power supply shopping - Page 1
Forum section: electronics / testgear

author: timelessbeing
author_rank: Frequent Contributor
timestamp: May 08, 2014, 03:57:26 pm
content: In a few days, I'll be going to look at an Agilent U8002A for sale. It is a 30V, 5A adjustable power supply. It is Agilent's economy line, so no bells and whistles, which is fine with me. It retails for around $415 USD. According to the seller, it has never been used and still has the original box. I've never bought test gear before, so I was hoping to get some tips. What to examine, what to consider when negotiating, traps for young players etc. Also, what is a good starting offer? Cheers.

author: Chipset
author_rank: Contributor
timestamp: May 08, 2014, 05:25:52 pm
content: I would honestly say for low range lab power supplies you're better off buying old and used.The feature set for low end power supplies has been pretty much constant for the past forever and a half. On a modern lab supply versus a 10-20 year old lab supply you might get a couple more amps maximum and maybe an output on/off switch. You have to ask yourself if it's really worth it, $100 gets you a decent used lab power supply, $200 gets you a good one.Even though you're buying this second hand it's pretty much like buying new, except you don't get the warranty. Buying test gear new is rarely a good idea for hobbyists, you pay a massive premium for a cal sticker and a warranty that is of very little practical use.My advice is find someone selling an old used lab supply and save some of that money.Or, since you say you've never bought test gear before I assume you're a beginner. Build your own! It'll most likely be crap but you will learn a ton.But if you really wanna go through with this;Ask to take it out of the box and power it on, bring a voltmeter if you can and check it's actually outputting something. If he/she refuses and/or tries to assure you it's fine, something wrong and you should walk away.Check the corners for damage indicating it's been dropped or something like that.And as always when buying used, ask the person face to face why he/she's selling it. If their answer feels disingenuous or outright false, walk away. It's probably stolen or has hidden faults.As for price, $300-$350 maybe?

author: timelessbeing
author_rank: Frequent Contributor
timestamp: May 08, 2014, 08:34:19 pm
content: Thanks for the tips. I am an amateur with some basic needs, but not planning to become an EE, so I need a useful instrument, not a learning project or piece of crap to spend time on. There's nothing good for $100 out there. Not with decent power, digital voltage and current readouts, constant current mode, and current limiting.I will bring a DMM and perhaps a halogen lamp to test with.

author: Shock
author_rank: Super Contributor
timestamp: May 08, 2014, 10:33:35 pm
content: If your looking to bargain it pays to learn how before you turn up.But $200-$300 would be a reasonable price to pay if it was in perfect condition and your satisfied it's what you want.Some would offer less or more dependent if it still had calibration and full valid (transferable) warranty.Let us know what happens.

author: XOIIO
author_rank: Super Contributor
timestamp: May 08, 2014, 10:52:58 pm
content: $415 is economy?I wouldn't pay that full price for that one honestly.