Advice on cheap Lab Supply 30v 5amps seen all the stuff on ebay best quality? - Page 1
Forum section: electronics / testgear

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 02:31:21 am
content: hi guys just wanted to know if you can help me a bit on which Lab supply unit to buy in 30v 5amps I've seen a couple supplies on ebay , but then I checked reviews and one or another ppl say they're shitty. honestly I was looking in 100U$s range. What should be a priority construction wise Transformers, Capacitors inside? fets? I'm like in the middle of nowhere with all these chinese units.Do all these ones have overprotection. And do they adjust amperage accordingly with the device it's being connected ? or I do have to set current, and if it exceeds it says overload?-http://www.ebay.com/itm/ATTEN-PROGRAMMABLE-PRECISION-VARIABLE-30V-5A-DC-POWER-SUPPLY-DIGITAL-LAB-GRADE-/181237126136?pt=LH_DefaultDomain_0&hash=item2a329313f8-http://www.ebay.com/itm/ATTEN-Variable-DC-Power-Supply-APS3005S-30V-5A-LAB-/160684423343?pt=LH_DefaultDomain_0&hash=item256989b8af-http://www.ebay.com/itm/MASTECH-HY3005D-DC-Power-Supply-Lab-Grade-Precision-Adjustable-30V-5A-Backlit-/330939884523?pt=LH_DefaultDomain_0&hash=item4d0d8de3ebTNX!-

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 03:05:19 am
content: I bought one of these a couple weeks ago, build quality seems ok but in all honesty ask me in 6 months.http://www.ebay.ca/itm/Hantek-Programmable-High-Precision-Lab-Bench-DC-Power-Supply-PPS2116A-/221265590812?pt=LH_DefaultDomain_0&hash=item338474fa1cThe big issue with ebay stuff is you never know what you are going to get so a bit of a gamble. In this case I went for it because I need a spare (fast) so this looked like a good gamble. So far so good.

author: Pasky
author_rank: Regular Contributor
timestamp: February 08, 2014, 03:24:49 am
content: http://www.circuitspecialists.com/bench-power-supply-csi530s.htmlSomeone did a tear down of their 3A model and it turned out to be pretty good for the price.

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 03:26:28 am
content: Hey thanks seems a nice supply that one.. but the only way to know if it's good it's to make a tear down and see the inside caps and so on. What are you using it for ? did you make any load tests? Fan noise ? does it have a passive heatsink on the back.How long did it take to arrive.I was looking at here .https://www.circuitspecialists.com/bench-top-power-suppliesany advice?

author: Pasky
author_rank: Regular Contributor
timestamp: February 08, 2014, 03:27:58 am
content: I don't own it, but I have been eyeing it for a couple weeks.

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 03:28:20 am
content: Quote from: Pasky on February 08, 2014, 03:24:49 amThanks seems nice that one , kind of solid. But I'm looking something with overload protection and a couple more functions. Like enable output or disable. short protection etc.

author: Pasky
author_rank: Regular Contributor
timestamp: February 08, 2014, 03:29:28 am
content: The more you want, the more you need to pay.

author: nanofrog
author_rank: Super Contributor
timestamp: February 08, 2014, 03:32:23 am
content: Between Atten and Mastech, Mastech has a better reputation.That said however, would you have an issue buying a used PSU?I ask, as you can get some excellent supplies, such as a well built triple output unit within your budget. One example I found, would be aPower Designs TP343A. It can't quite do 30V@5A, but it gets close (up to 5A @ 20V / 2A @ 25V / 1A @ 50V when the upper two supplies are tied together via tracking mode). Then there's the third supply at the bottom (0-6V @5A, or 0-15V@2.5A). Also has current limiting (set by the flat blade screws). A lot of PSU for the money, and worth considering IMHO.Just a thought anyway.

author: rdl
author_rank: Super Contributor
timestamp: February 08, 2014, 03:36:10 am
content: Do they still make that Korad KA3005P?

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 04:06:19 am
content: hmm I've heard some bad things about the korad.. having issues .. and so on . What would be a good choice from all these from the list 100 bucks range 30volts 5Amps or more (overload protectin short circuit as well)https://www.circuitspecialists.com/bench-top-power-supplies

author: jwm
author_rank: Regular Contributor
timestamp: February 08, 2014, 04:24:24 am
content: I have had the MASTECH one for a while, It works just fine but I have some issues with the interface.The separate fine/course knobs are fairly annoying, you find yourself jumping back and forth between them and it's easy to mess up. I would have prefered a single knob.The displays always show whatever current/voltage is currently going through your device, so there is no good way to actually set specific limits on current/voltage without diddling with the knobs live, or beforehand with an open circuit for voltage and across a load for current. Plus I'd like an easy way to turn on and off the channel.And one more random nit, the protective plastic was left over the lcd screens and was all bubbly. I had to disassemble the thing to get it out, everything seemed fine inside, but QA issues like that worry me a little.Do models such as the hantekhttp://www.ebay.com/itm/Hantek-Programmable-High-Precision-Lab-Bench-DC-Power-Supply-PPS2116A-/221265590812or attenhttp://www.ebay.com/itm/ATTEN-PROGRAMMABLE-PRECISION-VARIABLE-30V-5A-DC-POWER-SUPPLY-DIGITAL-LAB-GRADE-/181237126136fix this?Anyone know a cheap triple supply that has the ability to independently see the max voltage/current independently of the actual instantanious voltage/current?

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 04:46:39 am
content: Quote from: jwm on February 08, 2014, 04:24:24 amThat's the one I was also taking into account the atten supply. Is it good?. So the mastech HY3005D doesn't work quite well..do these lab supplies provide amperage to the device it's drawing towards it.. automatically? or you have to set up the current and if the device draws way more amperage than what you have setted it overprotects?

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 04:53:48 am
content: With the Hantek you can adjust voltage and current on the fly and before hookup without shorting the supply to set the current. It has an output on off switch. It also has overcurrent and overvoltage protection.Main faults, electrolytics are not brand name so need replacing. Knob on case is not the best quality.Pluses, very nice looking transformer, fan is temp controlled, case is very heavy gauge steel, grounding and soldering are good.

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 05:15:10 am
content: Quote from: pickle9000 on February 08, 2014, 04:53:48 amhey that's a really nice built and assembled supply from what I could see . But again I don't understand the following. Say I connect a device to the supply requiring 5amps and 5volts. If I set 5 volts on the supply and it starts requiring more than 5amps what's going to happen it overprotects? Or It starts auto adjusting the extra amperage required.Something else do you know if these units ship from Canada to the US through USPS ? Can you post me another supply as well but from the us itself. Tnx!

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 05:38:45 am
content: If your device tries to draw more current than what the supply is set for (lets say 1 amp) one of two things will happen. This again depends on the settings. First, in current limiting mode the supply will limit the draw to 1 amp. Overcurrent protection is a setting that act like a circuit breaker and turns disconnects the output.In the case of 5 amps the supply would limit the output to 5 amps because that is the maximum is can supply. Overcurrent is a separate setting and need not apply.In a real life situation let's say you are testing a new circuit and you think it needs 200ma at 5 volts. You set your supply to say 240ma at 5 volts and the overcurrent protection for 300ma. You turn on the power and instantly it goes into overcurrent protection and the power is shut off. You have a problem, time to check the board and look for a short or other issue. If you had the current set to 5 amps and no overcurrent protection you would probably see some magic smoke.

author: dssence
author_rank: Regular Contributor
timestamp: February 08, 2014, 07:04:22 am
content: Quote from: pickle9000 on February 08, 2014, 05:38:45 amI see ,so if I had a device drawing say 500ma 5volts, and I set the supply to 5volts ..then current to 600ma. and overcurrent protection at 700ma and the device draws 800ma , supply will protect itself cause I have setted overcurrent to 700ma?

