Help me choose a power supply  - Page 1
Forum section: electronics / testgear

author: mrjeff51
author_rank: Newbie
timestamp: April 17, 2023, 11:43:44 pm
content: I know this question is probably posted a lot but none of the other posts were helpful. I am looking to purchase a linear single output power supply that can provide at least 30v and 5A, looking to spend under $400. I've been reading a lot of reviews and am getting even more confused. I've looked at the Korad KA3005P and Tekpower Tp3005T but the reviews on Amazon are all over the place.The siglent spd3303x-e seems like a good choice except the outputs would probably have to be daisy chained to get 5A.Not looking for DYI. What would you guys recommend? Preferably something not Chinese made but would be okay if it was decent quality.

author: ataradov
author_rank: Super Contributor
timestamp: April 17, 2023, 11:55:44 pm
content: Korad KA3005P is an excellent power supply. I don't know that I would trust Amazon reviews when it comes to electronics lab equipment. A lot of people there are clueless.

author: tautech
author_rank: Super Contributor
timestamp: April 18, 2023, 12:01:14 am
content: Quote from: mrjeff51 on April 17, 2023, 11:43:44 pmSPD1305X meets your spec however SPD3303X-E provides additional channels and versatility albeit no single channel provides 5A, Parallel mode provides 6A but only to 30V however 60V @ 3A is available in Series mode.https://siglentna.com/power-supplies/spd1000x-series-programmable-dc-power-supply/

author: jwet
author_rank: Frequent Contributor
timestamp: April 18, 2023, 12:15:49 am
content: You've got a pretty strong budget for this supply- you can get a reasonable 150W supply for about $100. Be careful and read the specs carefully- I see some supplies say "Linear Type" etc- I don't know what that means really. You can also look at the weight- if its truly a 150W fully linear supply, its going to have to have 15 or so pounds of copper and iron for a 60 Hz transformer. I'd also look at the manual- look a the ripple and noise, a linear supply shouldn't any ripple or noise beyond 120 Hz first order. Looking at what's available from the usual suspects- for my money, I like the Owon P4305- its about $250 well within your price target, has nice high resolution volts and current displays, digital programming and a nice color display. Owon is known brand and has support and firmware updates, etc.Your last sentence about Chinese made is humorous- it's ALL chinese even from the big guys!

author: coppice
author_rank: Super Contributor
timestamp: April 18, 2023, 12:18:21 am
content: Quote from: ataradov on April 17, 2023, 11:55:44 pmI wouldn't trust an Amazon review to even be about the product you are looking at. A large number contain complaints about features the product doesn't have.Be careful when looking up places offering the Korad supplies. When I was looking at supplies recently I found various pages, such as this Amazon UK listinghttps://www.amazon.co.uk/KORAD-KA3005P-Programmable-Precision-Adjustable/dp/B00FPU6G4E?th=1, where the KA and KD models are muddled up. They are very different products.

author: jwet
author_rank: Frequent Contributor
timestamp: April 18, 2023, 12:41:52 am
content: Amazon reviews are a joke, agreed but if there are enough quantity, you can read between the lines and get some idea of the weaknesses- every once in a while some truth will out.The one real positive about Amazon for me is absolutely hassle free and cost free returns on anything I've ever had a problem with. I'm in the US and a prime member, I don't know if its as easy in other parts of the world, but its painless here. I don't even have to repack it- I can bring it to a local "pack and post" type of shop and they give me a receipt and take care of it. Amazon processes the return that day.

author: BillyO
author_rank: Super Contributor
timestamp: April 18, 2023, 02:16:52 am
content: If you want the 3-channels and 5 amps, the Korad KA3305P/KD3305P are great great choices. You can get up to 60V @ 5A or 30V @ 10A. A bit less money than the Siglent SPD3303X-E too but I do like the Siglent a lot. It has a much better display and UI as well as Ethernet connectivity.

author: John B
author_rank: Frequent Contributor
timestamp: April 18, 2023, 02:55:00 am
content: I've got the KD3005P and KD6005P. I have no real complaints, and they'll be fine as a first PSU, but not your only PSU. The method of changing the voltage and current is a little tedious, so I use them where I want a reasonably defined current limit, but don't need to alter much on the fly. When I want to tinker with the values quickly, I use a GW Instek GPE-3323, but it has single turn pots, so comes with it's own quirks. Also the current readout on the KD supplies isn't that accurate, no big deal in most applications, but don't expect too much at the price point.They're also rebranded as Tenma units, so you can shop around your electronic distributor and price compare between models, and even pick them up on special like I did.

author: beatman
author_rank: Regular Contributor
timestamp: April 18, 2023, 03:18:14 am
content: i use rigol DP711 til now perfect.

author: nctnico
author_rank: Super Contributor
timestamp: April 18, 2023, 06:34:33 am
content: I'd give the GWInstek GPP-4323 or one of it's brothers a good look. It has many features that the Rigol and Siglent counterparts don't have. But likely over budget.

author: radiolistener
author_rank: Super Contributor
timestamp: April 18, 2023, 12:26:04 pm
content: I recommend to have two linear power supply. One KORAD KA3005D and second fully analog one, with no CPU and no digital voltmeters (analog linear regulation and analog pointer voltmeter). KORAD is a nice PSU, but if you're debugging noise sensitive device, it's better to use fully analog PSU.

