Help needed, helping a beginner friend get set up with basic test equipment..... - Page 1
Forum section: electronics / testgear

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 09, 2025, 08:38:34 am
content: So, in a complete departure from what I usually play with, I've been asked by a co-worker to help find some basic beginner test gear so she can set up a little mini-lab for tinkering with some projects.Nothing too crazy, stuff like interfacing to a video game controller via an Arduino to simulate button presses, or playing with the usual ebay/aliexpress modules, Arduino, Raspberry Pi, etc... Not too much into the actual circuit and PCB design at this stage.The short list of equipment is the usual:- Soldering iron (will get a basic Hakko from Akihabara in Tokyo)- Handheld Multimeter- Lab PSU- Oscilloscope (this is lowest priority on the list)Then the usual bits and pieces like jumper wires, breadboard, etc etc, which is available cheap in Akihabara so no problems there.Now, if you ask me about higher end gear, I got no problems. But when it comes to entry level stuff, I have no idea...I'm sure she doesn't want to spend on a 3458A and 2GHz Tek scope etc....So, can anyone help with some suggestions for entry level Multimeter, PSU and Oscilloscope?Lower price is better, but value for money and ease of use is important.I was leaning towards just getting something from Uni-t for the meter? Just because I have had good experiences with them in the past. But anything with a traditional range selection rather than the new 'fully automatic' smart meters.I have no idea about cheap PSU's, but something 2 channel (so she can supply 5V and 3.3V simultaneously etc) or two cheap single channel PSU's that can supply a couple amps with a relatively clean and smooth output and an output on/off button would be perfect.For the scope, an entry level thing is fine. I would have given her one of my spare TDS220 scopes if I hadn't sold them off a few months ago... What's the new hotness in entry scopes these days?

author: Aldo22
author_rank: Super Contributor
timestamp: May 09, 2025, 09:40:04 am
content: Do you have a budget in mind?There is something in almost every price range, it just depends on what you want to spend.So for $600 you can get something better than for $200, but even that is possible.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: May 09, 2025, 09:41:57 am
content: As to Lab PSUs have a look at the Korad range. Just recently bought a U203.Use this for powering various notebooks (minus their power supply bricks) coming in for repair.

author: tautech
author_rank: Super Contributor
timestamp: May 09, 2025, 09:53:07 am
content: A Fluke 106 is a dependable DMM with sufficient basic functionality for the hobbyist.

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 09, 2025, 10:33:10 am
content: Quote from: Aldo22 on May 09, 2025, 09:40:04 amI'll check to see if she has a number in mind. For now cheap is good (but not toooo cheap....)I'll check out the Korad PSU, they look to be about what's needed.. but Fluke might be a little more than the budget allows, maybe.. Will check as above.

author: tunk
author_rank: Super Contributor
timestamp: May 09, 2025, 11:23:53 am
content: There's also the Fluke 101 (Minimum DC range is 6V, andno current ranges). If it's only low voltage DC, then most$10-15-20 meters from aliexpress/ebay should do.List of cheap, handheld scopes:https://www.eevblog.com/forum/testgear/portable-oscilloscopes-list/

author: Aldo22
author_rank: Super Contributor
timestamp: May 09, 2025, 11:42:28 am
content: Quote from: TERRA Operative on May 09, 2025, 08:38:34 amDo you mean “mini lab” in the sense of physical size, as in the attached picture (see clothespin as a comparison).These are scope, PSU, DMM and soldering iron. Everything fits in one drawer.Is it important to you that the equipment lasts a long time, or is it just a quick, inexpensive start?P.S. As an Arduino power supply, you can also start with these:https://www.aliexpress.com/item/1005007150637607.html

author: Fungus
author_rank: Super Contributor
timestamp: May 09, 2025, 11:58:23 am
content: I don't know the budget but look for a Fluke 18B+ or a Hioki multimeter.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 09, 2025, 01:25:57 pm
content: Since she works only with low voltage I would think a Fluke is not a good choice. I think something has better functionality but about the same price as the Fluke 10x series. I guess some of the Brymen.