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 07:08:26 am
content: Exactly.

author: grumpydoc
author_rank: Super Contributor
timestamp: February 08, 2014, 08:54:35 am
content: QuoteIf you want the over-current protection to turn the supply off and protect your prototype from design or implementation cock-ups you need to set the overcurrent level lower than the current limit. Otherwise the voltage will collapse a bit but you'll still put 240mA (in this example) into your design - which might not be healthy for it.

author: jwm
author_rank: Regular Contributor
timestamp: February 08, 2014, 10:36:45 am
content: Erf... I tried to read the manual of the Hantek one to figure out how it's max current/voltage interface works. this is what I found.Open the power switch, set the voltage, press the VOL voltage adjust selection key, shows the digital voltage regulator tube is selected, the selected digital tube status in the flickering, spinning move ADJUST switch, variable voltage value of the size, again press the VOL voltage adjust selection keys can be selected to change the location of digital tube.I guess the audiophiles will appreciate that there are not just tubes, but digital tubes!

author: mrflibble
author_rank: Super Contributor
timestamp: February 08, 2014, 11:07:54 am
content: curious. tube is chinglish for segment display or something?

author: rdl
author_rank: Super Contributor
timestamp: February 08, 2014, 01:45:47 pm
content: QuoteSeems that way. They often refer to 7 segment LEDs as "digital tube display", very common to see this on eBay.

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 07:25:40 pm
content: It takes about 60 seconds to learn how to operate, similar to Japanese style temp controllers. One handed operation.Actual interface operation is fast, no complaints.Interface Operation InstructionsHantek PPS2116A Power SupplyIndicators- A single flashing 7 segment digit indicates you are in set/adjust mode for that item (current or voltage adjust).- M1-M6 are the memory storage indicatorsSet knob / wheel- When in set/adjust mode (single flashing digit) you can increase/decrease the set point. For example if 0.100 is displayed and the 1 is flashing you can adjust by .1 volts (up or down to the maximum or minimum voltage). One rotation of the knob is about 10 steps so in this case 1 rotation is about 1 volt.VOL/CUR buttons- Push once to enter set mode, push repeatedly to change the digit adjust position (1v,1/10th a and so on) then use the knob to adjust. I like to adjust by 1/10th of a volt so I leave it there. Same for current.SHIFT- Push SHIFT before M1-M5 to store settings.- Push SHIFT before Output for overvoltage overcurrent store.M1-M5- Load stored settings.OUTPUT- Turn output on/off

author: Pasky
author_rank: Regular Contributor
timestamp: February 08, 2014, 07:42:43 pm
content: So is the general consensus here that the Hantek is the best linear power supply for the price at < $100? I've been in need of a 3A-5A DC power supply and not sure what to get myself.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 08, 2014, 08:16:13 pm
content: I've been sort of looking for a power supply and I read this thread. I don't see any consensus here. But I know I will not get one of these Hantek or Atten or Other re-badged supplies. It seems more risky to buy a new one of these then a used, known brand on ebay. I've noticed that Dave has a Rigol dp832 but that has a serious issue that Rigol has ignored fixing (and a different price range). He also has a BK on his bench. You can check his ebay store (or amazon?) and see what stuff he sells off it might be a indicator of what he considers a keeper.ebay has thousands of PS listed, you can filter by location in miles to keep shipping cost down.

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 08:29:52 pm
content: The Hantek:The price is actually about 120 bucks shipping included (in Canada). If you expect to add 10-15 bucks to get a few good electrolytics you are at 135 bucks (CDN). It does have optically isolated usb control as well.Will it last? I can't say time will tell, is it worth the money? Yes. Does it beat the other 100.00 chinese specials? For sure.If you compare this to the Atten in the first post shipping in cost makes it 165.00 It does have a serial connection on it, requires install by the user, don't know about isolation. It beats it by virtue of the usb connection.Will I recommend it? No, I think it's worth the money but that's as far as I will go.

author: rdl
author_rank: Super Contributor
timestamp: February 08, 2014, 08:39:08 pm
content: I don't know which came first, the Korad or the Hantek, but they look to be almost identical feature-wise. The Korad without the serial interface is about $110 USD and with the serial interface about $125 USD. The Hantek seems to somewhat of an unknown quantity, not a lot of reviews or teardowns, whereas the Korad has been thoroughly gone over. After seeing the newer revision Korad thoroughly abused and surviving in the video I linked back in reply #8, I think I'd be more inclined to buy one of those.

author: London Lad
author_rank: Regular Contributor
timestamp: February 08, 2014, 08:48:33 pm
content: I use a number of old Farnell bench PSU's and they are 100% reliable and very well built, they often come up on ebay at less than the China ones.

author: commongrounder
author_rank: Frequent Contributor
timestamp: February 08, 2014, 09:21:28 pm
content: Just to add my 2-cents worth, I own the Korad (latest version, triple output, no PC interface) and it has been working solidly. It takes a little getting used to the way the controls work, but once you have a feel for them it is straight-forward to set up and use. The only concern I have is there is a tiny bit of overshoot when switching on the output, but there are a few of us on the trail of a solution, and I haven't had a problem in practical use, so I'm not sweating it. My suggestion with any of these is to take a peek inside after you unpack it and before you power it up the first time, to be sure all is well with the wiring and screws.

author: pickle9000
author_rank: Super Contributor
timestamp: February 08, 2014, 11:03:39 pm
content: I just had a look at Daves Korad vid, man it really died.The Hantek has an identical interface, that said I have seen similar in Japanese temp controllers so no big deal there. If it's not made by Korad certainly it was influenced by it or the other way round.As for the build quality, if what Dave had on the video is representative then the Hantek is way better.Here is a board pic, the board is clean and well soldered. The rest are similar.

author: pickle9000
author_rank: Super Contributor
timestamp: February 09, 2014, 06:16:29 am
content: I don't have one of these, but did look at buying one.- I had a look at the Korad thread that's been running and the build quality of the new ones look very good.Just a few extra notes, there is not much info about the Hantek so here is what I have.Hantek PPS2116A Power Supply- The Hantek has had 2 known problems in the past. One is the output turning on during powerup, 20+ volts, not good. The other was a voltage ramp up (a few volts over) that occurred only when adjusting the voltage while the output was enabled (also not good). The unit I have has neither of these issues and I haven't found any complaints about the unit in over 7 months.- The Korad seems to have an overshoot issue, the Hantek does not seem to have had the same issue.- One minor issue I have noticed is that if you have no current level set the voltage will ramp up slowly (takes about 1.5 seconds when output enabled). It does not occur if you set 0.001 (the minimum) current. In reality the supply would never be used with the current limit set to zero, unless like me you where not paying attention.- I've had the thing for about 3 weeks, it had one good run appx 3 days (72hrs) 13.8 volts @ 320ma ish continuous, no issues.If anyone else has had one of these for a while I'd like to hear about any issues.

author: rdl
author_rank: Super Contributor
timestamp: February 09, 2014, 05:03:04 pm
content: For some strange reason, people only seen to remember or recount the EEVBlog episode where the Korad failed. They almost always ignore the two followup videos. Go to YouTube and type this into the search box:Korad FollowupWatch both these videos start to finish, EEVBlog #404 Korad PSU Followup (EEVBlog) and Korad Power Supply Followup (Altzone), then decide who gets your money.Quote from: Dave Jones (EEVBlog #404)

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 09, 2014, 05:46:46 pm
content: I haven't looked closely but I don't recall seeing Dave use the korad since. Don't remember seeing it on the bench even. It's probably for sale on his store.These are the only videos I've seen are there others?EEVblog #314 - Korad KA3005P PSU TeardownEEVblog #315 - Korad KA3005P Review_FAILEEVblog #404 - Korad PSU FollowupA. We found serious issues on-camera.B. You completely redesigned the product only because you were publically embarassed.C. Now we should trust you and spend our money on your "equipment".I didn't come to the conclusion in CI came to the conclusion that I'll not buy any of your "equipment" and I will look for known brands and buy used.

