Switching power supply Gopher CPS-3010 30V 10A $0.35/W - Page 1
Forum section: electronics / testgear

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:50:19 pm
content: I have receivedGopher CPS-3010fromFranky.

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:51:06 pm
content: pics

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:53:18 pm
content: pics

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:55:00 pm
content: pics

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:55:50 pm
content: pics

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:56:53 pm
content: pics

author: omgfire
author_rank: Regular Contributor
timestamp: September 08, 2014, 06:57:20 pm
content: pics

author: omgfire
author_rank: Regular Contributor
timestamp: September 12, 2014, 02:22:07 pm
content: I have checked PSU displays with multimeter. Voltmeter is ok. Ammeter is ok above 0.3A, but useless below.Code:Constant voltage with ~40 Ohm loadV set V displayed V at DMM A displayed mA at DMM7.0 7.0 7.00 0.20 163.26.5 6.5 6.50 0.18 151.26.0 6.0 6.00 0.17 139.25.5 5.5 5.50 0.16 127.55.0 5.0 5.01 0.15 116.94.5 4.5 4.51 0.14 104.34.0 4.0 4.01 0.13 92.83.5 3.5 3.51 0.11 81.23.0 3.0 3.01 0 69.72.5 2.5 2.51 0 58.12.0 2.0 2.01 0 46.61.5 1.5 1.51 0 34.91.0 1.0 1.01 0 23.30.7 0.73 0.72 0 16.40.5 0.5 0.51 0 11.70.4 0.4 0.41 0 9.40.3 0.3 0.31 0 7.10.2 0.2 0.21 0 4.70.1 0.1 0.11 0 2.40.0 0.0 0.01 0 0Constant current with ~6 Ohm loadA set A displayed A at DMM V displayed4.9 4.90 4.89 32.04.5 4.49 4.49 29.24.0 3.99 3.99 25.83.5 3.50 3.49 22.43.0 3.00 2.99 19.12.5 2.50 2.49 15.82.0 2.00 1.99 12.61.5 1.50 1.49 9.401.0 1.01 0.98 6.170.9 0.91 0.88 5.540.8 0.81 0.78 4.900.7 0.71 0.68 4.260.6 0.61 0.58 3.620.5 0.51 0.48 2.990.4 0.41 0.38 2.370.3 0.31 0.28 1.74Constant current with ~40 Ohm loadA set A displayed mA at DMM V displayed V at DMM0.20 0.21 177.0 7.63 7.630.19 0.20 167.2 7.24 7.230.18 0.19 157.2 6.81 6.800.17 0.18 147.8 6.39 6.390.16 0.17 137.5 5.96 5.950.15 0.16 127.8 5.54 5.530.14 0.15 118.4 5.11 5.120.13 0.14 108.7 4.69 4.690.12 0.13 98.7 4.26 4.270.11 0.12 88.8 3.83 3.830.10 0.11 78.7 3.40 3.400.09 0 69.2 2.98 2.980.08 0 59.1 2.55 2.550.07 0 49.1 2.11 2.120.06 0 39.2 1.70 1.690.05 0 29.3 1.25 1.260.04 0 20.0 0.87 0.870.03 0 10.2 0.44 0.44

author: Vgkid
author_rank: Super Contributor
timestamp: October 26, 2014, 03:10:08 pm
content: The build quality doesn't look to bad, nice of them to label test points on the underside. How warm does it get?

author: omgfire
author_rank: Regular Contributor
timestamp: October 26, 2014, 07:13:55 pm
content: Quote from: Vgkid on October 26, 2014, 03:10:08 pmIt boiled a cup of water, but did not get warm.

author: SharpEars
author_rank: Unknown
timestamp: October 27, 2014, 02:32:36 am
content: Quote from: omgfire on October 26, 2014, 07:13:55 pmTry measuring the temperature of that black bridge rectifier in your pic when you're outputting the full 10 amps at 30 volts. I bet it will be close to 100 degrees celsius.Update: Oh wait, it is looks to be attached to the case in the original pics, so it may be OK.

