Have $350US to Spend on a Bench Power Supply - Page 1
Forum section: electronics / beginners

author: thakidd
author_rank: Regular Contributor
timestamp: September 28, 2010, 08:34:38 am
content: First of all, thanks goes out to Dave and the community. I have learned a lot just catching up on the forums and videos!Trying to complete my bench so I can get serious with what I have been up to. Long story short, I have been screwing with C#/C++/VB/PHP and Java for the past 6 years in an IT/devel capacity. When I was a kid 20+ years ago, I started with Radio Shack electronic kits and then moved on to playing with parts my dad brought home from his job. Lost focus for 15 years and then discovered the BS2 > Arduino > Make Controller > and a few embedded Linux boards.I am getting pretty good at prototyping projects but feel I really haven't had quality tools to advance farther. Bought some stupid $120 meter/12v psu/soldering iron combo a year ago and have had no luck what so ever with SMD. Thanks to this forum and Dave's videos, I bit the bullet and purchased the Rigol 1052E (i've needed a scope for 9 months or so) and a Hakko 936-12. I also have an Ideal 61-361 digital multimeter that I purchased a few years ago, drills, drill press, glue gun, dremel, and a panavise circuit board holder...think it does 0 to 10".I see myself primarily tackling digital circuits. I have one more item currently on my list; I need a good PSU. I was reading the forums and noticed a few people said good things about Instek. I have been looking at their GPS-3030DD, GPS-6030D, and my favorite reading the specs, the GPS-2303.Wondered if I could get some feedback on PSUs...Would those models work well and last a while or should I be looking in a different direction. Again the budget for a PSU is topped out at $350US and I do not feel comfortable building my own yet as my bench is in a town home man cave/bedroom.I would also love any additional pointers on any other tools you think I might need for my workbench besides lots of components!Thanks for the help.

author: Bored@Work
author_rank: Super Contributor
timestamp: September 28, 2010, 06:24:29 pm
content: $350 is more than enough for a PSU, especially if you don't want one from big brands like Agilent.In fact, the market is swamped with Made in China PSUs, of OK quality (and of course some dangerous junk). Although prices have gone up a little bit in recent month. These PSUs are usually advertised as "lab grade". Don't take this to serious, they are OK, but "lab grade" is an entirely different game, a game you don't need.The GPS-2303 you mentioned is a dual power supply, isn't it? As an example I randomly picked a typical Chinese power supply from ebayhttp://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370436827930This is a triple one (two adjustable outputs, one fixed), for $162. Don't get confused by the label. PSU's looking like this are all from China and come under hundreds of different "brands". Just order enough of them from the factory, and the factory will put whatever label you want on the front.I can't guarantee that this particular one will last long, and I encourage you to look around. However, these PSUs are usually pretty robust, because they have rather simple technology, and are often build around common regulators that are on the market for decades.My example is at the lower end of the scale, still I regard this PSU as OK. If you spend more you often just get a PSU with a nicer front plate, but the same guts. You can pay more if you change the technology, SMPS instead of linear regulation, remote control, more fine grained adjustments, more precision.

author: slburris
author_rank: Frequent Contributor
timestamp: September 28, 2010, 06:30:31 pm
content: If you are in the US, you might look over some of the Mastech power supplies athttp://www.mastechpowersupply.com/They have been happy to send me schematics of power supplies I've beeninterested in. Have the schematic is important to me, because it gives me adecent chance to repair the supply if something goes wrong. The Mastechones I've looked at are pretty much all off the shelf parts, quite repairable.I have a power supply from Circuit Specialists:http://www.circuitspecialists.com/level.itml/icOid/8613that I got off of Ebay, and I've been quite happy with it as well.Scott

author: KTP
author_rank: Frequent Contributor
timestamp: September 28, 2010, 07:04:02 pm
content: For smt, the single most important tool I have other than my weller iron is a cheap ebay binocular microscope (10x, 30x, 50x). I actually solder while looking through the microscope at 10x, then flip to 30x to inspect the joints (for something like TSSOP38 or TQFP64). A good flux pen and some really thin solder helps too.