author: rdl
author_rank: Super Contributor
timestamp: February 09, 2014, 06:17:59 pm
content: Some companies will just ignore problems, even if exposed. Some will be responsive and actually try and fix problems.Which will you buy from?I wouldn't expect Dave to actually use a Korad. Unless I have totally missed the point, the debate here is a power supply in the $100 range. Dave can pick and choose between whatever luxury items he has available and deal with their problems as he sees fit.I don't need a power supply, I have several already that work fine, but if I needed a new one today I think I'd lean toward the KoradBuy whatever you want, then do this to it and come back and share your results:

author: Electro Fan
author_rank: Super Contributor
timestamp: February 09, 2014, 07:40:16 pm
content: Quote from: pickle9000 on February 09, 2014, 06:16:29 amI have seen the same result if the current is set under about .003 amps but with anything from .004 amps and up the PS responds rapidly. Your experience and mine are consistent with FAQ 3 in the Korad manual:Q3: Output voltage rises slowly when output button is on.A3: Current setup is too small.As for turn-on overshoot here is a link to some results:https://www.eevblog.com/forum/testgear/how-to-fry-a-korad-in-less-than-a-second/msg340781/#msg340781In my opinion the Korad KA3005P is capable of performing with reasonable "enthusiast level" reliability, performance, and precision; additionally it is compact and easy to use. It is of course possible to have a defective unit. If you buy from a reputable seller (I really like SRA Soldering) you should be able to get support if you need it. My impression is that while earlier units had some issues Korad has been attentive and made improvements.If you pay more you can get some more features and performance but even then flawless design is not guaranteed (just read the Rigol DP832 threads). I think what we are seeing is that older, precise, and reliable designs (from Agilent and others) have stood the test of time and if you are willing to pay somewhat more such power supplies can be a great choice.On the other hand, if you have a somewhat lower budget and you would also like more modern features you now have some choices including Rigol, Korad, and various other manufacturers. In return for pushing price down and trying early releases of products you take some risk. Having said this, I think that once you get by the early release period (where users help shake out design flaws that probably should have been found and addressed by manufacturers' QC), it is possible for several hundred dollars (in the case of the Rigol) to get a very flexible, very feature rich power supply that is reliable. (I think one by one Rigol will get most of their issues sorted out). For even less (under $150) you can purchase a single channel programmable power supply from Korad and get reasonable performance and reliability.If you are a pro and you have many hours and dollars invested in your designs it probably makes sense to spend more and take less risks. If you are an enthusiast on a budget a Korad seems like a good value.In all cases, we are dealing with 120 Volts (or more) on the input side so I think we need to always stay vigilant as users to make sure we aren't saving money at the expense of safety - but once above a safety-first threshold then I think it's reasonable to look for increasingly more features and performance per dollar.

author: dssence
author_rank: Regular Contributor
timestamp: February 09, 2014, 08:18:37 pm
content: Hi thanks to all of you guys for all the help, I thought the korad were crappy cause the vids I've seen o youtube. And I was thinking on ordering directly from SRA solder. So I think it's areputable seller. On the other hand I came up to this one .. but I don't see it's got a short circuit protection or I could set up the limiting current protection as well.https://www.circuitspecialists.com/i-182253.htmlCan you set up the protection on current limiting on the korad? So which is the good Korad supply Part number which its fine to get ? I'm looking for 5amps 30volts

author: Pasky
author_rank: Regular Contributor
timestamp: February 09, 2014, 10:09:32 pm
content: What's the difference between the Korad 3005D and 3005P?

author: Electro Fan
author_rank: Super Contributor
timestamp: February 09, 2014, 10:11:51 pm
content: Quote from: dssence on February 09, 2014, 08:18:37 pmI haven't purchased anything from Circuit Specialists but I think they are pretty reputable.The product you found looks good - might be worth a try.I think it is roughly the equivalent of the Korad KA3005D:http://sra-solder.com/product.php/6946/1/korad_ka3005d_dc_precision_variable_dc_power_supply/b34aaa17543a36edd043ad9317dd32daThese two don't seem to be programmable (via a PC) but the Korad does have memories. On the other hand the CS product goes up to 10 amps (vs. 5 on the Korad), and it's about $15 less.You might compare the specs.For about $15 more (vs the 3005D) Korad offers the KA3005P:http://sra-solder.com/product.php/7007/0/korad_ka3005p_dc_precision_variable_dc_power_supply/f96e55eca79a48e95375445f2ce80cbbMy guess is that you couldn't go too far wrong with any of the three. (None of the manuals are super duper but you might take a quick glance to get a feel for the specs and how they operate.)Here is another CS unit I noticed:https://www.circuitspecialists.com/dc-bench-power-supply-csi3005x5.html- Some folks here like to say everyone just pushes what they own as a way to justify their own purchase. In my case I'm happy with the Korad 3005P but I've already made the decision and I don't need anyone to validate my choice. I'm more interested in discovering what else is out there - so I'd be happy to hear from someone who buys the CSI3010SW, or any other model. Let us know what you go for and how it works. EF

author: Electro Fan
author_rank: Super Contributor
timestamp: February 09, 2014, 10:13:26 pm
content: Quote from: Pasky on February 09, 2014, 10:09:32 pmThe P has a USB interface so you can monitor it and program it from a computer. The D doesn't have the USB computer interface, thereby saving about $15.

author: pickle9000
author_rank: Super Contributor
timestamp: February 09, 2014, 11:54:35 pm
content: The unit from circuit specialists is a switching supply. Not typically recommended for bench work unless you need the massive current. I don't know what you use is but a linear supply is probably what you want.Having the usb functionality can be really helpful by freeing up a meter (for current logging) or emulating a battery.@Electrofan- I noticed that the Korad micro is still unknown, the Hantek is using an ATMEGA8A.- Do you know if there is any info on overshoots at or under 5 volts (3.3 in particular would be nice)?- Does the Korad have an SDK or command list for the USB? (Hantek does have an SDK)

author: Electro Fan
author_rank: Super Contributor
timestamp: February 10, 2014, 12:01:05 am
content: Quote from: pickle9000 on February 09, 2014, 11:54:35 pmGood catch on the CS unit being a switching PS; I'm definitely in favor of linear PSs for bench work - it was one of the first requirements I had when I got started on all this hands-on EE stuff from near scratch about a year ago.I'll see if I can address your 3 items later - currently getting ready for the coming work week...

author: Pasky
author_rank: Regular Contributor
timestamp: February 10, 2014, 12:03:54 am
content: Damn I'm really on the fence here with the Korad P model...is there more bang for your buck on something else for under $200? Otherwise it looks like I'll be grabbing an updated Korad. But that's my other worry, that I'll buy old stock with the supposed "bad transistors" Korad mentioned.

author: Electro Fan
author_rank: Super Contributor
timestamp: February 10, 2014, 12:05:04 am
content: Quote from: Electro Fan on February 10, 2014, 12:01:05 am

author: Electro Fan
author_rank: Super Contributor
timestamp: February 10, 2014, 12:07:49 am
content: Quote from: Pasky on February 10, 2014, 12:03:54 amNo worries - call SRA Soldering, make it clear you want the latest version (or at least no wrong version), they will say sure, ship you a unit, if you have any issues they will take care of you. The owner, the office workers, the tech support mgr are all the real deal when it comes to customer sat. Ask them what their return policy is in case you are not happy - not sure what they will say about that but I'll bet it will be somewhere between reasonable and pleasant.

author: robrenz
author_rank: Super Contributor
timestamp: February 10, 2014, 02:07:13 am
content: These are tough to beatPower designs 6050, very versatile and high quality.