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 09, 2025, 02:27:05 pm
content: For size, small is good, but it doesn't have to be so small that functionality or user experience suffers.It will be used for a cheap start and a stepping stone to more capable gear if she decides to pursue more hardware projects, so spending too much now isn't what she wants to do if it can be avoided. However, things cost what they cost, so (mostly) trouble-free is wroth a few extra coins just so she can concentrate on making without having to fight her gear.Whatever we end up getting, we wouldn't want to get some crap that has known issues and bugs like some cheaper brands. Where an inexperienced user will get confused with red herrings that pop up, not knowing that the issue is a bug or quirk before spending hours chasing ghosts...Hence why I'm asking here, I'm hoping to get ideas and personal experiences to find a decent-ish set of cheap beginner gear that won't cause too many headaches.Thanks all for the recommendations so far, I'm taking a look and getting some ideas.Keep the suggestions coming!Quote from: Aldo22 on May 09, 2025, 11:42:28 amYep, I'll get some of those for her breadboard for sure. I use them too and they are really handy.

author: Grandchuck
author_rank: Super Contributor
timestamp: May 09, 2025, 02:48:32 pm
content: For the cost, one of the inexpensive testers ....

author: Aldo22
author_rank: Super Contributor
timestamp: May 09, 2025, 02:58:29 pm
content: Quote from: TERRA Operative on May 09, 2025, 02:27:05 pmAll right, then I'll give you my personal tips.For the case described, theZoyi ZT-225is pretty much "bang for the buck".As a small "Arduino" power supply, I recommend theFNIRSI DPS-150It is quite precise. A second DMM for the ampere measurement is often not necessary.However, this requires a power source of some kind, e.g. a PD charger or a battery pack.It is more difficult with the scope.Perhaps a scopemeter could be an option to start with, e.g.:DSO3D12orZT703SBut you would need to know more about the requirements.These are just a few ideas, I'm sure there will be many more suggestions.

author: AVGresponding
author_rank: Super Contributor
timestamp: May 10, 2025, 07:55:10 am
content: Given it's Japan, I'd take the opportunity to try and find local brands at decent prices. Hioki would be my first choice for a handheld DMM.For a PSU, how are local prices for ADCMT?I'd also guess an LA might be more useful than a scope? No shortage of those, from the cheap USB powered stuff through old Sony-Tektronix 318's etc, to modern stuff from Yokogawa etc.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 10, 2025, 10:13:00 am
content: Hello TERRA Operative,Quote from: TERRA Operative on May 09, 2025, 08:38:34 amPrefer a linear power supply. An easy way to identify those is to check their weight : for a vanilla one channel 0-30V 3-5A (ballpark < 100 bucks), 3 to 5 kg means linear PS. 2 kg or less probably applies for a SPS (*).Try to find a review on YT in order to confirm the low level of output noise.(*) Of course, some quality lab PS in the 300-1200 bucks budget feature a first switching stage followed by a linear stage. In that case, the weight test fails

author: Aldo22
author_rank: Super Contributor
timestamp: May 10, 2025, 02:33:43 pm
content: Quote from: AVGresponding on May 10, 2025, 07:55:10 amI'm sure Hioki makes good professional devices, but it really has nothing to do with “entry level”.The cheapest Hioki that can measure current costs over 200€.Even Fluke has more to offer in the "entry level" range.

author: HKJ
author_rank: Super Contributor
timestamp: May 10, 2025, 02:41:22 pm
content: Why has no-one talked about Brymen?Get the BM2257 and a serial interface, it is a safe and competent multimeter and with the serial interface you can log data from it. A new EEVBlog video about that is ready.

author: Aldo22
author_rank: Super Contributor
timestamp: May 10, 2025, 03:05:22 pm
content: Quote from: HKJ on May 10, 2025, 02:41:22 pmMaybe because the brands that come to mind under “entry level” are Uni-T, Zoyi, Owon, Habotest etc. rather than Fluke, Brymen and Hioki etc..Just a guess.

author: HKJ
author_rank: Super Contributor
timestamp: May 10, 2025, 03:14:48 pm
content: Quote from: Aldo22 on May 10, 2025, 03:05:22 pmBut then you look up in the tread and see both Fluke and Hioki mentioned.I got the BM2257 some days ago and that meter is packed with functionality, it is not like Fluke where some functionality is often missing (6 current range, two mV range for both AC and DC, temperature, capacity).