author: thakidd
author_rank: Regular Contributor
timestamp: September 29, 2010, 05:52:03 am
content: @KTP: Didn't think about that addition but that completely makes sense. Just out of curiosity, what 'model' did you grab? I do need to up my soldier and flux pen (fat soldier and brush flex here...bad stuff). Anything you recommend soldier size wise and type of pen?@slburris: I was wondering about the Mastech. Why did you go with the Circuit Specialists though?@ BoredAtWork: That makes complete sense. I will look into those. Got to love China...if you are consuming.

author: sonicj
author_rank: Frequent Contributor
timestamp: September 29, 2010, 01:13:51 pm
content: mod a old computer power supply and put the $$$ towards other gear on your wish list. you get 3.3v, 5v & 12v +/- with plenty of amperage. they can be had for cheap or free!-sj

author: KTP
author_rank: Frequent Contributor
timestamp: September 29, 2010, 01:45:12 pm
content: Quote from: thakidd on September 29, 2010, 05:52:03 amJust make sure the microscope is the kind with the large diameter low power objective. I don't know what model mine is...just some China garbage that works.Something like this:http://cgi.ebay.com/NEW-DISSECTING-BINOCULAR-STEREO-MICROSCOPE-10X-30X-/200523954282?pt=LH_DefaultDomain_0&hash=item2eb028b86a

author: TopherTheME
author_rank: Regular Contributor
timestamp: September 29, 2010, 02:03:36 pm
content: Quote from: sonicj on September 29, 2010, 01:13:51 pmI've got a PC power supply on my bench and it works great, especially for amount I paid for it ($0). The -12V and -5V rails really come in handy for powering op-amps.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: September 29, 2010, 04:23:49 pm
content: Just bought this off fleabayhttp://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=190448067151&ssPageName=STRK:MEWAX:ITnot a very good pic but seems a decent unit from what i've read.Picking it up on Saturday.

author: FreeThinker
author_rank: Frequent Contributor
timestamp: October 03, 2010, 10:03:49 pm
content: Quote from: FreeThinker on September 29, 2010, 04:23:49 pmPicked it up Saturday, does what it says on the tin...also got a Isotech ISR650 50mhz scope thrown in for an extra £13.50.Result!!!!. Plugged in and both work okAny one got an operators/service manual? Thanks in advance

author: thakidd
author_rank: Regular Contributor
timestamp: October 04, 2010, 08:15:35 am
content: Thx for all the replies!Manson...that is an interesting choice in name. Glad they worked out for you.I went to Fry's Electronics (haha, great name for a Wal-Mart kind of electronics shop...teehee!) and picked up a MastekHY3003F-3for $150US. Brought it home and immediately hooked it up to the Rigol scope to check it out. So far it seems pretty stable. Broke into it and was disappointed with the design quality. All in all, I cannot complain too much as it has turned out to be a pretty good piece of equipment. I just hope it lasts a while.

author: slburris
author_rank: Frequent Contributor
timestamp: October 04, 2010, 01:36:06 pm
content: Quote from: thakidd on October 04, 2010, 08:15:35 amCan you post some photos of the quality problems?I picked up a Circuit Specialists power supply on Ebay a few months ago, and it's workedjust fine. But if you look inside, there's plenty of evidence of sloppy hand solderingof surface mount components.Scott

author: FreeThinker
author_rank: Frequent Contributor
timestamp: October 04, 2010, 03:09:38 pm
content: Quote from: thakidd on October 04, 2010, 08:15:35 amRebadged by the likes of Rapid,Maplin,RS in the UK but manson is the name under the sticker.May change the pots to 10 turn ones as the selectivity is not great, or may add a second fine tune pot in series but will do fine for now.Not a top of the range unit but more than enough for my needs.Next on my list is a cheap DSO.Off to give Ebay search a good work out

author: Bored@Work
author_rank: Super Contributor
timestamp: October 04, 2010, 06:58:51 pm
content: Quote from: thakidd on October 04, 2010, 08:15:35 amThat's the way they are. Rather simple technology, OK, but not more.

author: Feanor
author_rank: Regular Contributor
timestamp: October 07, 2010, 11:50:25 am
content: Used Mansonhttp://www.altronics.com.au/index.asp?area=item&id=M8226.No complaints at all, opened it up all looks pretty good inside.