author: dssence
author_rank: Regular Contributor
timestamp: February 10, 2014, 02:52:25 am
content: Damn now I'm trying to see if I ask for the korad to SRAsolder. I heard there are some issues about bad transistors or new revisions. So what would be the best choice. should I go with the korad ?-Any difference between KORAD KA3005P or D ? about issues or malfunction badly manufactured unit ?- Is hantek better than KORAD?http://www.ebay.ca/itm/Hantek-Programmable-High-Precision-Lab-Bench-DC-Power-Supply-PPS2116A-/221265590812?pt=LH_DefaultDomain_0&hash=item338474fa1c, any place in the US where I can buy this hantek ?- What's the difference with the previous korads with this one , no protection short circuit or overcurrent if the device exceeds amperage setted.http://sra-solder.com/product.php/7163/128/korad_kd3005d_dc_precision_variable_dc_power_supplyI'm looking for 30V 5amps- Built in cooling fan which adjusts accordingly with load. ( NO JUMBO NOISE)-Multiloop high precision voltage regulation-Progressive current regulation-Overload protection circuit-Current Protection limit if I can set say a specified amperage and if the device draws more it autoprotects-Low ripple voltage ( What should I check here below 1mv ? what's best? )Source effect: ?Load effect: ?Ripple coefficient: What should I take into consideration ?

author: jwm
author_rank: Regular Contributor
timestamp: February 10, 2014, 03:11:02 am
content: Quote from: pickle9000 on February 08, 2014, 07:25:40 pmI guess this is what I am asking about, with my current supply since the meters show just the actual current/voltage, I don't have any feedback about what I am actually setting the max of each are when moving the knobs. for instance, I may have something drawing one amp, and I want to give it a 1.5 amp limit, but when I turn up the current knob, it doesn't change anything on the display because it still shows the one amp the DUT is currently drawing, so I have no idea whether I set it to 1.5 amps or 4 amps until the device actually shorts and accidentally draws the 4 amps. What I'd like is feedback about what I'm actually setting the maximum value too for each in addition to the actual immediate values if that makes sense.Is "Programmable" the magic word I should be looking for in specs? For some reason I thought that meant it had some sort of way to connecting to a computer, but it looks like it may mean what I want.

author: pickle9000
author_rank: Super Contributor
timestamp: February 10, 2014, 04:00:36 am
content: @robrenz- You really like that supply. I actually had one a quite a few years ago, good/excellent yes but my eyes just can't handle needles any more.@dssence- It looks as if the ebay guy either is or has a contract for Hantek stuff. Here is the US link same place though. Comes from Canada. FYI these guys prices are way lower than aliexpress even if you take the shipping into accounthttp://www.ebay.com/itm/Hantek-Programmable-High-Precision-Lab-Bench-DC-Power-Supply-PPS2116A-/221265590812?pt=LH_DefaultDomain_0&hash=item338474fa1c. According to the ebay listing no import charges or tax for US customers. So that is good. It also says introductory price and it does seem low so that is also a bonus.- For the Korad numbers. The two you mentioned are the same but one has USB. Get the USB version if you go the Korad route. I can't really say more than that I don't own one.- Specs, both the Korad and Hantek spec out pretty much the same the only real difference is the overshoot. Ideally you will have no overshoot (that is a higher than normal voltage when you first turn on the output). The Hantek does not appear to have any overshoot issues at all.@jwm- Programmable basically means a micro is setting up the supply. Unfortunately that does not mean you will get the set features you want. You will need to read the manual and hopefully you will have it there in black and white. Other than that ask questions.- The Hantek I have will allow you to adjust current and voltage while the output is on. Basically you push Volts then make the adjustment for volts. Current operates the same way but the display shows the maximum set current while the adjustment is made and then reverts back to showing current draw after 3 seconds. That is what I would like to see on all supplies but that depends on the software designer.- One thing I really like on any supply is a knob, I hate pushing buttons to set a voltage.- In the old days (I'd say "when I was a boy" but I was actually older than that) it would not be uncommon to see a current set knob with felt marks indicating the rough current.

author: dssence
author_rank: Regular Contributor
timestamp: February 10, 2014, 04:08:05 am
content: Quote from: pickle9000 on February 10, 2014, 04:00:36 amHi thanks for your help, can you explain to me about the overshoot you said. I also need to know is there a current amperage threshold you can set. So say I set amps at 4.5 and the device draws way more.. what will happen. I hear there's an option to set an amps threshold or something. Is that available on korad or hantek ? Is there any difference with the toroidal transformer with the norma lone?

author: Electro Fan
author_rank: Super Contributor
timestamp: February 10, 2014, 04:15:42 am
content: If want a Korad and you can wait until March this could be the new low cost leader at $79.99 (including free shipping - probably in the U.S.):http://www.ebay.com/itm/KORAD-PRECISION-VARIABLE-ADJ-30V-5A-DC-POWER-SUPPLY-DIGITAL-REGULATED-LAB-GRADE-/131013279686?pt=LH_DefaultDomain_0&hash=item1e80ffffc6"If your product is damaged in shipping or is found to be defective in any way during the 1st 30 days after receiving the item, we will pay to have the defective/damaged product returned to us and issue you a 100% refund or we will repair or replace the unit at no charge.If the buyer is returning the product due to "Buyer's Remorse", then the buyer is responsible for the return shipping. The product must be returned "NEW & UNUSED" as it was received in the original box with all parts/paperwork.You will need to contact us for a Return Authorization Number before you return it for any of the reasons above."

author: dssence
author_rank: Regular Contributor
timestamp: February 10, 2014, 04:19:21 am
content: Quote from: Electro Fan on February 10, 2014, 04:15:42 amHi is this better than the other 2 korads? or there are functions missing.

author: pickle9000
author_rank: Super Contributor
timestamp: February 10, 2014, 04:50:36 am
content: @dssence- Current limiting is the default setting for this type of supply. Just like it sounds it prevents whatever you hook up from taking more current than you set. If you set it for 1 amp it will only deliver 1 amp no matter what (even if the circuit wants more). The other setting is Over Current Protection, if you set the over current protection for 1 amp the controller will turn off the output if the draw is over 1 amp. Current limiting has many uses, Over Current Protection is protective, preventing damage.- Overshoot is related to voltage. Lets say you set your voltage to 12 volts, you turn on the output and for a split second the voltage reaches 12.5 volts (a 0.5 volt overshoot) then settles down to 12 volts. Depending on the situation you can damage the device you are powering. Overshoot is not unusual in a supply but is not desirable particularly in a bench supply.- That new Korad does not have presets (memory) and does not appear to have USB. Presets are a very handy feature, same for the USB. Other than that it looks the same.

author: Electro Fan
author_rank: Super Contributor
timestamp: February 10, 2014, 06:04:06 am
content: Quote from: dssence on February 10, 2014, 04:19:21 amThis is not better, just less expensive. If you can afford the KA3005P, that would be the way to go; next is the KA3005D, then the $79 model. Kind of depends on your needs and budget.

author: dssence
author_rank: Regular Contributor
timestamp: February 10, 2014, 02:45:35 pm
content: HI so I came across this guy from poland , and I didn't like what he said about the korad he got. Makes me really think it twice.Any advice? on some other brand .Quote

author: rdl
author_rank: Super Contributor
timestamp: February 10, 2014, 05:50:11 pm
content: QuoteIf you look at his photos you can see the power board and it looks like the early version, before they fixed the problems with the output transistors (in EEVBlog #404 you can see the old and new boards side by side).

author: pickle9000
author_rank: Super Contributor
timestamp: February 10, 2014, 07:09:55 pm
content: @dssenceMy advice is that if you don't have confidence in the Korad don't buy it. "Confidence" is an important word in electronics, if you can't trust your equipment everything will take longer.Look at the Rigol 832 that Dave just purchased. He has confidence in Rigol, the supply had some features he wanted and a good price. What happened? It had a design fault (a couple at least). Rigol fixed the issues and repaired the faults. Rigol did good, they may have not fixed the problems to everyone's liking but they did fix them. Korad and the sellers of Korad products could learn a lesson, stating that it is a revision 2 unit or whatever and stating that upgrades have been done. The problem with that of course if that you could have 20,000 customers knocking on you door saying fix the old one.As for me I went and ordered another Hantek unit. The price was just too good to resist. My confidence in the unit is good enough to do that. I will end up changing the electrolytics in it but don't take that as meaning it's crap. I have done this for many years. Electrolytic capacitors are the most common thing to fail in any equipment and I like to have nice ones in place. I still don't know the OEM for this supply but it certainly has been built down to a price. If you do go for the Hantek, I purchased from techrecommends in Canada. I'm in Canada so for me that was part of the decision. I don't know who the guy is but I think it is either a Hantek dealer or Hantek itself. Most of the other stuff being sold seems a little overpriced for an ebay seller.

