Small Efficient Power Supply - Page 1
Forum section: electronics / beginners

author: tony3d
author_rank: Frequent Contributor
timestamp: July 11, 2021, 07:06:48 pm
content: Hi, I’m slightly above a beginner, and I have limited space on my desk. I was wondering if anyone knows about this space saving little power supply? It uses GAN transistors from the looks of it. It obviously is a switch mode supply, and I can’t find any real tech review about noise, or turn on spikes. Does anyone have any real info on this little thing. It would be perfect for me, but I don’t want something that will destroy my projects. It’s made by ToolkitRc, and the model is a P200 it’s supposedly 30v 10a. Thanks!

author: ledtester
author_rank: Super Contributor
timestamp: July 12, 2021, 05:34:12 am
content: Interesting device.On page 15 of theuser manualwhich you can find onhttps://www.toolkitrc.com/P200has these specifications:I wonder what they mean by "adjustment period" -- perhaps that's the time it takes for it to change to a new voltage setting.The 1 ms response to over-current is kinda in the same ballpark as the Korad KA3005 according to this test:Bench Power Supply Testing, Homemade vs. Korad KA3005 vs. LongWei LW-K3010D - TheStuffMadehttps://youtu.be/RdT-xWC4h4k

author: brucehoult
author_rank: Super Contributor
timestamp: July 12, 2021, 06:00:51 am
content: As you've no doubt already found, there are a few reviews on youtube and regular web and everyone seems to like it.Several of them have checked the output voltages with a multimeter but I haven't seen any check with an oscilloscope which is a bit unfortunate.As the various reviewers note, you can buy a higher capacity bench power supply for less money, but much bigger and clunkier, and without many of the nice UI features including usage graphs etc.I've never had an adjustable power supply with current limiting, so I'm tempted. It's cute.Dave needs to torture test one for us.

author: ataradov
author_rank: Super Contributor
timestamp: July 12, 2021, 07:20:03 am
content: I tried to find any reviews that would actually check the performance, but it looks like they seeded review units to RC people, and they don't have proper equipment to test. And to be fair, they don't really care for fast response times for their typical use cases.It is pretty compact, it would be nice to see it put through a real test.

author: viperidae
author_rank: Frequent Contributor
timestamp: July 12, 2021, 11:55:27 pm
content: It looks like it is only rated for 100W output when plugged into the mains. For 200W output, you need to supply it with DC.That would explain some of its compact size, the AC switch mode side is only rated for 100W.

author: brucehoult
author_rank: Super Contributor
timestamp: July 13, 2021, 01:10:41 am
content: "looks like"? It literally says that in big letters on the front panel. :-) :-)But would such a small and light device not be using a switch mode DC to DC converter *all* the time?

author: skander36
author_rank: Frequent Contributor
timestamp: September 05, 2021, 01:46:02 pm
content: It can output max 178 W on AC.For DC I didn' test it. ON USB type C it is recognized as SuperFast Chager with PD PPS protocol displayed.- Min. - 1 V / 0,5A- Min setting step is 50 mA/mV (adjustable until 500 - 50/100/150/200...500)It makes audible noise under load and it has an instability when output is on, that makes internal temp to rise to 45C. This trigger the internal fan that makes internal trafo or inductors (or ther components?) to make an annoying beep until the fan stops.There is someone that can confirm this ?Quite noisy but understandable as this primary scope is charging LiIon accu's for RC models.

author: iMo
author_rank: Super Contributor
timestamp: September 05, 2021, 02:05:54 pm
content: People made the "red led" test with their PSUsSet voltage to 30V and current limit to 20mA, then connect a red led - whether it survives..

author: skander36
author_rank: Frequent Contributor
timestamp: November 13, 2021, 07:44:55 am
content: Not so long life ...After only a short of output wires (they just touched one or two times for a fraction of seconds) the source has cracked. Pics attached.I understand that this can be a defect on only my source , but ... be aware. No output protection on short circuit ...Bangood initially said that will send me a power board, but after that they changed and say that will refund me.The buck convertor part is still alive and can be used with DC (12V).Can anyone take a picture of their power board and tell me what component (U2) is that wtih a hole in it?Thank you very much!

author: brucehoult
author_rank: Super Contributor
timestamp: November 13, 2021, 09:08:29 am
content: The diagonal part of that vertical trace in the center of the board doesn't look healthy.

