Variable Power Supply question - Page 1
Forum section: electronics / testgear

author: timwolf
author_rank: Contributor
timestamp: September 14, 2021, 04:38:59 am
content: I'm rather new, but I've been an electrical engineer for about 2 years, I need to get a power supply in order to conduct more advanced learning. I've been looking at various variable power supplies in the 0-30V, 5A range (though I would love a 0-60V range), and I find that a lot of people complain that they are too noisy, the cheapest I've found with my limited skill set of test equipment knowledge is the "Siglent Technologies SPD3303X-E Triple Output Power Supply" since it offers 2.5 output points @$390(which is about $156 per output point). I'm looking for something that has low noise and is bang for your buck for a young engineer.P.S. question:I'm looking to upgrade my multi-meter, the current one I have is a cheap automotive multi-meter and I saw the "ANENG AN8008" being reviewed in one of the Evvblogs videos, would this be an appropriate multi-meter to upgrade under $50?

author: tautech
author_rank: Super Contributor
timestamp: September 14, 2021, 04:58:37 am
content: Quote from: timwolf on September 14, 2021, 04:38:59 amFYI SPD3303X-E are quiet and at low loads you will barely know it's ON.They can be setup in series or parallel mode with just the press of a button to give 60V @ 3A or 30V @ 6A.The only thing one must be wary of is back feeding the outputs beyond their max reverse voltage as specified in the datasheet. A beefy series diode offers all the protection required if needed however the displayed output vs real output will be off by the Vf of the diode of course.

author: bob91343
author_rank: Super Contributor
timestamp: September 14, 2021, 05:01:20 am
content: Save your money and pick up an old one at a swap meet.

author: ledtester
author_rank: Super Contributor
timestamp: September 14, 2021, 05:22:14 am
content: Quote from: timwolf on September 14, 2021, 04:38:59 amWhen it first came out the AN8008 got a lot of attention because it originally cost $20.It's still a decent meter at that price, but if you have more money to spend consider some of the meters in this thread - notably the rebranded UNI-T UT61E:https://www.eevblog.com/forum/buysellwanted/newark-sale-on-many-tenma-brand-meters/msg3650947/#msg3650947The UT61E has been widely discussed on this forum.

author: WattsThat
author_rank: Frequent Contributor
timestamp: September 14, 2021, 05:33:07 am
content: What’s a swap meet ? ;-)Says the guy that has never bought a new power supply in his life. I save my money for the stuff I cannot build or stuff that I can get on the cheap and repair/restore.The AN8008 is an okay meter for the price. Small and light if you like that in a meter. Nice low current ranges but an annoying power off beeper. They can be found for $30 and less, shop carefully and watch out for the knock-offs. Some may be rebadged ANENG’s? but I wouldn’t recommend it for mains usage, it’s bench use only for mine. I doubt it would survive well in a tool bag without a full case. BTW, the stock probes suck, not uncommon for cheap meters.

author: sotos
author_rank: Frequent Contributor
timestamp: September 14, 2021, 06:02:07 am
content: Look at these.Also delivered from USA and UK.https://www.banggood.com/RIDEN-RD6012-RD6012W-USB-WiFi-DC-DC-Voltage-Current-Step-Down-Power-Supply-Module-Buck-Voltage-Converter-Voltmeter-60V-12A-p-1687705.html?rmmds=detail-left-hotproducts&cur_warehouse=CN&ID=6290063And a smaller one.https://www.banggood.com/RIDEN-RD6006-or-RD6006-W-Digital-Control-Switch-Adjustable-Power-Supply-DC-Stabilized-Power-Adapter-Buck-Module-Monitoring-Power-Supply-p-1587151.html?rmmds=myorder&cur_warehouse=CN&ID=6279943

author: rvalente
author_rank: Frequent Contributor
timestamp: September 14, 2021, 04:07:16 pm
content: Check the vintage HPs from the 70s and 80s, workhorses that are always reparable like 62xx, 63xx and 64xx

author: mawyatt
author_rank: Super Contributor
timestamp: September 14, 2021, 05:01:19 pm
content: You are an EE so likely more into electronics than the usual hobby types.The old HPs are very good supplies if you can find one and repair it. Don't even consider any kind of switch-mode power supply if output noise is a concern, stay with linear supplies only.If you can't find any old HPs, then the Siglent you mentioned and tautech verified is an excellent choice. These are not only low output electrical noise, but also low audible noiseOne of the really important uses when involved in development, not typically mentioned, is how good is the current limit at low ranges, and how much energy can the supply deliver into a temporary short, mis-wire, or just a dangling lead that brushes across the Vcc/Vdd lineSh#! happens and this feature alone is worth considering if you plan on developing things that involve expensive ICs, it saved my arse a few times alreadyThis is just one of the many reasons we are using these Siglent supplies for serious development work.Disclaimer we have 3 of the Siglent SPD3303X-E, all working with our ongoing research project. I'm using all 3 now to supply +-60V, +-7V, +5V (digital), another +5V (analog) and 2.2V. These are stable enough to use as a decent stand-in voltage reference in a pinch.BTW if you decide on the Siglent, the Saelig distributor here is US has a EEVblog discountBest,