author: dssence
author_rank: Regular Contributor
timestamp: February 10, 2014, 09:40:03 pm
content: Quote from: pickle9000 on February 10, 2014, 07:09:55 pmHi thanks so much I've finall decided to guy with mastech either of these which one would be best? Maybe the 10 amps is better built. Now will these units if I say. Set the amps to 4.5 amps and voltage to 5volts and my device starts drawing more than 4.5amps. Will the supply overprotect I do hope it does have shortcircuit protection both can you help me outhttp://www.ebay.com/itm/MASTECH-HY3010E-30V-10A-Lab-Grade-Regulated-Variable-Linear-DC-Power-Supply-/221291395770?pt=LH_DefaultDomain_0&hash=item3385febabahttp://www.ebay.com/itm/Mastech-HY3005D-Lab-Tattoo-Linear-Variable-DC-Regulated-Power-Supply-30V-5A-110V-/140985160837?pt=LH_DefaultDomain_0&hash=item20d35ed485

author: pickle9000
author_rank: Super Contributor
timestamp: February 11, 2014, 02:27:41 am
content: I think you have enough info to figure out the rest, read the manuals (use pfd in the search). Search the forum here is the one from your last posthttps://www.eevblog.com/forum/testgear/mastech-hy3010e-3-power-supply-noise/.Any time you see a supply with more than 3 amps make sure you check the manual to ensure it is not a switching type. The hy3010e appears to be a switching one and is probably labelled incorrectly on ebay. As for the other one any time you see "power supply" and "tattoo" in the same line going elsewhere is probably best. That has nothing to do with the supply just a bit of common sense.I can't give any advise on Mastech stuff I don't own any. I'm sure you can find some reviews.Remember supplies are normally purchased according to the job they need to do. When you can't find one to do the job you build it. In my experience having 3-5 bench supplies is perfectly normal, more in many cases. That does not include the box in the closet with specialized fixed ones.

author: dssence
author_rank: Regular Contributor
timestamp: February 11, 2014, 02:41:22 am
content: Quote from: pickle9000 on February 11, 2014, 02:27:41 amDamn this is almost impossible, near all the linear supplies have one or another problem . I thought this mastech was a good one and now it results it does have more noise than the acceptable levels on spec.What about this one insteadhttp://www.ebay.com/itm/Mastech-HY3005D-Lab-Tattoo-Linear-Variable-DC-Regulated-Power-Supply-30V-5A-110V-/140985160837?pt=LH_DefaultDomain_0&hash=item20d35ed485I'm honestly tired there's like nothing without it's cons

author: Pasky
author_rank: Regular Contributor
timestamp: February 11, 2014, 04:30:10 am
content: I think in a couple weeks I'm going to grab the Korad, after watching Dave's reviews, it seems like a nice unit for the price other than the transistor problems, which seems to have been resolved.

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 11, 2014, 05:43:49 am
content: I don't know a lot about BK products (I own a BK DMM) I think the company's been around for a long time. I do recall seeing a BK power supply on Dave's bench.36V and 3A and $107 with a trade-in of anything (I don't think they care what you trade-in I've entered Micronta 22)https://www.bkprecision.com/products/power-supplies/1550-switching-dc-bench-power-supply-with-usb-charger-output-1-36v-0-3a.htmlTriple output,One variable 0 to 30 VDC, 0 to 5 A variable section, One 12 VDC fixed section, One 5 VDC fixed section$157.68https://www.bkprecision.com/products/power-supplies/1671A-triple-output-30v-5a-digital-display-dc-power-supply.htmlThis one's interestingDigitally controlled, mixed mode linear/switching DC power supply for $208https://www.bkprecision.com/products/power-supplies/9110-100w-multi-range-60v-5a-dc-power-supply.htmlAll those prices I found by going to this page:https://bkprecision.com/promotions/exchange-program.htmlThe exchange doesn't seem to matter, you can enter in a $3 pocket DMM and they give the same discount. I have not tried it yet but may be getting one of the above. Possibly the 9110 unless I find a horror story about it.

author: nanofrog
author_rank: Super Contributor
timestamp: February 11, 2014, 06:07:32 am
content: Go with a used unit. You can get a lot more PSU for the money (linear, better specs, built like a tank, dual or even triple output) for similar money as you've been looking to spend. Worst case, you'll need to be a little patient for the right unit at the right cost to be posted.Example.

author: London Lad
author_rank: Regular Contributor
timestamp: February 11, 2014, 09:08:37 am
content: ^^^ agreed. most of these cheap new units are of poor build quality.As I said before a good used farnell supply is a far better bet. Farnell the manufacturer not Farnell the retailer that is.

author: dssence
author_rank: Regular Contributor
timestamp: February 11, 2014, 01:33:21 pm
content: Guys do you know if this hantek supply is switched supply or linear regulated ?HANTEK PPS2116Ahttp://www.hantek.com/en/ProductDetail_33.html

author: Fsck
author_rank: Super Contributor
timestamp: February 11, 2014, 02:29:51 pm
content: Quote from: dssence on February 11, 2014, 01:33:21 pmlooks linear to me.

author: Electro Fan
author_rank: Super Contributor
timestamp: February 11, 2014, 08:14:56 pm
content: looks like a whole family of Power Supplies:http://www.hantek.com/en/ProductList_1_10.html

author: HiTech
author_rank: Regular Contributor
timestamp: February 11, 2014, 09:00:15 pm
content: I didn't read every reply due to the 5 pages of tedious reading but my serious advice is to forget the Asian crap out there and buy used HP, Power Design, Sorensen, or Trigon. These are high quality linear supplies built like brick $hit houses, capable of withstanding daily stresses. I just sold a working HP 0-40v 5amp supply on another electronics forum for under $50. EBay has many of them up for sale... my preferred favorites being either HP or Power Design brands. They often sell for well under $100 and more typically around $50. Adjustable voltage, adj. current, short-proof, meters to monitor both voltage and current and much more. Avoid the weaklings like Mastech, Instek, B&K, Tenma, etc. Even the VIZ line is better than the weakling brands I just mentioned.

author: robrenz
author_rank: Super Contributor
timestamp: February 11, 2014, 09:06:17 pm
content: Quote from: HiTech on February 11, 2014, 09:00:15 pm+1 excellent advice

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 11, 2014, 09:23:57 pm
content: Hadn't heard of Trigon before, there's also a Thandar brand I see on ebay but don't know about it. I like the look of the power design with the aluminum knobs. Advantest was reviewed recently too, but high end. All the asian stuff is getting scarier all the time. The rigol dp832 and then there's the Youyue 858D+ thread here and then I've heard mention of other manufacturers cloning the asian stuff. We all know what happens when you copy an already bad copy.

author: pomonabill221
author_rank: Frequent Contributor
timestamp: February 11, 2014, 09:47:08 pm
content: There is also Lambda power supplies.

author: jadew
author_rank: Frequent Contributor
timestamp: February 11, 2014, 09:53:00 pm
content: Personally, I like the Korad. Seems simple enough to work / fix / mod and is programmable.Only issue I've been having is that I can't find it in the EU, not with out paying twice what it's worth.Edit: I like the front panel as well, although I would have preferred it if it had two pushable knobs for voltage and current, instead of those 3 buttons + knob.

author: nanofrog
author_rank: Super Contributor
timestamp: February 11, 2014, 09:55:49 pm
content: Quote from: GiskardReventlov on February 11, 2014, 09:23:57 pmNever heard of Trigon, butThurlby Thandar Instruments(Aim-TTi) I have. They've been around for a good while from what I understand, and have made some excellent gear.

