Bench power supplies - Page 1
Forum section: electronics / beginners

author: jasonbay13
author_rank: Contributor
timestamp: November 19, 2016, 03:30:10 am
content: I am looking for a bench power supply. finally got tired of trying to find the right battery, wall plug, chinese buck or boost board to just get some volts and amps.i was looking at the BK Precision 1685B 60V as it has a fairly high voltage up to 5 amps, which should be enough for most things.it says it can be hooked to pc for logging and control too.the spec says voltage regulation to 50mv, which is good. but the current regulation is only 100ma? seems a bit inaccurate for something so costly?what would be wrong with something affordable such as the ebayeBay auction: #http://www.ebay.com/itm/Wanptek-KPS305D-0-30V-0-5A-Adjustable-Digital-Switching-DC-Power-Supply-110-220V/371747815944?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D39107%26meid%3D7fce72f723b24080b1947f41d518c21e%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D381030711964looking for suggestions, thoughts. i'd like to have something around the 60v range with cv/cc and cheaper is better, as alwaysp.s. first post here (though not the first time i was mentioned here...), hi all!

author: MarkF
author_rank: Super Contributor
timestamp: November 19, 2016, 04:22:37 am
content: How much do you want to spend?I have a fewHP2616Asupplies from eBay for less than $60 including shipping. I really like their small size. You can hook multiple units in parallel or serial.For most projects, 30V should be more than enough. I'm also looking at the newRigol DP711supply for a little more current. Which I only would have liked to have for one project.

author: jasonbay13
author_rank: Contributor
timestamp: November 19, 2016, 04:38:20 am
content: i like the looks of that rigol, except that i mess with leds sometimes and they often have Vf around 34v.tad bit pricy, too. i'd like to spend no more than $250, and even then i'd prefer around $100.currently the best "bench supply" i got is an atx psu with a lm317 and centech dmm hooked up to it for a max of 14v and not a lot of power, esp. with the small heatsink i got on it.i was thinking about just winding my own transformer for 40v dc to a 317 driving a 2n3055 with a gigantic heatsink. but run into the problem of current control. and even if i can, whats my accuracy? 200ma/mv? at best?

author: Cody Turner OKC
author_rank: Contributor
timestamp: November 19, 2016, 04:54:06 am
content: I just got my first bench psu its a Bk precision 1735A and its 0-30v and 0-3A, honestly i thought i would need double volt and amps before! Now i realise i could get by with half of it, mine doesnt hook to the computer it had some minor problems i troubleshooted and got help on here and fixed within a day. All in all its a nice supply only complaint i have is the course and fine adjustments, the course is way to course, and the fine is okay but only covers about 40mv/ma. Its nice to have the constant current and the current limiting once you figure it all out, just giving a little intel on my thoughts of the BK around the same model! Hope it helps a little bit!

author: MarkF
author_rank: Super Contributor
timestamp: November 19, 2016, 05:13:22 am
content: If you had two HP2616 supplies, you can put them in series to obtain +50V or +/-25V. The only draw back is that they only have a 400mA output (which can be doubled if you put two units in parallel).Also, theTekpower TP3005Tmaybe an option.

author: ez24
author_rank: Super Contributor
timestamp: November 19, 2016, 05:35:54 am
content: If you like Art Decohttp://www.ebay.com/itm/Lab-Power-Supply-3-Outputs-2x-0-32V-1A-0-15V-2-5A-Works-Great-US-Made-/172323366754?hash=item281f45e762:g:4IAAAOSw3xJXo5NvPower Designs Power Supplies are highly respected on this forum. Some members restore them. A lot better than new crap.There are a million posts on them here. They are a work of art.Another idea - place a WTB post here, I bet you could find some good finds here

author: julian1
author_rank: Frequent Contributor
timestamp: November 19, 2016, 05:42:56 am
content: Don't overlook the value of a dual rail supply (or two single supplies) - if you're going to play around with op-amps or audio amplifiers etc.And 60V at 5 amps is a really big! It's easy to see the design trade-offs involved with the 100mA OC resolution - making it a lot less useful for smaller electronics work.I wonder if you could get away with a more general-purpose supply - and then jury-rig something for the high-voltage stuff (custom secondary winding on a toroid + regulator + filter cap).