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 10, 2025, 05:50:32 pm
content: Hioki, Advantest, Yokogawa, etc are all premium brands with prices to match, unless we find something second hand (which is perfectly fine!)I don't think Brymen is easy to get in Japan without shipping (I haven't seen it around, but then I haven't been looking for it).. Aliexpress has cheap shipping for cheap brands, but shipping from elsewhere can be pricey.

author: HKJ
author_rank: Super Contributor
timestamp: May 10, 2025, 06:14:31 pm
content: Quote from: TERRA Operative on May 10, 2025, 05:50:32 pmEEVBlog ships around the world and some other Brymen dealers also do that. Maybe you can find a reasonable shipping price from one of them.I like Hioki, I have the DT4282 and it is a very good meter, but for a cheaper good meter Brymen wins.I also has a Kyoritsu KEW1062, it is mostly the same as YOKOGAWA TY720.For both of these meters I have written reviews:https://lygte-info.dk/info/DMMReviews.html

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 10, 2025, 06:16:05 pm
content: Quote from: HKJ on May 10, 2025, 03:14:48 pmBrymen entry model is theBM231available forabout 80 EUR.For 'entry level' I would rather suggest brands like'UNI-T', 'Peaktech' and othersfor a price below 50 EUR or even 30 EUR.

author: HKJ
author_rank: Super Contributor
timestamp: May 10, 2025, 06:27:47 pm
content: Quote from: timeandfrequency on May 10, 2025, 06:16:05 pmYou can easily find cheap entry models and they work fine on a bench. The disadvantages with entry level is lifetime (Switch may not last that long) and protection (That is not a issue at low voltages). Entry level generally have good precision.A meter like Brymen can handle 230Volt into the ohms range without any issues (Specs. says they can handle considerable more than that), with entry level meters it is a maybe.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 10, 2025, 06:53:37 pm
content: Hello HKJ,Quote from: HKJ on May 10, 2025, 06:27:47 pmI can only agree with you.As you undercore, an 'entry level' meter might not last 25 years, is not ironclad, and probably won't survive to mechanical torture or HV spikes.This is nothing else than the bare definition of 'entry level', as I imagine most of the forum readers share and understand (*).(*) and for sure, TERRA Operative who is really experienced in TE use and repair is among those. TEK scopes have no secrets for him.

author: Aldo22
author_rank: Super Contributor
timestamp: May 10, 2025, 07:08:41 pm
content: Quote from: HKJ on May 10, 2025, 06:27:47 pmThat can happen, but it doesn't have to.They also last for years. I have a 15 year old €10 multimeter which still works perfectly.And at that price, it's really not that important.Quote from: HKJ on May 10, 2025, 06:27:47 pmZoyi ZT-225 can do that too:https://youtu.be/UIml3TYDomE?t=311Quote from: HKJ on May 10, 2025, 06:27:47 pmYesterday I discovered avideothat tests the ZT-225 against a Fluke 5500A calibrator.It looks pretty good. (See attached screenshots).

author: HKJ
author_rank: Super Contributor
timestamp: May 10, 2025, 07:19:29 pm
content: Quote from: Aldo22 on May 10, 2025, 07:08:41 pmIt is not really the total failure of the switch that is the main problem, it is that sometime you get unreliable measurements due to the switch. I have seen that frequently when using cheap meters, a quick turn of the range switch usually fixes it.Quote from: Aldo22 on May 10, 2025, 07:08:41 pmInput circuit with dual big PTC (or PTC+resistor) and VDR compared to one small PTC and nothing more, there is a significant difference in their handling of overload (And that is mostly in ohms and capacity ranges). But this do not really apply when used on a bench with voltages below 30V, the issue first appear when measuring higher voltages especially if there is some energy behind the voltage.