author: jadew
author_rank: Frequent Contributor
timestamp: February 11, 2014, 10:11:26 pm
content: I've heard of TTi as well, haven't heard of Sorensen tho.Now the question is which is which? Because they're both expensive:

author: edavid
author_rank: Super Contributor
timestamp: February 11, 2014, 10:15:33 pm
content: Quote from: nanofrog on February 11, 2014, 09:55:49 pmTrygon [note spelling] was a company that was bought by Systron-Donner, so you see their stuff labeled with various combinations of those. I don't think their power supplies were anything special though.Thurlby may have made some good equipment, but Thandar, not really. The TTi power supplies do seem nice, but they are overpriced in the US.

author: nanofrog
author_rank: Super Contributor
timestamp: February 12, 2014, 02:23:54 am
content: Quote from: edavid on February 11, 2014, 10:15:33 pmThanks.All the mergers & acquisitions and/or rebranding products from an ODM is enough to make my head spin most of the time.

author: staxquad
author_rank: Frequent Contributor
timestamp: February 12, 2014, 03:06:57 am
content: Quote from: jadew on February 11, 2014, 10:11:26 pmAmetek, Elgar, Sorensen, XANTREX, all same company, some models have 3 different names on ithave seen many under $100 on EbayDave reviewed a high voltage Xantrex, exuded quality throughout

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: February 12, 2014, 04:23:59 am
content: Some good new search terms for ebay! I've seen systron-donner. I've also seen Kepco and Kikusui.

author: Electro Fan
author_rank: Super Contributor
timestamp: February 12, 2014, 05:22:29 am
content: TTi is the real deal. Don't know much about the others. For anything over $100 I'd be looking for a power supply that can turn the output(s) on and off without using the main AC switch.

author: dssence
author_rank: Regular Contributor
timestamp: February 12, 2014, 05:16:17 pm
content: SO guys can anyone help me out if the HANTEK PPS2116A is indeed a linear power supply and not switching . I was going to go with that one. I couldn't find anything on ebay on 30v 5amps under 120 bucks on these brandsHP, Power Design, Sorensen, or Trigon.

author: robrenz
author_rank: Super Contributor
timestamp: February 12, 2014, 05:56:26 pm
content: You obviously ignored my previous post in this thread.Here it is again relistedNo one bid last time at $99.00 starting bid. Contact the seller and offer him $80.00 as a buy it now price. If he agrees he can change the listing tell you when he is going to do it so you are ready to pounce on his buy it now price.

author: Rigby
author_rank: Super Contributor
timestamp: February 12, 2014, 05:59:52 pm
content: If you want to wait until a make & model comes out that has zero problems in the field, you are going to wait forever.I'm not sure why you're hell-bent on getting a new power supply over a used one.Depending on your current needs --both amperage & timeframe-- there are plenty of very inexpensive supplies on eBay that work just fine. I have bought two supplies on eBay, both of which said "Not working, for parts" and after reading the description I decided that I would pay $15 and try my luck. In both cases I won the auctions and got supplies that work JUST FINE but have either a small cosmetic issue or simply weren't tested by the seller. One is an HP 6286A, 0-20V, 0-10A, the other is a Power Designs 3650-S, 0-36V, 0-5A. I designed a 3D printed a meter clip for the HP at home, printed it at work, and I adjust the voltage & current on the Power Designs supply with a multimeter connected. Solved, for $100 total in purchase price and shipping, and I now have two excellent supplies.I also have a Rigol DP832 that works great. Yeah, you need to wire output 2 & 3 ground terminals together externally. Yeah, there's a small output spike on each channel, but they are so short and have so little "oomph" behind them that I don't worry about it a lot. I'm aware of it, though, and when I am doing work where a short small spike would cause damage, I just won't use that supply or I'll put a tiny cap in series or something. As long as you KNOW the problem(s) that your supply has, it doesn't matter what the problems are.Knowing the problems and knowing when/how to deal with them is far more important and far easier than finding a supply with no problems.

author: nanofrog
author_rank: Super Contributor
timestamp: February 12, 2014, 06:26:48 pm
content: Quote from: Rigby on February 12, 2014, 05:59:52 pmWondering the same exact thing, as there are more than enough posts mentioning used over new that the OP should have noticed by now.A case ofMust have NEWfever perhaps?

author: dssence
author_rank: Regular Contributor
timestamp: February 12, 2014, 08:04:15 pm
content: hey thanks to all of you for helping out. Honestly I wanted to have a new supply rather than risking myself with a used one. I know it might sound stupid, but I feel the hantek seems solid. Problem is I don't know if it's linear or a switched mode. I already sent a couple of emails to hantek waiting for them to reply. Thanks again. Is there any difference on some of the supplies using a toroidal kind of transformer instead of a standard one ? how does it affect performance.

author: Rigby
author_rank: Super Contributor
timestamp: February 12, 2014, 08:28:04 pm
content: Quote from: dssence on February 12, 2014, 08:04:15 pmYou are worrying about the wrong things.Any respectable bench supply is going to be linear, probably. If it's not, they're probably not a great supply manufacturer. In truth it probably doesn't matter much if you're not going to use it for anything super delicate or of audiophool quality. TVs and radios and computers all use switched power supplies in production. Honestly, if it's that important, you could probably use a switched supply if you didn't mind regulating linearly between the power supply and the circuit you're building.Toroidal transformers are more efficient, but they don't affect the output voltage when compared to traditional E I cores. The output is rectified and linearly regulated so it won't matter much, if at all.Hantek are absolute rubbish compared to an older HP supply. The old designs are rock solid and rarely experience failure. And when they do, you walk to your printer and look at the schematic you just printed and you find the part that went out. You go to the computer, order a new one, and when it comes in you install it. Fixed. My HP 6286A has a massive, 50 year old 33000uf electrolytic cap in it that still cuts the mustard quite happily. The variac in my Power Designs 3650-S still works just as well as it did when it was new. The primary voltage adjustment is a damn variac of all things, coupled physically with a potentiometer. Actually, maybe it's just a giant wire-wound high-wattage potentiometer, I don't know. Schematic has been ordered and will be here this week.Don't let 7-segment readouts get the best of you. The new supplies just are not as good for a beginner. Plain and simple.

author: nanofrog
author_rank: Super Contributor
timestamp: February 12, 2014, 08:49:58 pm
content: Quote from: dssence on February 12, 2014, 08:04:15 pmI'm withRigby. Definitely looking at this from the wrong perspective.Simply put, the currently produced inexpensive Chinese offerings just aren't built anywhere near as solidly or reliably as the older, top quality used supplies that are available on places like eBay. Period.Look at it this way... Those old beasts are still happily chugging along doing the job they were made for decades later. Do you seriously think that cheap Chinese station will make it anywhere near that long, given all the issues that have turned up already, and is occuring with multiple manufacturers?Something to think about.

author: sync
author_rank: Frequent Contributor
timestamp: February 12, 2014, 09:03:33 pm
content: Quote from: dssence on February 12, 2014, 08:04:15 pmThat's a valid reason. But don't expect quality at these low prices.Is Hantek the original manufacture or is it just rebanged?Read the manual to get a first impression.Search the internet for reviews and problems with this model.Then you find this:https://www.eevblog.com/forum/testgear/hantek-power-supply-pps2116a-review/Knowing that is also a Protek P6035, Vantek DPS 3305P or Quakko HY3005DP search again. You will findhttps://www.eevblog.com/forum/reviews/0-32v-0-5a-with-usb-control-protek-p6035-quakko-hy3005dp/. In this thread is a videoSo this power supply is a killer. In a bad sense. It kills your projects.Look for another power supply and do some research like written above.

author: dssence
author_rank: Regular Contributor
timestamp: February 12, 2014, 09:12:50 pm
content: Quote from: sync on February 12, 2014, 09:03:33 pmHi thanks so much for worrying about my decision. SO what's this guy telling basically with the scope. That initially this supply instead of outputting 5 volts DC it's outputting 25 v instead of 5 volts?. How could this be possible ?. If these manufacturers are building supplies with this time specific milliseconds of outputting a different voltage than it's being setted up .Could this also apply to the hantek I'm going to buy. I honestly don't get it.