author: skander36
author_rank: Frequent Contributor
timestamp: November 13, 2021, 10:32:32 am
content: Yes, it is "exploded" .This board look clean just because I cleaned it. It was all black from smoke. The internal space is very limited.Some diodes I also found dead ... but I thnk it can revive ... I hope

author: CaptDon
author_rank: Super Contributor
timestamp: November 13, 2021, 01:19:16 pm
content: Cheap Chinese junk designed for charging the batteries of radio controlled model cars etc. A simple short blew it up, evidence of a crappy design. Most definitely NOT suited for the hobbyist / experimenter workbench!!! If you intend to use the supply with radio equipment you probably want a linear supply which will be heavy and run warm with little or no R.F.I. If you intend to do non-radio related projects then a 'switcher' style supply would be lighter with higher current capability. You should have a really large 'stabilizing' capacitor available if you have projects that demand peak spike current which could be 5 to 10 times the rated current of the supply. Switcher power supplies go into current limit and fall on their face when subjected to spike currents, linears with their large output ripple filtering capacitors can handle spikes very well!! I have a 120,000uf @ 75vdc capacitor as my 'spike energy source' with a 10 amp fuse in series with it. That capacitor when charged to 75vdc (locomotives are 64vdc / 72vdc nominal) will burn holes in sheet metal and blow traces right off of circuit boards when things are amiss!!!

author: skander36
author_rank: Frequent Contributor
timestamp: November 15, 2021, 08:49:00 pm
content: Keep cool. It was aquired just for play, for how it look. I'm not with the RC's ...I have a plenity of other sources on my bench, but people on this forum love to revive electronics.I'm just asking here, maybe one of the people who have this power source find time to make a photo of the power board.Thanks in advance!

author: brucehoult
author_rank: Super Contributor
timestamp: November 15, 2021, 10:01:55 pm
content: Quote from: CaptDon on November 13, 2021, 01:19:16 pmUh ... the whole point of having a "maximum current" setting on the front panel of these things is you DON'T WANT the power supply to exceed that current setting if the load "demands" more by, for example, having a short circuit.Having a huge capacitor on the output defeats the entire purpose.As someone said: set the voltage to 30V and current limit to 20mA, then connect a red LED and see whether the LED survives.The aim of a good experimenter's bench power supply is that the LED *does* survive this, because the power supply drops the voltage to limit the current quickly enough that significant energy doesn't go into the LED. Your huge output capacitor is the opposite of this -- you'll be picking bits of the LED out of the ceiling (I exaggerate).I have no idea whether good bench power supplies (or this one) actually pass this test. It would sure be nice if they did.The power supply itself blowing up if the output is shorted seems very bad.

author: CaptDon
author_rank: Super Contributor
timestamp: November 15, 2021, 10:35:47 pm
content: Don't have to have that surge capacitor online if not needed, sadly our locomotive stuff has run currents around 1 to 5 amps and inrush at 70+ amps sometimes. So on SMPS supplies they sit there and go twitch, twitch, twitch, twitch, run. Unless I have the stabilizing cap online. I put stackable banana plugs on my cap. The old Sorensons (we have 1, 2 and 3kw versions) all have current limiting AND huge output capacitors. Sometimes you need REAL safety current limiting, and sometimes you need to simulate two 32 volt railroad batteries in series, each 3ft long, 2.5 feet wide and 1.5 feet tall capable of not dropping below 50 volts when drawing 1500 amps on a cool morning, but you don't have room in the lab for the batteries, or the safety assholes won't let you have them in the lab "Because they say so!!!". I'm not sure if a .1uf cap charged to 75vdc would kill an LED or not, I have seen a lot of 'high quality' SMPS units with a .1uf across their outputs, guessing for noise reduction. But then again, not to many of the dudes on this board have supplies upwards of 30-50 volts anyway. 72vdc on a running locomotive gives you a nasty bite or sting when the weather is dry and your hands are dry, but it will rock your world in your hands are damp/wet or you have a nasty unprotected cut on your hands, which seems to happen a lot when working on locomotives!!

author: skander36
author_rank: Frequent Contributor
timestamp: November 16, 2021, 10:48:49 am
content: As I said in a post above : this source allow a minimum current of 0,5A - 500mA, so stop with that LED test ...