author: Aldo22
author_rank: Super Contributor
timestamp: May 10, 2025, 07:35:11 pm
content: Quote from: HKJ on May 10, 2025, 07:19:29 pmI've heard of this before, but it's never happened to me.Nobody claims that these cheap meters are as durable as the expensive ones, but for the case at hand they are probably sufficient.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 10, 2025, 09:52:53 pm
content: Quote from: TERRA Operative on May 10, 2025, 05:50:32 pmI which case I think it's a good idea to buy used quality made in Japan meters. Since know meters you can determine for her if the meter is in good condition. I guess the situation in Japan is the same as USA where Brymen doesn't sell in Japan.

author: AVGresponding
author_rank: Super Contributor
timestamp: May 11, 2025, 08:10:37 am
content: Quote from: Aldo22 on May 10, 2025, 02:33:43 pmbuy once, cry once, as the saying goes.No mention of current capability in the OP, butIdidspecificallysay, "to try and find local brands at decent prices", and that "Hioki would be my first choice for a handheld DMM", andnotthat they would be myonlychoice.I would also point out to those arguing about durability wrt hv on the input, that the ability to manage 230VAC in resistance mode in a country that uses 100VAC is less relevant than what happens when someone tries to measure the resistance of a relay coil, while it's being switched on and off, without a snubber network.

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 11, 2025, 09:13:14 am
content: My friend won't be going anywhere close to mains voltages... She will be sticking to logic level and DC voltages to maybe 24V maximum for motors and the like.So any discussion of 230V (which doesn't exist in Japan anyway) is moot.She isn't going to pay the price for premium brands, she doesn't even know if she will continue with electronics at this stage or stick with software. So a low cost to dabble is all she wants to spend, as long as she isn't buying complete crap...I do like the look of the Zoyi ZT-255 meter linked before, I'll check it out a bit and see.

author: nctnico
author_rank: Super Contributor
timestamp: May 11, 2025, 11:50:28 am
content: Quote from: TERRA Operative on May 09, 2025, 10:33:10 amWhen on a budget, I'd get a Korad PSU. Just be sure to buy a fully linear PSU. The noise pushed into the outputs of a switching PSU can obscure measurements and can put a novice on the wrong track while trying to check a circuit.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 11, 2025, 12:33:55 pm
content: I don't know if they would ship to Japan but this power supply seems quite inexpensivehttps://www.amazon.com/Adjustable-Quick-Charge-Overcurrent-0-30V-0-10A/dp/B0CN989377/ref=sr_1_1_sspa?crid=20WJHQVDBMS8O&dib=eyJ2IjoiMSJ9.pXch1yDAJnHAQqMHoyvZID7LdJZz_N1t4EpcvbEiMMn5w8v-KZheZ2p_pRDwTRR7DAogLI9H6XHbeZ1ouOO82e1ebC6y4YPmU5hzfViGu0b3FiK1QrzMnLGeHpDH9GEo0WoKCp_nJfI7JbHaZGunuJysi6vEBwl6nZeiZ8V_jbbnHG-C6qplNU4kzmVaXESU2guXju4KKgYEppsAK0D6lRgNhUKvPyyFLuW_h2CsH5g.1N3FRP1v93Z1z2hSoozPMH54bytq-UAvvZN-1FmnegY&dib_tag=se&keywords=12v%2Bdc%2Bbench%2Bpower%2Bsupply&qid=1746500851&sprefix=12v%2Bdc%2Bbench%2Caps%2C169&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

author: Fungus
author_rank: Super Contributor
timestamp: May 11, 2025, 02:00:10 pm
content: Quote from: TERRA Operative on May 11, 2025, 09:13:14 amIt's usually good to say that in the first post.Quote from: TERRA Operative on May 11, 2025, 09:13:14 amZoyi are among the best "cheapo" meters. Do they sell them in Akihabara?The full range is here:https://zotektools.com/products/