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 03:34:05 am
content: Is it worth it to build a power supply using a computer power supply, and using resistor to control the current?

author: MrPlacid
author_rank: Frequent Contributor
timestamp: October 11, 2010, 03:52:06 am
content: Quote from: SuperMiguel on October 11, 2010, 03:34:05 amFrom what I've heard, no. It seemed that people who go this route sooner or later break down and buy a real power supply.

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 04:33:24 am
content: this one any good:http://www.circuitspecialists.com/prod.itml/icOid/10180orhttp://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-regulated-variable-dc-power-supply-hy1503d-15v-3a/prod_64.htmlor i should ask whats the best Power supply i can buy for around $50-$100 ?

author: Bored@Work
author_rank: Super Contributor
timestamp: October 11, 2010, 05:25:13 am
content: Quote from: SuperMiguel on October 11, 2010, 04:33:24 amLet me repeat almost word for word what I wrote before. Maybe you care to read it this time.QuoteQuote from: SuperMiguel on October 11, 2010, 04:33:24 amAsking for "the best" is usually a stupid move. Every piece of equipment is a compromise, usually of many factors. In fact, if you go into a shop and ask for "the best" the shop assistants immediately know they can rip you off, since you haven't clear requirements and can be lied to.

author: saturation
author_rank: Super Contributor
timestamp: October 11, 2010, 02:47:49 pm
content: I have just finished evaluating a Mastech linear power supply. I had to get hold of high power resistors to load it down to maximum and I was surprised it did better than its specification; it also did not blow. I don't have time to post the pics and raw data, but if you're looking for a great linear PSU for under $100, Mastech is very competitive, for this model:Load regulation: maximum load, 3A, 30Vdc, ripple was in the microvoltunder lower voltages it was fairly constant at under 1mV, down to 0.1Vdc, a bit concerning but good, when using it to drive low voltage circuitsDid not test line regulationPower draw quiescent was 8W, at maximum load it drew 140WCONS:The amp meter is quite accurate, the voltmeter is not. This is because it measures Vdc out including the internal resistance drop of the PSU, so under load the voltmeter reading is off as high as 10%.You can recalibrate both meters, it has its own adjustments screws under the meters, and is not mentioned in the manuals. However, the internal resistance wont' change the accuracy of the voltmeter.The voltmeter is non-linear, and even with zero load there is a 1-0.5% error reading 0-30V.The voltmeter is most accurate the lower the loads are. its not a problem driving modern circuit designs that draw in the mA, but if you're near 1A, its best to get a separate DMM to monitor the supply.The fan is always on. Its unnecessary under 1A loads, but it would be best if it had a small thermal cutoff switch since it is noisy. It is definitely needed once 1A loads are used, and the unit starts to get hot internally.See discussion here:https://www.eevblog.com/forum/index.php?topic=683.15My unit:The Hi/Lo switch doubles the current output for the current current knob setting. A strange switch but the main advantage is that the total power consumption of the whole PSU is lower slightly if this switch is LO for the same output volt-amps, in other words if you output 1A at 30V with this switch at LO, the power consumption is lower that if you switch it to HI and still output 1A, 30V.So default, leave it at LO until the amps provided are no longer sufficient.The fine adjustment is terrific! You can adjust millivolts and milliamps with easy stable precision.The lowest price Mastech is $50, its a steal.Quote from: slburris on September 28, 2010, 06:30:31 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 02:57:14 pm
content: is 3A enough?