author: Rigby
author_rank: Super Contributor
timestamp: February 12, 2014, 09:32:52 pm
content: Quote from: dssence on February 12, 2014, 09:12:50 pmYes. Don't buy it. Get something used, something that's been through a lot of use and came out still functioning.HP. Power Designs. Agilent. Hell, even Elenco or Heathkit.Or, maybe the better course for you would be to use an ATX power supply and a linear regulator, if your current (amperage) requirements aren't high. That is certainly the least expensive option and is the most flexible, it just requires a wee bit of know-how on how to do it. It isn't hard.

author: robrenz
author_rank: Super Contributor
timestamp: February 12, 2014, 09:39:42 pm
content: 6 pages of advice and your not listening to us..... I give up

author: nanofrog
author_rank: Super Contributor
timestamp: February 12, 2014, 09:55:13 pm
content: Quote from: robrenz on February 12, 2014, 09:39:42 pm+1BTW, how do I unsubscribe from this thread?

author: mrflibble
author_rank: Super Contributor
timestamp: February 12, 2014, 10:15:51 pm
content: yay! More old HP PSU's on the market for me.Not that there's anything nearly as affordable for us Europeans ... Typically those nice HP PSU's are from the US and shipping kills it.

author: sync
author_rank: Frequent Contributor
timestamp: February 12, 2014, 11:50:48 pm
content: Quote from: dssence on February 12, 2014, 09:12:50 pmTwo possibilities. The designers don't know what they are doing or they don't care.

author: Rigby
author_rank: Super Contributor
timestamp: February 13, 2014, 02:01:20 am
content: Quote from: sync on February 12, 2014, 11:50:48 pmOr they are being instructed not to care, in order to cut costs.

author: tikicarver
author_rank: Newbie
timestamp: February 15, 2014, 12:23:25 am
content: I think it depends on which one you buy. I bought the Hantek PPS2116A (32v/5amp) on Ebay.It does not have the power spike like other ones people are talking about.I got it for $99 on ebay from a dealer in Canada ( he already sold out, said will have more in April)I checked it with a scope. First of all, it has an output On/OFF button and when you turn on the main power of the unit the output is always off. When turning on the output with the button, there is no spike, it goes to the selected voltage with no overshoot and when turning output off, there is also no spike, the voltage drops and looks like a cap discharging.It also has computer control. Haven't played with that yet.Looked inside and it as a large torriodal transformerI am very happy with the PS.I think you need to be careful when saying they are re-branded and all the same.

author: dssence
author_rank: Regular Contributor
timestamp: February 15, 2014, 12:54:02 am
content: Yep damn I'm trying to get the hantek and this supplier from canada doesn't have anymore in stock. Any ideas in the US who might have hantek ?

author: Electro Fan
author_rank: Super Contributor
timestamp: February 15, 2014, 01:04:57 am
content: Question: which is worse (harder on a test circuit):a) a power supply turn on spike that goes +/-20 volts for 100usorb) a power supply turn on spike that goes +/- 2 volts for 1msor is it case dependent?Thanks

author: dssence
author_rank: Regular Contributor
timestamp: February 15, 2014, 01:28:04 am
content: I think what would states varies accordingly to the type of circuit you're testing. It it's a TTL cmos circuit it won't tolerate a huge difference you could fry the IC . Anyways to me it's not acceptable that a lab supply as soon as you shift the knob for voltage doesn't accomodate to the voltage you specify and overshoot. Simple as that not acceptable. !

author: dssence
author_rank: Regular Contributor
timestamp: February 15, 2014, 02:48:53 am
content: What about this supply it's attenhttp://www.ebay.com/itm/Atten-TPR3005T-single-constant-voltage-constant-current-DC-power-supply-/110804972338I couldn't find any reviews or if it's rebranded. Any ideas?

author: rdl
author_rank: Super Contributor
timestamp: February 15, 2014, 03:43:29 am
content: One problem buying cheap Chinese stuff is the lack of consistency. One batch may be fine, then for the next run the Chinese bean counters substitute half the parts with cheaper ones that don't work or fail early or have some other problem. It's a crap shoot. You might as well just flip a coin.Buying a Korad from that SRA company on eBay seems pretty safe. They have a very good guarantee in case you have issues once you get it. The little 18 volt 3 amp job from Circuit Specialists also looks good, it's already so cheap I doubt anyone could change something to make it cheaper.

author: dlt123me
author_rank: Newbie
timestamp: February 22, 2014, 03:42:38 am
content: Quote from: robrenz on February 12, 2014, 09:39:42 pmAfter reading this thread and lurking around for awhile... I had to join the forum to give my thanks for everyone's advice in this thread...Just so you know, someone is listening. I was going to get one of the Asian units that most are looking at, but after reading all the posts here suggesting used HP, Agilant and other older power supplies, I've decided to buy a used unit instead of one of the newer China made power supplies...It makes sense, if they have been around all this time and still work, that says a lot.. I just won't have all the fancy push buttons, displays and programmed settings. I want stability.So, thanks to all of you who have suggested getting a used PS. I get it now...Dennis

author: dlt123me
author_rank: Newbie
timestamp: February 22, 2014, 04:42:40 am
content: I don't have a power supply yet, but have been looking at used models of HP and other used PS's on eBay.Are these good specs for a triple output unit?Output Ratings (Maximum current is derated 3.3% per °C from 40°C to 55°C)Output 1: 0 to 6 V, 0 to 2.5 AOutput 2: 0 to +20 V, 0 to 0.5 AOutput 3: 0 to -20 V, 0 to 0.5 APower (max): 35 WRipple & Noise from 20 Hz to 20---------------------Are the amps too low? It seems that .5A is way too low... What would this power supply be used for?Also, what good is having the ability to use 0 to -20Volts? I'm new to electronics, and I have never heard of a negative volt.Thanks,Dennis

author: Pasky
author_rank: Regular Contributor
timestamp: February 22, 2014, 05:01:58 am
content: I know some old arcade boards would use a -5V or -12V. Not really sure what the actual point of it was.

author: nowlan
author_rank: Frequent Contributor
timestamp: February 22, 2014, 05:05:54 am
content: op ams used to need negative rails.edit: rs232 wants negative too.

author: Joule Thief
author_rank: Regular Contributor
timestamp: February 22, 2014, 05:15:39 am
content: Quote from: dssence on February 15, 2014, 02:48:53 amIn concept, the hinged panel over the current and voltage controls can be a "safety feature" to prevent accidental changes in your settings, in practice the recessed knobs plus the hinged door will quickly become a nuisance.

author: dlt123me
author_rank: Newbie
timestamp: February 24, 2014, 07:35:25 am
content: Quote from: dlt123me on February 22, 2014, 04:42:40 amI hate bumping this post, but could someone answer the question of .5Amp. Is that too small of amperage for electronic board work? I am too new to the electronic field to know for sure.I am looking at a used PS that has the above specs. Are these good specs for electrical board work?Thanks,Dennis

author: TMM
author_rank: Frequent Contributor
timestamp: February 24, 2014, 08:30:48 am
content: It's hard to say if 0.5A will be acceptable for your uses to be honest. Most of the time i'm playing with a circuit on a breadboard, it is drawing <0.1A. That said it can be useful to have a powersupply that can provide a few amps once you graduate from just powering a handful of components on a breadboard :p. Two channels at 15V, 2A is probably what i'd go for at a minimum.The negative supply is so you can have a split supply using channels 2 and 3. This is commonly used when working with AC signals that oscillate above and below ground/0V - e.g. audio signals. You can normally do this on any supply that has floating outputs by connecting the +V of one channel to the -V of another channel. The -V of the former channel effectively becomes your negative rail and the +V of the latter is the positive rail. Where the outputs are connected together you use as your ground/0V reference.By the manufacturer specifying that Channel 3 is a negative supply and Channel 2 is positive you can infer the +V of channel 3 is permanently internally wired to the -V of Channel 2.