author: robert.rozee
author_rank: Frequent Contributor
timestamp: May 11, 2025, 02:07:59 pm
content: for tinkering with small stuff a couple of ultra-cheap 3.5 digit manual ranging DMMs are great, with the one caveat that the modern ones are so light that they skate around on the desk. it is a pity no one makes a DT830-style meter that is just atinybit better:- all current ranges on their own socket,- no transistor tester,- powered by 6x AA cells,- in a bench meter format.some other opinions:- get your friend a half dozen or so wireless breadboards - they cost next to nothing.- also a couple of packets of jumper leads (crocodile clips at each end), but replace the crimped copper-plated steel wires with soldered decent quality copper wires.- a couple of USB to TTL serial converters - handy for talking to GPS receiver modules, etc.- a selection of AA battery holders - a super easy way to power small things and keeping them isolated.cheers,rob :-)

author: Aldo22
author_rank: Super Contributor
timestamp: May 11, 2025, 02:37:19 pm
content: Quote from: TERRA Operative on May 11, 2025, 09:13:14 amThere's simply no good reason not to buy a ZT-225 with the requirements description you have.It may cost $15 more than a very basic meter. But for the difference you get one that leaves almost nothing to be desired for the Arduino hobbyist.However, you have to be aware that it is relatively large and heavy. But it won't fall off the table and with 3xAA batteries it runs “forever”.

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 11, 2025, 02:52:37 pm
content: Zoyi aren't sold in Akihabara, but shipping is free from the official Zoyi store on Aliexpress, so that's no problems.The ZT-225 is now on the short list.I discovered that I have a HP E3611A in my pile of stuff here, which Ithinkis working. That'll sort one PSU out, pending testing, which is good.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 11, 2025, 03:54:46 pm
content: Hello BeBuLamar,Quote from: BeBuLamar on May 11, 2025, 12:33:55 pmYes, these are the new cheapos we see everywhere. Appealing at first sightbut it's a SPS.Outputs probably as much voltage noise as power. Acceptable for makers and other DIY experiencers.Probably not a good choice to fulfill TERRA Operative's requirement. The HP E3611A he dug outwill do it for sure : linear, not to powerful (30 W), repairable,SM available. That's what we want.It becomes actually difficult to find a new PS having similar features.This oneis a true linear : 4.3 kg 2mVrms (20 Hz - 20 MHz)

author: Anthocyanina
author_rank: Frequent Contributor
timestamp: May 11, 2025, 05:38:53 pm
content: i would recommend the analog discovery 3 + one of those 20$ multimeters, and one of those korad power supplies. (and the power supply would be only if she plans to do higher power and higher voltage than what the AD3's supplies can do, so she might as well skip the power supply at first while working with sensors and LEDs and the usual beginner arduino projects)the AD3 has a good logic analyser, a good pattern generator, it can decode basically any digital protocol, it has 2 oscilloscope channels, 2 waveform generators, positive and negative low power power supplies up to 5V(positive and negative 5V so you could do up to 10V combining them). the software is great and you can set up the interface for whatever you're working on at the moment: digital logic? bring up the logic analyser and pattern generator only. want to see how the digital signal looks like in the analog domain? add the oscilloscope to the screen and hook it up. doing op amp stuff? bring up the power supplies, wave gen and scope.the AD3 is plenty for arduino and on its own it's basically a full basic lab the size of your palm. the support digilent offers is great. if you suggest a feature and it's reasonable enough, they'll reply a few days later with a link to download the new waveforms beta with that feature implemented.it also has a really good resale value in case she decides to not do electronics again, and much easier to store and sell a single small thing than a bunch of separate instruments.i have good dedicated benchtop instruments but i still mainly use my AD2 if what i'm working on is within its capabilities

author: adam4521
author_rank: Regular Contributor
timestamp: May 11, 2025, 07:17:45 pm
content: But the AD, if well featured, is not especially low cost. I think there is something to be said for getting a bench oscilloscope, for the tactile drive and to be able to ‘see’ the circuits easily. When I use my Pico oscilloscope, I use it for its features, not its ergonomics.The usual recommended oscilloscopes from Siglent and Rigol might look pricey to an uncertain beginner but the investment is secure I think with a resale market that wants these.At the lower end I think Owon seem to ‘do what they claim’ but the Achilles heel with those low priced machines - even if you don’t need any decoding or fancy trigger features - is short memory depth.