author: Grandchuck
author_rank: Super Contributor
timestamp: April 18, 2023, 12:58:52 pm
content: I have this one and it works well:https://www.jameco.com/z/HY3005D-2-R-Mastech-300W-Dual-Output-Benchtop-Power-Supply30V-5A-30V-5A_301947.html

author: mawyatt
author_rank: Super Contributor
timestamp: April 18, 2023, 01:34:06 pm
content: We have and use the GPP-4323 and SDP3303X-E (have 3). All have the ability to be placed in Series or Parallel mode without any additional external cables/wires, so perform just like a single PS with additional Voltage (60V) or Current (6A). Both have USB and LAN, the GPP also has RS232 interface, and the GPP has 4 independent programmable channels, SPD has 2 independent programmable, and one fixed (2.5, 3.3, 5) channel.The GPP has a unique built-in load capability on 2 channels, the SDP can be user calibrated (the GPP can't) and can be user "enhanced" to an SDP3303X (1mv and 1ma resolution), the GPP has 0.1mv and 0.1ma resolution.The SDP UI is a little more quirky than the GPP but both require a little getting used to. The display screens are the same size, however the GPP screen can be setup in various ways (5 settings), very nice feature!These are what one might consider "Lab Quality" Power Supplies, stable accurate voltage and current settings, low noise, no voltage overshoot, fully programmable, quality build and low fan noise. BTW both types have shown very low drift & noise (GPP < +-1mv long term drift with <80uv SD, SDP <+- 2mv long term drift, <40uv SD @ 10V).The GPP costs ~$760, the SPD ~$400.Best,

author: tautech
author_rank: Super Contributor
timestamp: April 18, 2023, 08:45:53 pm
content: Mike, not sure if you are aware but several SPD3000X/X-E can be placed in series while in Series mode to provide 100's of volts.Datasheet spec allows for any output to be elevated to 500V max above mains ground.I've done it to 120 and I think 300V would be my limit despite what the datasheet says !

author: mrjeff51
author_rank: Newbie
timestamp: April 20, 2023, 04:17:54 am
content: Quote from: tautech on April 18, 2023, 12:01:14 amWhen you say series and parallel mode, is that referencing output 1 and output 2 on a single siglent spd3303x-e or would I need two siglents? Also when in series or parallel mode, will the display show 60v or 6.4amps? Is there button for these modes on the device?

author: tautech
author_rank: Super Contributor
timestamp: April 20, 2023, 04:29:25 am
content: Quote from: mrjeff51 on April 20, 2023, 04:17:54 amThe 3ch SPD3303X-E had Parallel and Series mode buttons on the from panel whereas SPD1305X is a single channel PSU.SPD3303X-E can do 60V @ 3A or 30V @ 6A plus the 3rd channel can still be operative.Have a look at the little GIF on the HQ webpage:https://int.siglent.com/products-overview/spd3000x/The display leaves the operator to do the maths depending on which mode they are using, the reason being several units can be seriesed together for elevated voltages when the instrument wouldn't know how many are in use so the display only shows each channels output in any mode, normal, Series or Parallel.

author: mrjeff51
author_rank: Newbie
timestamp: April 20, 2023, 04:57:23 am
content: Quote from: tautech on April 20, 2023, 04:29:25 amSo on a 3 channel SPD3303X-E I should be able to get 48v @ 3A or 50V @ 5.5 A if I needed to using series or parallel mode?

author: tautech
author_rank: Super Contributor
timestamp: April 20, 2023, 06:41:12 am
content: Quote from: mrjeff51 on April 20, 2023, 04:57:23 amToo easy.I have used 2 units in Series mode for 120V.

author: BillyO
author_rank: Super Contributor
timestamp: April 20, 2023, 05:07:23 pm
content: Quote from: mrjeff51 on April 20, 2023, 04:57:23 amFor 50V @ 5.5A you would need 2 of them.Do yo need 50V @ 5.5A?

author: Electro Fan
author_rank: Super Contributor
timestamp: April 20, 2023, 05:12:15 pm
content: Depends on your budget but for anywhere near $100 I'd go for the Korad KA3005D (unless you need the programmable/PC interface feature, then go with a KA3005P). I have both a KA3005P and a KA3005D; IMO the KA3005D is among the best values you can find for ~$110 (on Amazon or at sra-solder.com). In fact after about 10 years of TEA I'd say for ~$110 the Korad KA3005D is among the best values not just in power supplies, but in test equipment.There are a bunch of Korad threads; here are a couple.https://www.eevblog.com/forum/testgear/bench-power-supply-261782/msg3348756/#msg3348756https://www.eevblog.com/forum/testgear/korad-3005p-calibration/msg4172872/#msg4172872

author: mrjeff51
author_rank: Newbie
timestamp: April 20, 2023, 08:42:04 pm
content: Quote from: BillyO on April 20, 2023, 05:07:23 pmI don't need 50v @ 5.5A. was just curious.I actually bought a Korad KA3005P 30v 5A last week because of this thread. The very next day one of the power adapters for my home security system went out (I didn't know it was a power issue at the time)I pulled out the Korad to check if it was a power issues and wouldn't you know, the power brick was 48v @ 1.25A. The Korad was useless. Thinking maybe the siglent spd3303x-e would have been the better play.

author: ataradov
author_rank: Super Contributor
timestamp: April 20, 2023, 09:07:37 pm
content: Quote from: mrjeff51 on April 20, 2023, 08:42:04 pmWould not it be better to measure 48 V rather than power the system? What are chances that both PSU and the reset of the system is out at the same time?Also, most of that stuff work with less than 48V. 48V is just a PoE standard, so that's what those PSUs are designed for. It is highly likely to work with 30 V just as well.Quote from: mrjeff51 on April 20, 2023, 08:42:04 pmThere will always be a scenario where tools you have are not sufficient. That's just life.