author: dlt123me
author_rank: Newbie
timestamp: February 24, 2014, 09:06:05 am
content: Thank you TMM. I was wondering if the .5 was too small. From my research, most have at least 2A - 5A on average.I found a nice used HP, but think I might have to forego this purchase. Here is a link to the eBay ad if anyone is interested...HP / Agilent E3630A STD, 35W, Triple Output, 6V, 2.5A & ±20V DC Power Supply:http://www.ebay.com/itm/280981692175Dennis

author: bench_knob
author_rank: Regular Contributor
timestamp: February 24, 2014, 12:03:51 pm
content: Quote from: dlt123me on February 24, 2014, 07:35:25 amHey,Personally I would not go out of my way to buy such a power-supply. No, all the output levels have too small a range, in my opinion. And the +-20V, at .5A what good is that?Personally I'd skip over that power-supply.I've been fiddling with electronics a long time, and frankly, there are times when one needs a killer monster power-supply and lots of times when ya need something small. Life is variable and so are the needs for a power-supply through time. If you are gonna being fiddling with electrical gadgets for any period thats one thing, but if you are gonna do it and then put it on a shelf to never or seldom visit again, well screw it, get a specific cheapie for the application at hand. Otherwise, don't get small range output power-supplies for general purpose usage.Currently I have in my personal lab around five or six power-supplies?, two that are homebrew variable linears (transformer and pass transistors):1.2 ~ 24Vdc @ 2A1.0 ~ 50Vdc @ 3AThese were too small for many of my projects over the years.I also have three commericial power-supplies (I actually have owned bunches of power-supplies over the years, but I don't know what happened to them? They cometh and goeth, hah! Like they sprouted legs and walked off!)My supplies:1 x HP6291 : 0 ~ 40Vdc @ 0 ~ 5.0A, constant Voltage & constant current, linear (old but excellent)1 x HP6632A : 0 ~ 20Vdc @ 0 ~ 5.0A, const Volts & const current, linear (also excellent)1 x Elenco XP-581: 2 ~ 20Vdc @ 3.0A, regulated: + & - 12Vdc @ 1.0A, regulated: +5.0 Vdc @ 3.0A, regulatedThe Elenco, ($75 US new), which I've used quite a bit before I found the utility of the InterNet & eBay for better equipment acquisition, I have never used the three fixed outputs for anything in over 15 years. These days, all I use are the two HPs. They handle everything, oh, and I forgot that I bought a Chinese power-supply recently. Its only real value is that its fairly small and practically (because it's actually quite heavy due the monster transformer on the inside) light-weight in comparison to the HPs, which are veritable boat-anchors. The eBay Chinese power-supply is an Arksen 305D,which specs say:0 ~ 30Vdc (upper Voltage sags at 5Amp loads) constant voltage0 ~ 5.0Amps, constant currentAnd it has a dual Voltage and Current seven-segment digital output display, but the DVM circuit isn't too well calibrated, so I always check the output using my bench Fluke Digital-Volt-Meter (DVM). But its an ok power-supply, which you might consider, and I think I paid, $69 + free shipping for it.So, in today's era of electronics, I'd certainly entertain a multiple variable constant Voltage and constant current linear power-supply, and one that has a bit of muscle too. You never know when ya gotta test drive that big ol' honkin DC motor for some gadget or another or maybe test a surplus aircraft landing light, etc. So,0V up to 30 or 40 Volts is a good Voltage range, and0A up to 5Amps is also good,But today's microcircuits require fairly tight regulation of small magnitude Voltages, so the power-supply need vernier range adjustment granularity, and the ability to easily dial-in values such as 2.15 or 3.30, etc. Also, if you buy something and it happens to have a digital readout, besure to check its calibration before using it. Its a bummer when the internal readout doesn't match the power-supply's output!!There's a guy on eBay who sells an inexpensive DVM calibrator gadget. It is quite useful and has paid for itself a number of times. I always double check my power-supply outputs on often expensive loads.Good luck and have fun,bench knob

author: Rigby
author_rank: Super Contributor
timestamp: February 24, 2014, 01:24:27 pm
content: Well, there's use enough for 500ma power supplies for them to be made by the truckload for years and years.It depends entirely on what you want to do, however. If you want to light a bajillion RGB LEDs, then no, a 500ma supply won't do. If you want to power an arduino & GPS shield, then yeah, a 500ma supply is likely to be way more than you'd need. You wouldn't deploy a finished project with a bench supply, of course.Used HP supplies are abundant on eBay and if you know a bit more about what kind of projects you plan to work on, we can gladly help you pick a supply, I'm sure.Here are some I would look at if I had any spare money for more power supplies at all. Mmm more supplies. More gear. Aaaaaah someone help me.http://www.ebay.com/itm/HP-6214C-POWER-SUPPLY-0-10-VDC-0-1-AMP-W-METER-NICE-/231162349798?pt=LH_DefaultDomain_0&hash=item35d25988e6http://www.ebay.com/itm/HP-Agilent-6284A-DC-Power-Supply-Opt-011-0-20V-0-3A-/310878649967?pt=LH_DefaultDomain_0&hash=item4861cfbe6fIf you know you're going to be doing a lot of 5V stuff at higher currents then this one may be worth your attention (no current limiting on this one, though):http://www.ebay.com/itm/HP-6384A-Power-Supply-4-5-5-5-Volts-0-8-Amps-DC-S165-/301105752647?pt=LH_DefaultDomain_0&hash=item461b4d2a47Supplies like this one can be wired up so that you can combine the amperage or voltage of each supply into a single output:http://www.ebay.com/itm/HP-6227B-DUAL-DC-POWER-SUPPLY-0-25V-0-2A-/251459701549?pt=LH_DefaultDomain_0&hash=item3a8c2a8b2dPretty much everything you need is available. Let us know what kind of stuff you wanna do. If you don't know, that's fine too. Search this board and look for things folks have done, and see if anything happens to be of particular interest to you.

author: rdl
author_rank: Super Contributor
timestamp: February 24, 2014, 06:20:33 pm
content: Hmm, that 6227B covers a lot of ground. Looks like it would be a great first power supply. 0-50 v at 2 amps or 0-25 v at 4 amps or +/- 25 v at 2 amps. I could use another power supply, too bad I don't have enough money in my PayPal right now.

author: Rigby
author_rank: Super Contributor
timestamp: February 24, 2014, 07:17:08 pm
content: Quote from: rdl on February 24, 2014, 06:20:33 pmYes, it does, and I am in the same boat as you. I do have two HP 6286A power supplies, though, which can be strapped together to track, and outputs combined either in serial or parallel, which gets me 0-40V and 0-20A. Actually now that I think about it, I still want the 2227B, anyway.

author: dlt123me
author_rank: Newbie
timestamp: February 24, 2014, 07:53:27 pm
content: Bench_knob, Rigby, thanks for the excellent feedback. I just want a good general power supply and I'm going to follow the wisdom here and not get trapped into getting the newer Chinese made units. Some really good advice being voiced around here.As for the surplus aircraft landing light statement, that gave me a good laugh. I don't think I will be doing something like that... but you never know.Thank you all so much. I'm glad I joined this board.Dennis

author: don.r
author_rank: Frequent Contributor
timestamp: February 24, 2014, 08:08:39 pm
content: Others to consider:HP 3236B / 3237B - old school but low power, fixed current limitHP E3630A - more modern but not cheapPower Designs TP325 / TP340 - beast but will lastthere are many, many others.

author: Franz Zinn
author_rank: Contributor
timestamp: August 08, 2015, 05:07:59 pm
content: Quote from: pickle9000 on February 09, 2014, 11:54:35 pmI know this is a old thread but I just noticed it has an error. The CSI3005X5 is Linear Power Supply and not an SMPS. You can see it has a larger transformer inhttp://hackaday.com/2014/03/05/bench-power-supply-constant-current-ez-set/