author: nightfire
author_rank: Frequent Contributor
timestamp: May 11, 2025, 08:21:02 pm
content: Ok, so the specs are something like:- will work at voltages <50V- mains will not be the main part of work- work mainly done on breadboard, probably soldering some stuff- gear should be decent and give reliable values, but nothing fancy/industrial professional grade- space probably is limited in Japan, so size does matterThoughts:- Enter the stuff with one decent multimeter, later stock up as you need more or better quality. Sometimes you need more than one DMM.Tips: New stuff in the 50$ Range, like the mentioned zoyi model, or some equivalent Uni-T or Aneng stuff. That is ok to get your feet wet and is not too crappy to use later on. Alternatively some used Fluke handheld from ebay, if that is ok- like the 101 is great value if you do not have to measure Amps. Or, still smaller, some pocket DMM like  3244-60 Card HiTester Pocket Digital Digital Multimeter- 40$ on ebay Japan as new product.- Soldering Iron: This is a "one-shot" to get it right- and therefore it should fit. Hakko is nice, I have myself one. alternatively, if only small stuff gets soldered, she could go for a USB-powered iron like the pinecil oder some things like iFixit soldering station that gots reviewed by Dave:The advantage here might be that it can be powered by an USB-C power supply- those could also be used (when bought at the right sizes and models) to power the rest of the gear, and/or use some frontend to a fixed voltage power supply like:https://www.conrad.de/de/p/joy-it-jt-ps360-labornetzgeraet-einstellbar-0-60-v-0-6-a-schmale-bauform-3203105.html?hk=SEM&WT.mc_id=google_pla&utm_source=google&utm_medium=cpc&utm_campaign=DE+-+PMAX+-+Nonbrand+-+Learning&utm_id=20402606569&gad_source=1&gad_campaignid=20392975386&gclid=Cj0KCQjwlYHBBhD9ARIsALRu09pAZKNqNxL-94TDxR5i--YpiONoqxPsf2jCxVWG9BnifXSbkUcI-CMaAi-DEALw_wcB&refresh=true#productTechDataThose can be powered by standard cheap fixed voltage supplies, like notebook PSU etc. you might get cheap from ebay or recycle from defective notebooks.-scope: Question is here, if the scope only has to check the quality of the signal, or if you have to do precision work- there are lots of el cheapo options available, or use an integrated multimeter/scope solution.Those are also quite compact and should be sufficient to check for signals on Arduino etc. - no need to go for a full size scope like Rigol 1054 or so.

author: nctnico
author_rank: Super Contributor
timestamp: May 11, 2025, 08:39:58 pm
content: Quote from: TERRA Operative on May 11, 2025, 02:52:37 pmThat E3611A looks kind of nice. From my experience a lab PSU should have at least 10mV display resolution for the voltage. For many modern devices the maximum voltage is just a couple of hundred mV above the normal operation voltage. 100mV resolution isn't going to cut it.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 11, 2025, 11:12:31 pm
content: Hello nctnico,Quote from: nctnico on May 11, 2025, 08:39:58 pmYour requirement is more demanding than what TERRA Operative asked for. Hence, prices are not the same.You may find linear PS (or SPS + linear end stage) with mV resolution fromAim-TTI. Also check outthese. If a precise voltage delivery is required,using the Kelvin sense lines is compulsory(*). Prefer the programmable version if it's an option.If one or several additional digit(s) is required (100 µV or better), you need to switch from PS toSMU.Really cool stuff. Significant financial power is adviced.Same gear, but made by thecompetitors.(*) Corollary: small (USB-C or mains powered) PS with mV or even 10 mV display resolution that do not feature Kelvin sense lines is not a good choice. At 3 A, there's a 200 mV voltage drop in the wires that cannot be dynamically compensated. So payng for the extra digit without sense lines is just sqandering your money.