author: Larsinka
author_rank: Newbie
timestamp: February 21, 2022, 02:13:41 am
content: Hey man, here's a picture of mine. Hope it helps. Seems to be the main GAN fet which isn't really cheap but still cheaper than buying a new PSUNavitas NV6117

author: skander36
author_rank: Frequent Contributor
timestamp: February 21, 2022, 10:51:30 pm
content: Hi Larsinka!Thank you very much for your effort.This chips is quite cheap. I found it on Digikey on around 3 Euro.https://www.digikey.ro/ro/products/filter/pmic-comutatoare-de-distribu%C8%9Bie-a-energiei-drivere-sarcin%C4%83/726?s=N4IgTCBcDaIHIEMBuBLALggzgAjgNQDYBGIgdhAF0BfIAWhen I contacted Toolkit, they offered to send me powerboard for 52 $ but shipping from China to Romania and customs cost me almost as a new one, so yes is cheaper to repair.

author: 350D
author_rank: Newbie
timestamp: April 25, 2022, 03:07:31 pm
content: My P200 exploded after few seconds working on 16V/2A powering my flight controller with faulty esc. Same chip destroyed.Seller send me replacement part for 14$I've expected a bit more from bench power supply for this money.

author: Fraser
author_rank: Super Contributor
timestamp: August 29, 2022, 03:51:30 pm
content: I needed a compact variable power supply for charging batteries and quick power tests on equipment. This little unit appears one of few choices in the market that are truly compact. At the price it seemed more expensive than its larger cousins but you expect to pay a little extra for the size reduction. It is interesting to see that some owners have suffered failures when the u it is shorted or over-loaded ! Not a great start but may be bad luck / early firmware ? I note that the firmware has had some revisions to address some issues including the current limit timing and minimum constant current boundary.I ordered a P200 unit as it’s small size is important in my case and I have plenty of larger Lab Power Supply units for more serious work. I looked at the Miniware power supply but it’s design did not appeal and it appears overly expensive.To those who suffered failures of the P200, did you manage to repair it ? Mine is coming from a respected UK shop so I do have a warranty if it fails in the first year.Fraser

author: radiolistener
author_rank: Super Contributor
timestamp: August 29, 2022, 04:11:49 pm
content: Quote from: Fraser on August 29, 2022, 03:51:30 pmI don't recommend to buy compact power supply, especially Chinese, especially switching mode...It can burn your load, can make fire, can shock you or even kill... This is dangerous, not reliable and very noisy (both - sound and RFI).The good power supply is linear one. Large size and heavy weight == more good quality, because heavy transformer can run at higher power and large dimensions with large radiators leads to better cooling to avoid overheatingI recommend you KORAD KA3005P, if you want better noise floor, try to find linear power supply with no digital electronics (with analog Voltage indicator and mechanical potentiometers).

author: strawberry
author_rank: Super Contributor
timestamp: August 30, 2022, 06:54:12 am
content: R220 seems too small 1V / 0,22 = 4,5A / ~2 = 2,3A * 150Vdc = 345WNo wonder they removed heatsinks after revision 1,2

author: Fraser
author_rank: Super Contributor
timestamp: August 30, 2022, 09:46:33 am
content: Strawberry,Interesting comment. Have you reverse engineered that part of the power supply ?I will be using my P200 in very non demanding roles. I just need a neat compact variable power supply to quickly test kit or put some charge into discharged batteries to wake them up from their sleep. I have decent quality linear and switch mode programmable power supplies in my lab but they are not very compact for having on my Home Office desk in our spare room. I often just need a particular voltage with reasonable current capability, normally less than 3A. I think the P200 should cope fine in that role.In one of the reviews I noted a comment that the noise levels on the output of this power supply are higher than would normally be expected for a lab power supply. But this is not really a lab power supply, more a general purpose variable supply for less demanding roles. I might look at improving the power rail noise levels with additional filtering though.Interested to hear more about that resistor and it’s value that you have mentioned. What is the story on the heatsinks please ?Fraser

author: Fraser
author_rank: Super Contributor
timestamp: August 30, 2022, 10:29:36 am
content: Teardown video of the P200….https://youtu.be/ju0rDFaFBMMI am wondering which Switching controller they use on the AC to DC mains input supply. Maybe some modifications will make that input power supply a little bit more robust !Fraser