author: Rasz
author_rank: Super Contributor
timestamp: October 27, 2014, 05:33:49 am
content: no pfcotherwise its just a combination of ordinary ATX power supply with this:http://www.ebay.com/itm/DC-4-5-30V-0-50A-Dual-LED-Digital-Volt-meter-Ammeter-Voltage-AMP-Power-ES9P-T7-/111424457181its also STM8 based, add rotary encoder, rewind secondary trafo, change case and there we are, cleverlets hope it gets cloned so we might see them at $30

author: omgfire
author_rank: Regular Contributor
timestamp: October 27, 2014, 08:53:09 am
content: Quote from: to6ko91 on October 26, 2014, 02:41:35 pmIf you understand psu limitations, and limitations are adequate to your use case, then psu is acceptable.+ Case is nice. It looks good and it serves as a big heatsink for semiconductors bolted on it.+ Price is nice too.+ Fanless.+ Good efficiency.+ Can adjust voltage/current with output off. Some poor psu lacks even output on/off switch.+ LED display.+ Compact.+ Lightweight.+ No severe AC leakage.+ Capacitors look adequate (Samxon 105°C).- Ammeter on my unit is not working correctly below 0.3A. I asked manufacturer about that. At first they replied:"Your CPS-3010 is not dfective, it can not show the current below 0.11A because the current meter display error." In next email, they corrected themselves: "Sorry! i mislead you, i have checked some CPS-3010 in our warehouse, they all can show the current below 0.1A, your PSU can not show the current below 0.1A maybe the transpodrtation," They also provide calibration procedure.Anyway, ammeter has 4 digits with fixed period position: xx.xxA. So, first digit is effectively useless. Experienced technician can use 1mA resolution to diagnose complex devices like laptops. This is not possible with this psu. Lower model CPS-3205 (CPS-3205L) has 3 digits ammeter, but can switch to mA resolution. I thought that CPS-3010 will be superior to CPS-3205, but turns out, 3 digits ammeter on CPS-3205 works better than 4 digits ammeter on CPS-3010.- Some UI is on the back of psu (hard switch, output connectors), some UI is on the front. I don't find that ergonomic. Buttons are small and hard to press.- UI is very minimalistic: no memory slots, no PC connection, etc.- Manual does mention over voltage and over current protection: “When OCP is triggered, MCU shut down the output and ammeter highlights “OCP””. Some psu (like Korad) have button for OCP which determines psu behavior when current meets user defined limit: either switch from constant voltage to constant current mode (drop voltage), or switch off output. Gopher switch to constant current mode. I have no idea why manual mentions output shut down.- Psu is fanless, but not absolutely silent.- Regarding spikes on hard power on look here:https://www.eevblog.com/forum/buysellwanted/franky's-sales-thread/msg463182/#msg463182- LED display offers more contrast than LCD, but LED segments are not covered with tint film. Off leds are white and that decrease contrast in well lid environment. Could be fixed with tint film.- Supplied leads are a joke and should be thrown away. Banana plugs are screwed through insulation (who cares about wire stripping?). Crocodile connection is no better: wire is wrapped through hole but not soldered. Wire itself is thin and does not match 10A. Output wires inside psu are thick 12AWG, no problem here.- Capacitor on the output. This PSU is more constant voltage supply than constant current supply.- Rubber feet are hard, more like a plastic. PSU slides easily. I glued some rubber on it.- It't not possible to adjust voltage and monitor current at the same time. Power supply show set current while you adjust voltage.Overall, PSU suits my needs, but I would be more happy with lower model CPS-3205, (CPS-3205L, CPS-3205C).

author: SharpEars
author_rank: Unknown
timestamp: October 28, 2014, 12:35:18 am
content: Quote from: omgfire on October 27, 2014, 08:53:09 amWait,, the outputs are on the back? How idiotic is that? How much did this clunker cost? Ali express lists it at $103 - I think it's worth maybe $60 tops base on the quality from the pics...I mean the soldering is naaaastttyyy! Look at pic 17, did they spill a jar of rosin on the board or what? I'd be worried about longevity...Personally, I would have just gotten one of these for $80. At least it has outputs in the front and the insides are no worse:Link to 30V 10A power supply on ebay

author: omgfire
author_rank: Regular Contributor
timestamp: October 28, 2014, 02:25:39 pm
content: Quote from: SharpEars on October 28, 2014, 12:35:18 amHaving outputs on the back is not a bad thing. Many good psu have outputs on both sides. For instance, Gopher has option to auto enable output when power is on. So, it could be used as stationary DC supply for equipment. On the other hand, lack of outputs on the front is disadvantage, but since I attachedstackable leadsto psu, I cannot care less about location of psu outputs. I can attach crocodiles, hooks, probes, bananas,whateverto stackable leads.Quote from: SharpEars on October 28, 2014, 12:35:18 amYes, with international shipping it is a bit over hundred.Quote from: SharpEars on October 28, 2014, 12:35:18 amHow does no-clean flux affect longevity? For instance, how do you clean flux under BGA chips?

author: SharpEars
author_rank: Unknown
timestamp: October 29, 2014, 02:53:47 pm
content: Quote from: omgfire on October 28, 2014, 02:25:39 pmThe problem is the extra resistance of the longer (high gauge) wiring and the added (common mode) noise you pick up, both from the longer wiring and from having more connection points due to extension cables.Quote from: omgfire on October 28, 2014, 02:25:39 pmI would be more concerned about heat not being able to radiate properly from components that are covered on top (or all around) with flux. This may be a non-issue, though, for the particular components we are discussing.