author: nctnico
author_rank: Super Contributor
timestamp: September 14, 2021, 06:29:23 pm
content: Quote from: timwolf on September 14, 2021, 04:38:59 amLook at the GW Instek GPP serieshttps://www.gwinstek.com/en-global/products/detail/GPP-Seriesas well. Unlike the Siglent PSU you found, this series has a numeric keypad which IMHO is essential on a digitally controlled PSU in order to set it up quickly & conveniently. A twisty knob needs a lot of turns which becomes tedious quickly. If I needed to buy a bench PSU today, I'd probably end up with a GW Instek GPP series; it really ticks all the boxes. It is not in the datasheet but it seems the GW Instek GPP series has a dual range current measurement circuit so it can measure low currents with greater accuracy.For your 'primary' power supply you better stay clear from the switching ones. Their output noise easely swamp small signals you are trying to measure. I don't agree with getting an older HP/Agilent model. Many older power supplies don't have an accurate readback of current and/or voltage which means needing to use a DMM. More modern bench PSUs have much more accurate (often 4.5 digit DMM accuracy) readouts which makes life a lot easier.

author: timwolf
author_rank: Contributor
timestamp: September 18, 2021, 11:26:33 am
content: Quote from: sotos on September 14, 2021, 06:02:07 amI looked at them it looked great, but the fact that the once you connect it to Wifi it immediately contacts a Chinese IP address is a bit concerning, I saw them at around $160 to $200

author: LaryPant
author_rank: Contributor
timestamp: September 18, 2021, 01:03:03 pm
content: Hi,I would suggest looking into the KORAD KA3005P or multiple of them. Have a look at this video:it compares 3 of the aforementioned power supplies to a Rigol DP832, which is similar to the Siglent model you mentioned, and the winner is definitely the KORAD KA3005P.For the same price of the Siglent SPD3303X-E you can almost get four KORAD KA3005P, which would give you much more flexibility as well as a higher current and voltage range by combining them in series or parallel. Or you can start with just buying one or two and add the rest later if you need it.I have two KORAD supplies on my bench myself and I am very happy with them.LaryNote: You may miss out on some more advanced features by running several KORAD KA3005Ps instead of a signle 3 channel PSU.

author: rodak
author_rank: Newbie
timestamp: September 29, 2021, 03:50:17 pm
content: Quote from: mawyatt on September 14, 2021, 05:01:19 pm"Saelig" distributor? Is that different from TEQuipment.net?Considering the SPD3303C myself, glad I found this thread, thanks for all the info!

author: rodak
author_rank: Newbie
timestamp: September 29, 2021, 03:52:36 pm
content: Quote from: timwolf on September 18, 2021, 11:26:33 amWhoa! What the heck is WiFi for on a bench power supply? And it contacts a Chinese IP? No thanks! (They looked a little iffy to me anyway, I generally try to avoid that sort of stuff)

author: sotos
author_rank: Frequent Contributor
timestamp: September 29, 2021, 05:59:29 pm
content: Quote from: rodak on September 29, 2021, 03:52:36 pmDon’t buy the Wi-Fi module that costs 5 to 10 dollars if you don’t need it. With the extra module you can connect your smartphone and do extra things. Read the sellers page about the Wi-Fi module.

author: Bad_Driver
author_rank: Frequent Contributor
timestamp: October 31, 2021, 10:48:25 am
content: I have two of this Riden 6018 switching power supplys. They are a lot bang for the bucks because I bought them before the EU increased the import taxes and VAT for Alieuxpress items this summer. (about 120 Euro per device)Current and voltage control and limits are near display values (+/- 1 or 2 counts)They are good for heavy works (checking LED lights, digital circuits with high power demand, power amplifiers) but very very noisie!I also use an 30years old STATRON analog PSU (var. 2x0…20V, 1A, 1x 0…30V, 2.5A, fixed 5V) 4A without fan for anything else. Unfortunately it tends to oscillating with digital load.Since I got a Amazon gift card from my employer last month I will now go with an additional Siglent SPS3303x-e.You can never have enough PSUs on your bench!