author: strawberry
author_rank: Super Contributor
timestamp: August 30, 2022, 03:59:52 pm
content: maybe flyback(resonant)Navitas NV6117 maybe short circuit protection too slow for 1,8ºC/W 0,25Ω conduction losses ~1,3W + current shunt ~1,3Wseen many blown ~20W SMPS with same ~0,22Ω

author: Fraser
author_rank: Super Contributor
timestamp: August 30, 2022, 09:54:48 pm
content: From looking closely at the pictures in this thread, I think the switching controller ESD to drive the GaN transistor is the On-Semi NCP1342. I shall study its datasheet but already note that this controller is quite smart in terms of its protection capabilities. So the serious “melt-downs” of the aN transistor and PCB traces puzzles me somewhat. If the current sense resistor is indeed the wrong value that is a schoolboy error surely ?https://www.mouser.co.uk/datasheet/2/308/NCP1342_D-1509449.pdfFrom the datasheet….• Overload/Short−Circuit Protection: The NCP1342 implements overload protection by limiting the maximum time duration for operation during overload conditions. The overload timer operates whenever the maximum peak current is reached. In addition to this, special circuitry is included to prevent operation in CCM during extreme overloads, such as an output short−circuit.I believe the switching controller is the NCP1342AMDCD version that is fully detailed in the datasheet.

author: Fraser
author_rank: Super Contributor
timestamp: August 30, 2022, 10:58:38 pm
content: A useful video detailing how to calculate the correct primary circuit current sense resistor in a SMPSUhttps://youtu.be/wEueXBIgQrEThe NCP1342 has a current sense input threshold of 0.8VFraser

author: Fraser
author_rank: Super Contributor
timestamp: September 01, 2022, 07:23:59 pm
content: The P200 power supply arrived todayHaving given it a good test with 100W load for over 30 minutes, I have failed to kill itIt looks like I got a good one but time will tell.Other tests have confirmed that the P200 output supply rail is a little more noisy than I am used to with lab power supplies, but for my needs it is perfect. This unit is Sooo smallFraser

author: radiolistener
author_rank: Super Contributor
timestamp: September 01, 2022, 11:10:49 pm
content: Quote from: Fraser on September 01, 2022, 07:23:59 pmand so dangerous...There is a sense to use electrician rubber gloves and protective glasses with such PSU and check fuses for mains before use. Also keep fire extinguisher near this PSU...

author: Hundleton1
author_rank: Contributor
timestamp: November 12, 2022, 12:35:37 am
content: Well mine blew tonight as well rather unexpectedly on power up with a load. Anyone have a clue what’s going on here with these. Thinking of rebuilding but need to check everything else first.

author: ono
author_rank: Contributor
timestamp: February 19, 2023, 06:03:43 pm
content: I have recently returned my P200 that I initially bought beginning of the last year. P200 size and nice UI were major selling points for me. Also for some experiments I am usually to lazy and also a bit afraid to use more expensive Siglent SPD3303X-E. Almost from the very beginning I was receiving "Input spike!" errors occasionally. I thought it has something to do with regulation of my mains. But then when I made really nice silicon shielded coords for my Pinecils I learned that it cannot power this switching portable soldering iron, because its AC-DC simply does not like the switching and it is AC-DC causing "spikes" that then 2nd DC regulation module complains about. I managed to reproduce this "spike" with 20V and 5R power resistors, that otherwise should work perfectly fine since 4A 80W is below max of this unit.So I realized this power-supply cannot do anything, but simple battery charging tasks. Also the minimum CC setting of 500mA is absolutely too high to do anything more sensible, such as checking the circuits slowly raising current limit. So in the end it is far from something I'd recommend. Also my ToolkitRC never responded to my ticket regarding "Input spike!". Since I bought it from really good seller in Switzerland, I was able to return it with full money refund with minimal questions asked.Reading and watching some other reviews I now use Gophert PPS-3205 32V 5A switching power supply as my 2nd bench unit. It is a little bigger than P200, but still very small / portable. It is completely passively cooled, has reasonable ~40mVpp noise on load (as for a switching unit). And ~$60 with shipping price is ok. It works well, although obviously the it nowhere near with 1-2mVpp of my Siglent linear PS. It also clicks a bit when used with Pinecil. I suspect loose coils may be the culprit. So I will keep using USB-C plugged to wall adapter for soldering.