author: omgfire
author_rank: Regular Contributor
timestamp: October 29, 2014, 08:14:47 pm
content: Quote from: SharpEars on October 29, 2014, 02:53:47 pmI use 13AWG (less than 10mOhm) leads. For example, supplied leads have more than 100mOhm. Extra resistance? Noise pick up on a cable connected to cheapishswitchingpower supply?

author: SharpEars
author_rank: Unknown
timestamp: October 29, 2014, 11:29:18 pm
content: Quote from: omgfire on October 29, 2014, 08:14:47 pmYeah, at 13 AWG for all leads, you're good in the resistance department.On the noise pickup issue, I guess it has enough ripple noise that common mode noise won't matter much. On the other hand I wouldn't call it all that cheapish if you paid over $100 for it when better supplies are available for $80 with outputs on the front, a far more useful place for them (and no measurement issues on the ammeter). Even on my $50 made in China 30v/5A version, the soldering job, although very far from perfect was much MUCH better than what was in your pictures. I'd never buy the supply you bought just based on the soldering I saw in the pictures alone (all other inconveniences aside).

author: bartwas78
author_rank: Newbie
timestamp: January 22, 2015, 04:40:42 pm
content: Hello, if someone is interested I received calibration method for my CPS-3205 model."Hi,please calibrate the power supply CPS-3205 as the following:1.Set the V/A selector switch to A position,2,Push the adjust knob then power on the power supply,the meter will display PUSH OFF,3 Press the ON/OFF button one time then press the LOCK button two times,the unit will go into voltage calibration(please note calibrate the voltage with no load), the volt meter displays 01.00 and amp meter displays 001, please adjust the adjust knob to set the output voltage to 1.005V,( you can push the adjust knob to select the range of ajusting) then press the ON/OFF button to calibrate the output voltage to 10.00V and 30.00V, after 30V voltage has been calibrated,please press the ON/OFF button to go into current calibration, connect your electronic load to the output terminal of the power supply, the unit must operate in C.C mode,the amp meter displays 1.00 and the volt meter displays 0001, please adjust the adjust knob to set the output constant current to 1.000A, then press the ON/OFF button to calibrate the output constant current 5.000A,after 5.0A has been calibrated then press the ON/OFF button to finish the calibration.Best RegardsJiang Min"I have used multimeter to calibrate it and it worked.by the way here is link to nice review of CPS-3205C

author: electr_peter
author_rank: Unknown
timestamp: January 22, 2015, 07:20:08 pm
content: Calibration procedure was very useful. Thanks, bartwas78.

author: janaf
author_rank: Frequent Contributor
timestamp: February 15, 2015, 02:57:33 pm
content: Thanks for the cal procedure. Mine has a slight zero offset.I've got two 5A-33V of this model and have no complaints. Good for the price, compact, seems well built.Actually, one small complaint: when setting voltage, the current display shifts from showing current to displaying over-current-set-point. It takes a few seconds before it goes back to showing actual current again. I'd prefer if I could monitor current while adjusting voltage. Same thing in current limiting mode; if you adjust current-limit-set-point, the voltage display shifts to showing voltage-limit-set-point instead of voltage for a few seconds.

author: mdijkens
author_rank: Regular Contributor
timestamp: March 04, 2017, 09:17:44 pm
content: I have this power supply also and am very happy with.For bigger currents I would really like to modify it with sense-wiring.If anyone has run iinto a schema or more info on this, I am very happy to learn more....

author: ted572
author_rank: Frequent Contributor
timestamp: April 25, 2017, 09:03:55 pm
content: Hello: I very much like the CPS-3201E, a 0 to 32 Volt, up to 5 Amp Power Supply. This unit has a 4 digit readout for both voltage and current. I posted the Calibration Procedure, Specifications for it, and general comments on easily improving the LED Display Contrast of any of the different GOPHERT Power Supplies.I highly recommend the CPS-3205E Power Supply as it has been very reliable for me. It is small, lightweight, and inexpensive at ~75 US$. If interested please go to ->https://www.eevblog.com/forum/other-blog-specific/new-2016-gopher-cps-3205c-review-teardown/msg1181084/#msg1181084

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 26, 2017, 12:25:03 am
content: Yuck, TL494.Try cooking it for a few minutes/hour at minimum output voltage and maximum load current.Try hitting it with transients (alternately open/short the output) at various settings.Try running at high or low line voltage.Try running at elevated ambient temperature.Thing's literally designed to explode, it's just a matter of finding the right permutation.Tim