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 11, 2025, 11:28:45 pm
content: When I need precision, I use my Advantest R6161....The E3611A will be mostly powering the usual modules on 0.1" headers for Arduino/Raspberry-Pi/Breadboard stuff and the like, probably through one of the breadboard power supply modules linked to earlier, so super accuracy isn't toooo critical, but if greater accuracy than the PSU display is needed then that's what the multimeter is for.(The E3611A has 10 turn pots, so it's not too bad to dial in)

author: Aldo22
author_rank: Super Contributor
timestamp: May 12, 2025, 11:14:53 am
content: Quote from: nctnico on May 11, 2025, 08:39:58 pmThat's one reason why I like the little DPS-150.You can adjust it in 10mV or 1mA steps and it's amazingly accurate.

author: nctnico
author_rank: Super Contributor
timestamp: May 12, 2025, 11:19:56 am
content: Quote from: timeandfrequency on May 11, 2025, 11:12:31 pmYou are mistaking resolution with precission.The 10mV resolution is needed to see 100mV of precission (which is easy to achieve on a cheap PSU).

author: Fungus
author_rank: Super Contributor
timestamp: May 12, 2025, 09:23:06 pm
content: Quote from: robert.rozee on May 11, 2025, 02:07:59 pmThey do...https://www.eevblog.com/forum/testgear/trashy-meters-redux/

author: David Hess
author_rank: Super Contributor
timestamp: May 13, 2025, 06:11:37 am
content: I would start off with two multimeters, which could be the same or different models.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 13, 2025, 07:03:18 am
content: Hello @nctnico,Quote from: nctnico on May 12, 2025, 11:19:56 amYou asked for 'at least 10 mV display resolution' and never talked about precision. What I suggested are PS that feature mV resolution that totally fulfill the requested requirement, so I don't know what you have to complain.If your are not happy with my suggestion, why don't you do the search by yourself ?

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2025, 08:36:00 am
content: Quote from: Messtechniker on May 09, 2025, 09:41:57 amThe Korad U203 is an SMPS, right?I've looked at the data sheet, but I'm not sure.Why is this not openly communicated?You always have to deduce it somehow via the ripple (≤20mVrms) or the weight (2.5kg).I actually thought KORAD was known for linear PSUs.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: May 13, 2025, 09:21:15 am
content: Yes. But what's the problem? I use it to operate notebookswith missing power brick. And with a diode inserted in the + lineto revive Lion Batteries from deep discharge state. Chargingthese at 0.1 C for 30 mins usually does the trick.The Korad U-series is quite new.

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2025, 09:36:25 am
content: Quote from: Messtechniker on May 13, 2025, 09:21:15 amNo problem. I just had in mind that Korad is known for linear PSUs, so I wasn't sure and the datasheet doesn't say it clearly.Thanks!

author: robert.rozee
author_rank: Frequent Contributor
timestamp: May 13, 2025, 03:00:48 pm
content: Quote from: Fungus on May 12, 2025, 09:23:06 pmah yes, i remember that thread well - it is the one where i posted my 're-imagining' of the DT830:where apart fromremovingranges, just a small electrical modification would be required so that above 75v an over range is displayed.cheers,rob :-)

author: Messtechniker
author_rank: Frequent Contributor
timestamp: May 14, 2025, 06:12:50 am
content: Quote from: Aldo22 on May 13, 2025, 09:36:25 amJust did a noise mesurement on the U 203. Noise (for which bandwidth?)is specified as max. 20 mV.Pumping 15 V into 8 Ohms yielded noise of 0.3 mV with the bandwidthbeing 300 kHz (KS 34454A)100 MHz scope connected in parallel says 6 mV peak to peak at no stable frequency.Sorry for not having any beefier load resistors.

author: Aldo22
author_rank: Super Contributor
timestamp: May 14, 2025, 08:12:42 am
content: Quote from: Messtechniker on May 14, 2025, 06:12:50 amThank you!Looks pretty good, but I think it's very difficult to make comparable noise measurements with different scopes, settings, probes, loads and environments.For me, most of the noise is “in the air”.Ripple is a bit easier to measure.