author: mtdoc
author_rank: Super Contributor
timestamp: November 19, 2016, 06:00:06 am
content: For 60V and 5A on a budget, it's hard to beat the Mastech HY3005 supplies on eBay which can be found for about $200.They give you dual 30V 5A supplies that can be put in series or parallel with a button to give you either 60V 5A or 30V 10A. They also have a 3rd fixed 5V supply. You'll find them under different branding sometimes but they all have the same look - though some have LED displays and some have LCD. Build quality is reasonable for the price but they are not "precision" power supplies by any means. You'll want to use a multimeter to adjust output if you need precision.Here's one under the "Dr. Meter" label on eBayfor $196 with free shipping.

author: NottheDan
author_rank: Frequent Contributor
timestamp: November 19, 2016, 09:04:06 am
content: I just had a linear 305 arriving here yesterday. Working pretty well and it is good enough for my purposes but the lack of control and feedback in the very low current range is a definite annoyance. You also have to keep in mind the switching spikes.

author: ProBang2
author_rank: Frequent Contributor
timestamp: November 19, 2016, 01:06:47 pm
content: What´s about the Korad KA 6005 (D or P)? Not available in the USA?

author: bitseeker
author_rank: Super Contributor
timestamp: November 20, 2016, 12:11:55 am
content: Quote from: ez24 on November 19, 2016, 05:35:54 amYeah, Power Designs made quite a lot of models including some precision ones. Note that some models have constant current operation whereas others only offer current limiting (disables output when limit exceeded).(Un)fortunately, they're kind of addictive. I just added one of these to my collection. 20V, 1.5A, CV and CC, plus etched panel lettering rather than less-durable silkscreen type. Only 150uV ripple.

author: Savetheday
author_rank: Regular Contributor
timestamp: November 20, 2016, 12:30:36 am
content: I think everyone should have one pc power supply converted branch Power supply like thatorsomething more professionalGood Luck!!

author: ez24
author_rank: Super Contributor
timestamp: November 20, 2016, 01:05:25 am
content: Quote from: bitseeker on November 20, 2016, 12:11:55 amThis is the only downside to them. They are just soo pretty.

author: jasonbay13
author_rank: Contributor
timestamp: November 21, 2016, 11:11:52 pm
content: https://www.amazon.com/gp/aw/d/B00G0HAY3U/ref=mp_s_a_1_5?ie=UTF8&qid=1479769537&sr=8-5&pi=AC_SX236_SY340_FMwebp_QL65&keywords=Korad+Technology&dpPl=1&dpID=41ozOi8%2BkeL&ref=plSrchi can see that. 10mv and 1ma accuracy. exactly what i want except lacking pc co trol, which i cant find anywhere.assuming it doesnt blow up like the 3005p did for dave, i think thats would be perfect.p.sp.s. spell check on phpne is imlossi le.

author: bitseeker
author_rank: Super Contributor
timestamp: November 22, 2016, 06:12:02 am
content: For the programmable version, the KA6005P is pretty scarce. The KA6003P is more readily available if you can live with 3A. However, for more flexibility you could get the KA3305P triple-channel power supply and still achieve 60V 5A by configuring channels 1 and 2 in serial. If I had to choose between a KA3305P and a KA6005P, I'd get the KA3305P.http://www.sra-solder.com/korad-ka3305p-programmable-precision-variable-adjustable-30v-5a-dc-triple-linear-power-supply-digital-regulated-lab-grade

author: ProBang2
author_rank: Frequent Contributor
timestamp: November 22, 2016, 10:11:25 am
content: I support the recommendation of bitseeker.If in budget, then go with the KA3305P. It´smuchmore versatile.It is probably the best bang per buck PSU at this time.One step up - and you are in the area of the Rigol or Siglent PSUs (with twice the price).One step down - and you are loosing resolution and functionality (in worst case with an overpriced cheapo).I use a KA3005P since May 2015. (Yes, the same model that is blown up in Dave´s video. But that isa story long time ago, in a country far far away... They had made some board revisions since then and thereare follow-up videos. So this story is like)My experience with this device is good. It has for sure no easy life. Sometimes abused for automotive use (e.g.to load a car battery with 14.8V @ 5A over 24h or to search a randomly occuring short circuit), then usedfor electronics, the output limited to just a few mA. It works well.Unfortunately I have no experience with the KA3305P. The lack of negative threads in this forum should bea good sign. Hence I will probably buy one in the next future.

