Extech 382270 High Precision Quad Output DC Power Supply - Review - Page 1
Forum section: electronics / general

author: midnight
author_rank: Newbie
timestamp: July 14, 2011, 06:27:22 pm
content: I just posted my quick review of the Extech 382270 Quad Output DC Power Supply:http://youtu.be/syAhzxwmQwQI did not go into the specs... as you can read them right off the manufactures web site. But I focused on usability and impression.To sum it up:Pros:- 4 Outputs- Small footprint- Large meter display- Good power on (no overshoot).Cons:- Output On/Off turns off the meters (so you can NOT see to adjust the output unless it's live).- PCB mounted pots.- Loud fan that is not speed controlled (only on or off).- Selection indicator for V/A meter displays is not intuitive.- DID I MENTION THAT THE OUTPUT ON/OFF SWITCH TURNS OFF THE METERS TOO?I returned this unit in exchange for an Instek SPD-3606. Review of this will come shortly.

author: ciccio
author_rank: Frequent Contributor
timestamp: July 14, 2011, 07:42:04 pm
content: Will somebody on the board explain me the reason for switching the display off?I've been thinking about this for some time, and cannot find any reason...If I was the designer, I've maybe forced the display to blink when the output is switched off, but who knows..Regards

author: midnight
author_rank: Newbie
timestamp: July 14, 2011, 07:57:40 pm
content: Quote from: ciccio on July 14, 2011, 07:42:04 pmI don't know why anyone with common sense who would design it that way... The Instek SPD-3606 does it correctly. With the 3606 when you turn the output off, the meters show the voltage and current limit values for adjustment purposes... then when you turn the output on they show the live values.

author: Ronnie
author_rank: Regular Contributor
timestamp: July 15, 2011, 12:54:12 am
content: Quote from: midnight on July 14, 2011, 06:27:22 pmI returned two units because they are defectiveand replaced with a Protek 3205L instead.http://www.protektest.com/ProdInfo.asp?prodId=3205L

author: saturation
author_rank: Super Contributor
timestamp: July 16, 2011, 02:19:59 pm
content: Great review! Thanks for making it. I prefer multiple simply low cost analog supplies rather than buying an all in one box; if one of those outputs fail for whatever reason, it can take all the other 3 too. But if all were independent stand alone supplies, they are isolated from each other ... if outputs truly float you can easily series or parallel them for more voltage or current, respectively, 4x $50 = $200 supplies can easily exceed the power output of this $400 Extech for half the price. If you buy all identical units, they are easily stacked, but still not as small since they have 4 independent transformers. It lacks the convenience features of the Extech but it also has less in it that can go wrong.

author: ivan747
author_rank: Super Contributor
timestamp: July 18, 2011, 05:44:28 am
content: Quote from: saturation on July 16, 2011, 02:19:59 pmI am in a quest for finding a $50 power supply. Where can I find that model you have there? I hope it's not too heavy. International shipping is a huge pain in the wallet.

author: Freighternut
author_rank: Regular Contributor
timestamp: July 18, 2011, 06:49:33 am
content: Many thanks for the review.Very much looking forward to the review of the Instek power supply. I have been considering these for a while now and you review should help me make up my mind.Thanks again.

author: saturation
author_rank: Super Contributor
timestamp: July 18, 2011, 11:46:28 am
content: The parent of many 'clones' that look like this is Mastech, there are some reviews of it on eevblog:http://www.mastechpowersupply.com/variable-power-supply/linear-power-supply/cat_6.htmlBecause the transformer is heavy, the big expense is shipping; choose the cheapest you get get.There are also many reviews in the RCgroups forum, where they abuse it, and it take a beating well. These reviews go back a few years, but the basic analog models have not changed much.Quote from: ivan747 on July 18, 2011, 05:44:28 am

author: cybergibbons
author_rank: Frequent Contributor
timestamp: July 18, 2011, 03:03:43 pm
content: Quote from: midnight on July 14, 2011, 07:57:40 pmThat's a switcher, not a linear supply no?

author: midnight
author_rank: Newbie
timestamp: July 18, 2011, 03:42:25 pm
content: Quote from: cybergibbons on July 18, 2011, 03:03:43 pmYes it is. My upper limit needs are 10+ Amps at 5v. I really wanted; a small footprint, quick to set up, a real "go to" power supply. Space and setup time are very high on my priority list. I thought I could get away with the cheaper Extech, but wound up with the SPD-3606. So far I am really impressed, but as always.. there is a price for quality.

