. Just throw the crap out, buy new parts." belligerence"Facts are belligerence?"making a lot of noise "Ah, you were wrong, so it's "noise". Gotcha.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2018, 04:05:15 pm
content: Quote from: In Vacuo Veritas on September 24, 2018, 03:37:06 pmIf you show us the prion infection rate of nurses is something worrisome I'll eat my words. Although I suspect that if there were any real numbers or facts we would have seen them by now and the noise is to compensate the dented ego.Not that I'm disagreeing with your conclusion about jellybean parts. Even if you don't value your time it makes more sense to use new parts.

author: james_s
author_rank: Super Contributor
timestamp: September 24, 2018, 04:14:46 pm
content: Quote from: In Vacuo Veritas on September 24, 2018, 01:22:41 pmI get blood all over my hands every time I cook steaks, so what? A little months old dried blood won't hurt you. The average clean looking doorknob is swarming with more invisible bacteria and viruses that will actually make you sick than the grossest old medical equipment you're likely to find.

author: Rasz
author_rank: Super Contributor
timestamp: September 24, 2018, 05:42:02 pm
content: Quote from: Soxfan on September 24, 2018, 02:32:16 amah, the good old HOARD, pride and joy of every EE enthusiast ;-)Just make sure you dont go too far and start collecting cot feet like Dave.Quote from: Soxfan on September 24, 2018, 02:32:16 amTake high enough(to read chip designations) res pictures of all of your prized possessions and throw them on a website/imgur album.Quote from: Soxfan on September 24, 2018, 02:32:16 am$1 lm317 is a cheap, good enough starthttps://www.ebay.com/itm/LM317-DC-DC-Buck-Step-Down-Converter-5V-40V-To-1-2V-37V-Linear-Voltage-Regulator/322584903799

author: james_s
author_rank: Super Contributor
timestamp: September 24, 2018, 06:30:37 pm
content: In many cases I think complete equipment or subassemblies are more interesting than salvaged components. Lasers and X-ray equipment are popular hobby items. Personally I'm also interested in displays such as small CRTs, VFD and various unusual stuff.

author: Bashstreet
author_rank: Frequent Contributor
timestamp: September 24, 2018, 07:04:16 pm
content: Quote from: In Vacuo Veritas on September 24, 2018, 03:37:06 pmSolution ?"Responsible people use full body condom"