author: jasonbay13
author_rank: Contributor
timestamp: November 22, 2016, 08:45:17 pm
content: Gonna grab the ka3305p as it seems to have the functionality i need at a not-completely-bankrupting price.should i let you know what i think of it as a beginner with no previous supplies to compare it against?

author: bitseeker
author_rank: Super Contributor
timestamp: November 22, 2016, 09:49:06 pm
content: Of course! Photos of the insides are always welcome, too, if you're feeling mischievous. Otherwise, don't jeopardize your warranty.

author: jasonbay13
author_rank: Contributor
timestamp: November 28, 2016, 10:57:43 pm
content: Got it in the mail today. messing with the settings still, but thought i'd let you know about first impressions.the layout and display seem pretty nice. all 5 memory buttons retain memory, but either keeps what was last used on that memory slot, or can only store after being set while on it.accuracy is well enough. i was seeing variation +- ~4mv between single volt increments, have not checked cc accuracy.heavy unit, rather deep too and fits perfectly on my bench.voltage and current control is kinda awkward since you have buttons for ch1 or ch2 each switches between the ch's voltage or current to use with the two knobs, which is voltage on left knob and current on right knob. but if you have ch 1 voltage blinking and try using the current control, it wont work until you either push ch 1 again to get current or push the current knob, which makes me wonder why there are two wheels when only one is needed.this is about 15 minutes into playing with it...pictures of insides might happen someday but first i really need to prioritizing on getting rid of some stuff. *smalltext* i'mnotahoarder *smalltext*

author: jasonbay13
author_rank: Contributor
timestamp: December 21, 2016, 04:43:59 am
content: it seems i've run into a problem, not sure if it is something i did but in M1 i cannot lower the current value for ch2. i can make it higher but not lower. ch1 works normally. and if i set it to serial or parallel i can lower it on ch2. M2 works fine.

author: bitseeker
author_rank: Super Contributor
timestamp: December 21, 2016, 08:00:34 pm
content: Quote from: jasonbay13 on December 21, 2016, 04:43:59 amI'm not sure I follow. Are you saying that you cannot store into memory location M1 a current value for Ch2 that's lower than the one that's already stored there?When set to serial or parallel, which channel is master, 1 or 2?

author: jasonbay13
author_rank: Contributor
timestamp: December 21, 2016, 10:54:56 pm
content: when i have the supply on M1 preset i can change the voltage and current up AND down for channel 1, but channel 2 only allows me to change voltage up and down and current up but NOT down.i can turn the wheel up, and it increases, turn the wheel down and nothing happens. though it does keep the display in set mode (blinking) as if i were actually adjusting it. all the other M2-M5 work as expected.i can get it to go back down by using serial/parallel, unsure as to which is slave/master.

author: Aeternam
author_rank: Unknown
timestamp: December 22, 2016, 08:06:16 am
content: First make sure you're not in serial or parallel mode.Then try changing the voltage on CH2, then change the current setting. That should help. This is a weird interface bug I experienced once or twice; I can't remember what I did to regain control of the current setting but I'm pretty sure it involved fiddling with the voltage setting.

author: jasonbay13
author_rank: Contributor
timestamp: December 22, 2016, 11:27:27 am
content: I went to take a video, so I set up M1 and M5 for some leds to demonstrate, but ended up somehow transferring the problem from M1 to M5. Then after a little bit more messing with the knobs and buttons the problem went away completely.I think it might have something to do with switching between M1-M5 while the selection is still blinking (in set mode)

author: xani
author_rank: Frequent Contributor
timestamp: December 22, 2016, 12:18:55 pm
content: I've got KORAD KA3005D-3S (dual 30V/5A with serial/parallel mode + constant 5V/3A) some time ago and I'm very happy with it (only problem was a bit shoddy power switch but that is easy enough to replace), but it seems it is not available anymore? Did they stopped producing it ?Current limit goes down to few mAs which is very nice as that already saved one board from releasing some smoke

author: bitseeker
author_rank: Super Contributor
timestamp: December 23, 2016, 05:15:33 am
content: Quote from: jasonbay13 on December 22, 2016, 11:27:27 amThat is a weird problem. Maybe a firmware bug where it gets into an unexpected state? Glad you got it to finally behave. It'd be nice to know at least the steps to fix it when it acts up.