author: slburris
author_rank: Frequent Contributor
timestamp: July 18, 2011, 06:50:20 pm
content: Great review! Looks like the price is about $450.For $384, you could buy two of these:http://www.circuitspecialists.com/bench-power-supply-csi5505s.htmland not have the same kind of display goofiness. But it wouldtake up a lot more room. I have the 3amp version of this supplyand it is a relabeled Atten supply.Scott

author: slburris
author_rank: Frequent Contributor
timestamp: July 18, 2011, 06:58:57 pm
content: The Quad output supply I've always wanted was the Hameg 7044:http://www.hameg.com/163.0.html?L=0Unfortunately it's been discontinued (and was out of my price range anyway),in favor of the HMP4040, which is similar but uses an LCD display instead of LEDs.I find LEDs to be much more readable at any angle, and color coding the voltagevs. current is a real plus in my book (a plus for this Extech unit).Scott

author: jahonen
author_rank: Super Contributor
timestamp: July 18, 2011, 07:01:07 pm
content: Quote from: midnight on July 18, 2011, 03:42:25 pmI also have the Instek SPD-3606. I can tell you a little story about it.I have been quite satisfied (but there are some quirks, like output on/off seems to be really EMI-sensitive) with it but some time ago, other channel started to act strangely, the display didn't start up until after a while. I opened the thing and I confirmed my suspicions, I discovered a bulged 1000u 16V electrolytic cap (CapXon). I then decided to change all electrolytic caps to something else before something really bad happens due to CapXons. It took me couple of evenings to replace them all, but now it works just fine. BTW, I was able to dig out thedatasheetfor capacitor in question, and based on the specs, it should not happened, as the lifetime spec is 5000 hours @ 105°C.I wonder if the cap was really bad, or then other thought was that maybe it was actually not CapXon but some bad copy of it.Regards,Janne

author: RyanS
author_rank: Newbie
timestamp: October 02, 2011, 09:42:04 am
content: I wonder whether similar models as this under the 'Caltek' brand have the same issue with the display on/off button?The dual 5A:http://au.element14.com/caltek/psm2-5a/psu-laboratory/dp/1270465Or the triple 2A:http://au.element14.com/caltek/psm3-2a/psu-laboratory/dp/1270466

author: DaveW
author_rank: Frequent Contributor
timestamp: October 02, 2011, 10:28:19 pm
content: Quote from: RyanS on October 02, 2011, 09:42:04 amThey do have the same problem, shall have to poke around inside once projects are finished, this seems like it's screaming for a mod to fix the voltage reading, if not the current display...

author: RyanS
author_rank: Newbie
timestamp: October 04, 2011, 07:09:20 am
content: Have you found it to be a problem to use without proper on/off functionality, or more just an inconvenience ?

author: rstoer
author_rank: Regular Contributor
timestamp: October 19, 2013, 10:34:43 pm
content: I just thought I give a heads-up to anyone (especially in the US) considering one of these supplies. There's a guy on eBay selling them in used but excellent condition for $129.00 with reasonable shipping. His listing still says more than 10 available.I found it really hard to pass up at that price. Mine came in the original box with the manual and all accessories. It had obviously been opened but was in great shape and works fine. Let me add that I don't know him (or her) and I'm getting nothing for this. It just seems like a real bargain. Here's the link:http://www.ebay.com/itm/400586119934?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649I also agree fully with midnight's review. In my opinion it's core functionality is fine. The output is stable, there are no surprise spikes upon (soft) turn on/off, and it seems reasonably well built. But it's let down by the poorly designed user interface. It needs at least a 3 turn or coarse/fine control for the voltage, but has neither. Because of that it's very difficult to set precisely. The secondary (8V) supplies and the current are somewhat better for although they share similar 300 degree controls, they only go from 0-8 and 0-5 respectively. Trying to select 0-32 in the same arc is much trickier. I also miss the ability to adjust (or even see) the voltage and current with the output turned off. And there's no memory presets or programmability. In short, there's no way I'd pay $400-450 for this supply, but at $144 delivered it's a no-brainer.