author: saturation
author_rank: Super Contributor
timestamp: October 11, 2010, 03:18:57 pm
content: For electronics work, yes. Most electronics today are very low power devices and driving voltages are far under 10V, they are often designed to work with just batteries or brick supplies. A typical cellphone battery is 1500mAH at 3.7V, so at full power this unit can supply 1.5A at 3.7V for only 1 hour, far within the capacity of the cheapest Mastech supply.A common use for high current are in radio transmissions or audio amps, but digital has reduced power consumption markedly compared to analog radio. As for designing audio amps, well, sky's the limit!What is more common to use today for general electronics are multiple supplies, that is having 2-5 PSU variable supplies. I typically use 2 at one time, one to power the project, another to provide variable input. Once I've tested it with variable DC, then I switch to a function generator. Thus, you often find dual supplies built into one unit.2 Mastech 15V supplies will cost you $100, plus s&H, far under your budget. If you're just starting, just get one to check it out, you'll always have a need for just 1 variable PSU.A minimum voltage to have is about 15V, this is typical for driving analog op amps, usually 10V and up. Since op amp supplies are often split, such as 15V and -15V, 2 15V supplies can power such circuits easily. These are typically uses for dual tracking supplies, which roughly cost about the same as 2 single units.Many folks opt to get single PSU with dual/triple/quad supplies built into one unit, but I prefer to buy them separate. If the unit fails, you lose all those multiple supplies simultaneously, and if you check the cost, its near the same to buy separate Mastech than a single multi-supply.Programmable or computer controlled supplies are rarely needed for home or individual use. They are very useful in production work, when even the time to twiddle knobs takes too long, and you want to dial in a precise A or V, or have it controlled to do multiple QC tests on a production line.Quote from: SuperMiguel on October 11, 2010, 02:57:14 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 03:40:55 pm
content: this one :http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-regulated-variable-dc-power-supply-hy1503d-15v-3a/prod_64.html

author: saturation
author_rank: Super Contributor
timestamp: October 11, 2010, 04:23:01 pm
content: Quote from: SuperMiguel on October 11, 2010, 03:40:55 pmhttp://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/mastech-regulated-variable-dc-power-supply-hy1503d-15v-3a/prod_64.htmlIf you do want one, email Sean and get CONFIRMATION BEFORE you order on the ff:The unit is in stockWhen will it shipFinalize the priceThe website automated ordering system works, but the stock and final price maybe different. Sean will answer email about orders very quickly.

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 04:30:59 pm
content: Whos sean? Whats his email?wow shipping is $20so the final price on the site is $69.99 with shippingalso does this power supply ship with the probes?

author: saturation
author_rank: Super Contributor
timestamp: October 11, 2010, 05:12:08 pm
content: Sean is the owner of the business and the sysop.http://www.mastechpowersupply.com/contact-us/info_2.htmlS/H price will vary, so speak to him via email. The reason for the price is the power supplies are heavy, at least #10.No probes.Quote from: SuperMiguel on October 11, 2010, 04:30:59 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 05:21:08 pm
content: Quote from: saturation on October 11, 2010, 05:12:08 pmk email sent, also where do i get the probes for this specific unit?

author: saturation
author_rank: Super Contributor
timestamp: October 11, 2010, 06:35:50 pm
content: They have them for sale also on the same site, and it probably will not have any more added S&H. Mostly commonly used are banana to alligators. Split ring or ring connector to alligators also work.I buy them in bulk from eBay for $1 each or less, I think the Mastech site charges $5-10 each but they are already pre-selected for maximum amperage. If you know how to buy wire sizes for current capacity, generic eBay cables work, if not stick to Mastech. Power cables are very low tech.Quote from: SuperMiguel on October 11, 2010, 05:21:08 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 11, 2010, 07:45:53 pm
content: just ordered should ship tomorrow

author: saturation
author_rank: Super Contributor
timestamp: October 11, 2010, 08:21:19 pm
content: Awesome, please review it for us when you get it, from the ordering process from Mastech to the product you get. Hope you enjoy it.Quote from: SuperMiguel on October 11, 2010, 07:45:53 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 14, 2010, 10:00:23 pm
content: I should get this psu on monday, now because it is only 3 amps, should I build a bench power supply from an atx psu in case I need higher amps? Is it worth it?