author: bitseeker
author_rank: Super Contributor
timestamp: December 23, 2016, 05:21:42 am
content: Quote from: xani on December 22, 2016, 12:18:55 pmIf I remember correctly, the KA3305D is the model that came after it. The "-3" got moved to the beginning of the model number and the extra 0 went away. 3-channel, 30V, 5A -> 3305.

author: jasonbay13
author_rank: Contributor
timestamp: January 21, 2017, 10:21:26 pm
content: so after using it a while, its still working fine. use it almost every dayi wanted to mention that the cables it comes with are not so great. sure they work, but are of ebay quality. i measured over half a volt drop just through the wires at 5A. i made up a pair and soldered the connections. at the same 5A i got less than 50mv drop.

author: Vtile
author_rank: Super Contributor
timestamp: January 21, 2017, 10:31:23 pm
content: Oh... Didn't notice you have your new PSU now.

author: james_s
author_rank: Super Contributor
timestamp: January 23, 2017, 05:32:21 am
content: I've always built my own power supplies, they make good beginner projects and they are useful for all manner of other projects. These days you can take the easy route and reuse an old laptop power brick or similar and one of any number of regulator modules you can buy from Chinese suppliers these days.

author: pete1zed
author_rank: Contributor
timestamp: May 16, 2019, 07:22:57 am
content: I bought the TENMA 72-10495 (AKA Korad KA3005D-2S) dual channel power supply, but there are many issues with it. To help others understand it's limitations before buying it (or to help work out its insane user interface after purchase),here is the manual, marked up with corrections and warnings about bugs in the user interface and behaviour:https://ufile.io/drsjx09jThis applies to models:- TENMA 72-10495 (Korad KA3005D-2S): 30V-5A x 2 Channels- TENMA 72-10500 (Korad KA3003D-2S): 30V-3A x 2 Channelsand probably also- TENMA 72-10505 (Korad KA3003D-3S): 30V-3A x 2 Channels & 5V-3A x 1Important notes to avoid damage:● Do not allow power supply to sink current. Use diode when charging battery.● For sensitive circuits, see Avoiding overshoot and excessive in-rush current :○ Inside the power supply, there is a capacitor near the output terminals for stability. The current limiting and over currentprotection (OCP) cannot control current from this capacitor.○ There is some overshoot on turning a channel on.○ There is a spike when turning mains off while the channel is on.● In parallel mode, connect load to CH2 (right hand) channel. (When mains power is turned on, the power supply defaults toindependent mode, and CH1 to whatever voltage and current settings are in CH1 memory recall M1, with the load turned off.Therefore, avoiding CH1 could prevent mistakenly applying wrong settings to the load.)● OCP and OVP do not work in serial and parallel modes.● If you recall a CH2 memory in SER mode, only CH2 is updated from that memory and only CH2 turns off. At this time, CH2output terminals have up to -1.2 V (i.e. reverse polarity) on them, with a short circuit current of up to -2.8 A.This also happens when the channels are independent but you have wired them in series.● When using the power supply in SER mode, or wired in series, you may have to ensure the supply is working in CV mode toavoid instability.Important notes to avoid confusion:● There is a small negative voltage and current when the load is switched off (50mV, 100 uA)● OCP/OVP:○ CH2 OUT LED stays on after CH2 OCP/OVP trip disconnects the load.○ OCP and OVP do not work in serial and parallel modes○ CH2 OVP/OCP buttons also control CH1 OVP/OCP○ CH1 OVP/OCP buttons only control CH1 OVP/OCP○ The OCP and OVP LEDs apply to whichever channel last updated them. Pressing either the OVP or OCP button updates both theOVP and OCP LEDs with that single button push.● An OCP/OVP trip for one channel does not trip the other channel

author: 1NFR4R3D
author_rank: Newbie
timestamp: May 13, 2024, 12:44:12 am
content: Hi! Sorry for necroposting.Quote from: pete1zed on May 16, 2019, 07:22:57 amCould you please upload this file to some other website? These folk seem to want $8/month from anyone who wants to access it!