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 14, 2025, 01:52:33 pm
content: Quote from: Aldo22 on May 14, 2025, 08:12:42 am6mV is not too shabby for an entry level lab SPS.Usual measurement bandwidth for this kind of test is 20 MHz and should be done at nominal output current.Choosing a suitable probe is also required.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2025, 02:09:23 pm
content: Quote from: Messtechniker on May 13, 2025, 09:21:15 amFor those purposes a switching PSU is perfectly fine. But not if you want to measure signals in a circuit. The noise from a switching PSU will turn the trace on your scope in a fat line obscuring any detail. A Korad KD3005D is not expensive and seems to be linear (there is a big transformer inside).

author: robert.rozee
author_rank: Frequent Contributor
timestamp: May 14, 2025, 02:20:28 pm
content: Quote from: nctnico on May 14, 2025, 02:09:23 pmfor those times one needs a 'quiet' power supply, and bearing in mind the OP is helping get abeginnerset up, a good choice is simply a 12v gel cell battery that ends up needing to be recharged once in a blue moon. indeed, today the modern equivalent is a handful of 18650 Li-Ion cells fitted in holders.we don't want to be over-thinking things!cheers,rob :-)

author: timeandfrequency
author_rank: Frequent Contributor
timestamp: May 14, 2025, 03:09:28 pm
content: Quote from: robert.rozee on May 14, 2025, 02:20:28 pmProviding a gel cell 12 V battery to a beginner would not spontaneously be my first choice. At least not without a series 0.3 - 1 A fast fuse. Indeed, the short-circuit current of such a puppy is in the ballpark of 100 A.Unless he/she is found of Electroboom and enjoys experiencing short-circuits, sparks, molten wires and metal vapor deposition.

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2025, 03:16:33 pm
content: Agreed. Having a current limiter is very handy to avoid smoke effects. With a current limit you can power a chip in reverse, burn your finger and swap the supplies. Without current limit, your breadboard goes up in smoke.

author: Aldo22
author_rank: Super Contributor
timestamp: May 14, 2025, 05:16:11 pm
content: Even with batteries, you want to be able to set the voltage and current limit.The DPS-150 can also be operated with batteries.It is not completely noise-free this way, but less so than with the mains adapter.

author: David Hess
author_rank: Super Contributor
timestamp: May 14, 2025, 05:47:26 pm
content: Small batteries like 9 volt batteries are fine. Big batteries like alarm style 12 volt 7 amp-hour lead-acid batteries are a bad idea because their short circuit current is so high. I only use big batteries, or my high current power supplies, when absolutely required for a specific application.

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 14, 2025, 10:41:45 pm
content: We won't be using lead acid batteries, or any batteries for that matter, that's just getting ridiculous now.We have decided on the Zoyi ZT-225 for the multimeter, and have thrown some of those breadboard power supplies mentioned earlier into the cart, along with a breadboard kit (two breadboards on a plate with a bunch of jumper wires and stuff), a couple Arduino Mega's and some cheap electronics kits to practice soldering.For a soldering iron, we settled on a Hakko FX-600 rug burner with built-in temperature control (I used to use one years ago and they are good for a cheap starter iron), in a kit with the brass wool tip cleaner and a stand.Once I have my E3611A all adjusted and tested, that will do for now for the PSU until she outgrows it, with the benefit of being HP, linear and most importantly, free.At the time she outgrows that, she'll be able to figure out what she needs to upgrade to without too much trouble.As for the scope, we decided to not buy one for now, but if she decides that playing with hardware is totally awesome (which it is), something like the Rigol DHO800 or Siglent equivalent looks good. But that is a question for a later time.