author: saturation
author_rank: Super Contributor
timestamp: October 15, 2010, 08:01:10 pm
content: I've not yet had a reason to use 1A on a continuous basis other than doing checks on power resistors. I typically work in the 500mA +/- 250mA.Quote from: SuperMiguel on October 14, 2010, 10:00:23 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 18, 2010, 08:00:13 pm
content: So i got the Mastech HY1503D and welll wellI got the unit on friday.. Opened the box, and when i plug the probes the probe's holder slide back, opened the case and found out that the board that goes behind the probes holder was broken (see picture) at that moment i sent an email to Sean (i guess the owner of mastech) he didnt reply... I called him, and he said " im not at the office right now" ok...Saturday passed, sunday night, i see Sean connected in gmail chat, i asked him again on what we can do... He sent me an email, with an address for me to send the item back (the psu is heavy and costed $40, shipping back of it would be about $30) i got a bit mad and asked him for a return shipping label... he said "im going to file a complain with fedex so they can pick it up" so i say "so you are going to send me the replacement one tomorrow while i wait for the fedex guy?" he said NO when we get the defective unit ill send you the replacement one.... all i said was wow (so i waited 5 days for this to get from CA to FL, so 5 days to go back to him, and 5 more to go back to me15 days nice!) .. great customer service... so i asked when will fedex come pick this up? he disconected...Today i sent him an email early on the morning asking the same thing... no answer.. I sent another email around noon time.. and no answer..Great customer serviceill update back when i know somethinghttps://www.eevblog.com/forum/index.php?action=dlattach;topic=1378.0;attach=4060;image

author: saturation
author_rank: Super Contributor
timestamp: October 18, 2010, 08:22:23 pm
content: I can't see your photo very well but after resizing it and fixing the gamma, it looks like the PCB here is fractured, see arrow.Sorry to see this and hear of your hassles. Generally, I would repair this myself rather than ship it back, because the unit is low cost and the shipping is expensive. But you need to do what you need to do.

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 18, 2010, 08:26:11 pm
content: im sure i can fix it too.. i just hate to fix something that is brand new...

author: MrPlacid
author_rank: Frequent Contributor
timestamp: October 18, 2010, 08:34:49 pm
content: Just to be fair, it's ok for the seller to wait until your package is received to ship you a replacement. You shouldn't take this out on the seller as it is the wise move.

author: Zyvek
author_rank: Regular Contributor
timestamp: October 18, 2010, 08:39:21 pm
content: It would have been nice for the seller to offer send out another order to be credited back when the bad one was returned.

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 18, 2010, 11:18:46 pm
content: Quote from: MrPlacid on October 18, 2010, 08:34:49 pmAgree but, the part that is not fair IMO is that he said that he was going to file the claim with fedex for them to come pick the box up... I have sent multiple emails to the seller and no answer... So as right now i dont know if that claim will take 1-2 days or 15-30 days....

author: saturation
author_rank: Super Contributor
timestamp: October 19, 2010, 12:44:27 pm
content: Yes, I agree, but consider find any other vendor that can sell the same or similar for the price you bought it and whether you can get the service you are looking for. Its not an excuse for Mastech business action, but cheap comes with its downside.When I buy electronics from eBay, many from China, I can pay $2 each, shipping and handling included, even as high as $10, but its impossible for me to ship back and recoup my costs if the device is a dud.Even big ticket items like power supplies and meters, I bought recently one for $10 that cost $30 to ship that can generate 3kV, it just isn't worth shipping back, new or old.One thing to can try is call Fedex and ask for what to do with damage goods what one can say is due to their shipping, see what they say and how long it will take. You can also let Mastech know you are reviewing his performance on a forum, and he knows what that can mean to future sales.Quote from: SuperMiguel on October 18, 2010, 08:26:11 pm