author: Bad_Driver
author_rank: Frequent Contributor
timestamp: November 10, 2021, 10:31:57 am
content: I use my SPD3303X-E now for some days. User interface isn't so intuitive in the beginning. This changing between "Fine" and the arrow keys and the rotating knob is weird.The "improvement" went well. I like the form factor, it is not as deep as the Rigol PSU (1:0 against RIGOL - my other evaluated choice) and it fits to my other Siglent devices.The binding posts are not the best, some plugs work, others not (1:1 against RIGOL). I help myself with some Aliexpress found clamps and use them for my SDL1020 as well (see photo).Noise is only measurable with my Low Noise Amplifier (v=1000).Performance is very good. Accuracy of voltage and current is near the limits of my old Fluke 45 (4.5 digit DMM), to seedifferences I need my 6.5 digit DMM (I relate this to my improved SPD with the additional digits).Current limits are precise down to 0.5 mA, very good! It seems that the setting value is closer to the real value than the shown"measured value" but differences are in the range of +/- 2 digits. Display is great (2:1 against RIOGOL) ! Parallel and serial modes are intuitive and helpful.All 3 sources are independent, no joint grounding (3:1 against Rigol)What is strange? Only a "Quick guide" available, ok PSU usage is not so complicated. Graph is only for fun, no way for time settings, history etc.What do I miss? Why there is no calculation for "Ws" or "mAh" during charging, it is DC, it's a simple multiplication! Or have I not found it??The software is a nightmare, Siglent, ask some kids at school to make it better. It looks like a mid-90s DOS-application!It seems that every Siglent product follows another GUI idea for hard- and software.Since I don't know the RIGOL software I can not judge about.Hope that C.J.S. finish his work on a definition of the SPD3303X for "TestController".https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/msg3787664/#msg3787664My decision for the Siglent PSU was mainly influenced by the form factor and my membership in the "Siglent fan boy club"

author: C.J.S.
author_rank: Contributor
timestamp: November 10, 2021, 11:07:21 am
content: Quote from: Bad_Driver on November 10, 2021, 10:31:57 amFYI, I consider definition file "Siglent SPD3303X.txt" attached tothis messageas finished.QuotePeople who find the form factor less important can also have a look at theOwon ODP3033(3A per channel) or ODP3063 (6A per channel). These Owon's are circa 7cm deeper than the Siglent SPD3303X / SPD3303X-E but have the advantage that channel 3 is fully variable between 0 and 6V, and the price is significantly lower than the Siglent.

author: Bad_Driver
author_rank: Frequent Contributor
timestamp: November 10, 2021, 02:43:52 pm
content: I have to admit that the OWON PSU looks not that bad!I hadn't it on the screen since I was told to buy @ Bezos little mail shop due to a non expected gift card from my employer.The 6 Amps version from OWON looks promising!Thanks for your SPD3033X definition for TestController! What is the last version?

author: Fungus
author_rank: Super Contributor
timestamp: November 10, 2021, 02:53:01 pm
content: Quote from: timwolf on September 14, 2021, 04:38:59 amThe AN8008 measures OK but it's a bit flimsy.For a little bit more money the Aneng AN870 measures even better and is alotmore robust.PS: Get some gold plated probes while you're upgrading. They can be had for about $2 in the same place they sell Anengs and make a huge difference.

author: Fungus
author_rank: Super Contributor
timestamp: November 10, 2021, 02:56:21 pm
content: Quote from: rodak on September 29, 2021, 03:52:36 pmJust out of curiosity: Would it be OK if it contacted an American IP address?

author: C.J.S.
author_rank: Contributor
timestamp: November 10, 2021, 03:41:18 pm
content: Quote from: Bad_Driver on November 10, 2021, 02:43:52 pmLast version of my SPD3303X definition is v1.0.1. This version is attached to the forum message that I referred to in my previous message. It will also be included in the next release of HKJ's TestController.

author: Bad_Driver
author_rank: Frequent Contributor
timestamp: November 11, 2021, 08:08:37 am
content: Quote from: Fungus on November 10, 2021, 02:56:21 pmAll my different bench devices and my Internet-of-Things appliances are blocked in the router against WWW. It's easy to flash a lot of cheap Chinese IoT stuff with Tasmota or ESPeasy.And my inbound/outbound traffic is filtered with "Pi-hole". I'm always surprised how many devices wanna call home (Samsung TVs every second). My mobile devicesare outdoor always connected via WireGuard VPN with my home net and so internet traffic is filtered as well. Nothing of this is magic or voodoo but it makes sense to put some efforts in it."Pi-Hole" and "WireGuard" run an a simple Raspi3. I have a 1GBit line, so BW is no problem.Calling home is only allowed to my kids.