author: slburris
author_rank: Frequent Contributor
timestamp: October 19, 2010, 02:00:19 pm
content: Been doing a little research about mastechpowersupply.com....It looks like it's really acifica.com which sells motorcycle trunks,hard saddlebags, and Mastech power supplies. What acombination!They also runhttp://www.rigoloscilloscope.com/and say theyare an authorized Rigol distributor. Checked out the Rigol functiongenerators and each and every model says in stock Qty 20. Somaybe the stock level isn't quite accurate as a previous postersuggested.I'm guessing it's a one person operation importing the Mastechgear? Certainly if you look up the contact address, you get a housein San Jose :-)I haven't bought from them, but have made some email inquiries aboutschematics which were answered promptly by Sean.Scott

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 19, 2010, 02:20:26 pm
content: never got an email from sean, but saw him last night in gmail chat, and asked him one more time, he told me that he filled the claim with fedex, i asked when they will pick up the package and he said that he didnt know that it takes few days... i asked if there was a way to find the exact day, he said no... So i guess ill just wait until fedex decides to come to my house...

author: Bored@Work
author_rank: Super Contributor
timestamp: October 19, 2010, 04:59:35 pm
content: Don't wait until Fedex makes a move. All carriers have a deadline until you have to report damaged goods. Make sure that deadline doesn't expire while you wait for something, something that might never happen, because someone forgot to ...

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 19, 2010, 06:02:56 pm
content: Quote from: BoredAtWork on October 19, 2010, 04:59:35 pmCalled fedex, and they told me that there was a claim but no pick up appointment, so i made the appointment, they told me that the box will be picked up tomorrow, then delivered to a check location, where will be 2-5 days, then it will be sent to the sender via ground.. Wootmore days

author: saturation
author_rank: Super Contributor
timestamp: October 19, 2010, 10:55:49 pm
content: This is good to hear; if you don't have to pay shipping, it's worth exchanging.Quote from: SuperMiguel on October 19, 2010, 06:02:56 pm

author: saturation
author_rank: Super Contributor
timestamp: October 19, 2010, 10:59:57 pm
content: You can read more about my experiences and who Sean is on my thread here:https://www.eevblog.com/forum/index.php?topic=686.msg9661#msg9661It includes the other stores in eBay, reviews of his responses to problems with folks at RC Groups, and others. If you get the address of the store, you can google it and get a picture of a house in a neighborhood in CA. It includes slburris many good comments and queries too.Quote from: slburris on October 19, 2010, 02:00:19 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 20, 2010, 01:20:34 pm
content: fedex just came and picked the package.. lets see how long it takes to get the replacement back

author: saturation
author_rank: Super Contributor
timestamp: October 20, 2010, 06:01:13 pm
content: This is great news. Hopefully it will have a happy ending, and you'll have a fixed new PSU.Aside from the break, what did you think of the rest of the unit's build quality?You are doing well for a newbie, a great scope, and a free exchange on S&H, so hopefully it all works out well in the end.Quote from: SuperMiguel on October 20, 2010, 01:20:34 pm

author: SuperMiguel
author_rank: Regular Contributor
timestamp: October 20, 2010, 07:06:33 pm
content: Quote from: saturation on October 20, 2010, 06:01:13 pmthe unit was very good looking but didnt actually play with it... i saw it broken and boxed it back. so hopefully soon i can review it better it better

author: Ronnie
author_rank: Regular Contributor
timestamp: January 25, 2011, 03:24:15 am
content: Is the replacement unit in good working condition?

author: SuperMiguel
author_rank: Regular Contributor
timestamp: February 01, 2011, 03:34:31 am
content: Quote from: Ronnie on January 25, 2011, 03:24:15 amit was