Lab. power supply Twintex TPM-3003, worth the review ?

[Warhawk]

I have helped my friend with some design recently and he offered me to choose something from a local distributor (TME.cz) in return. I needed some PSU on budget and Twintex TPM-3003 was my choice. The first impression is better than I expected. Co-workers thought it's a TTI... Is there anyone interested in a small review (pictures, measurements etc.) ? It makes no sense to waste a time if there is no chance for you to buy this thing somewhere else in the world or nobody cares  .

link: http://www.twintex.com.tw/en-us/product/linear001.html
Price: ~ 3900CZK ~190 USD

[icpart]

I have helped my friend with some design recently and he offered me to choose something from a local distributor (TME.cz) in return. I needed some PSU on budget and Twintex TPM-3003 was my choice. The first impression is better than I expected. Co-workers thought it's a TTI... Is there anyone interested in a small review (pictures, measurements etc.) ? It makes no sense to waste a time if there is no chance for you to buy this thing somewhere else in the world or nobody cares  .

link: http://www.twintex.com.tw/en-us/product/linear001.html
Price: ~ 3900CZK ~190 USD

In a future I think to buy more powerful model TPS-3005. I think is better investment for money vs TPS-3003.

If you can post any review of that power supply I will be very happy to read it.

[malcom2000]

I'm looking around to by a better power supply (my current one is 35 years old). Your pictures of the interior of the Twintex TPM-3003, and a description of its workings are very welcome. More specifically, I'm interested in a supply that shows the voltage, both the actual and the set maximum current, and the power at the same time.

[Warhawk]

Guys I have no problem with that but I've been quite busy recently. Could you please write down some testcases I should do for you ?
Equipment is not a limitation.

[SharpEars]

I have helped my friend with some design recently and he offered me to choose something from a local distributor (TME.cz) in return. I needed some PSU on budget and Twintex TPM-3003 was my choice. The first impression is better than I expected. Co-workers thought it's a TTI... Is there anyone interested in a small review (pictures, measurements etc.) ? It makes no sense to waste a time if there is no chance for you to buy this thing somewhere else in the world or nobody cares  .

link: http://www.twintex.com.tw/en-us/product/linear001.html
Price: ~ 3900CZK ~190 USD

This isn't meant to sound condescending in any way, but these look like one step up from the "one hung low" supplies sold on eBay for $50 (i.e., less amps and more resolution display and programmability). I wouldn't count on these to deliver full rated power for more than 15 minutes. But hey, a teardown could prove me wrong .

[Rolo]

Would like to see if there is overshoot when switching the output. And the build quality. So yes, a teardown would be nice.

Verstuurd vanaf mijn GT-I9300 met Tapatalk

[LaurenceW]

Well, of course, there was a time when barely anyone had heard of Rigol, and that seemed to turn out OK. Will Twintex be the same? Hard to tell, and there's lots of PSU competition out there (barriers to market entry are much lower).  Manual is a bit Chinglish, but mostly there. Specs read OK, but there's a lot of buttons just for a single channel device!

As with all of these class of CPU-controlled power supplies, a huge amount of the instrument's performance and usability will be down to the software, which tends to be flakey and ill-supported on lesser-known Chinese products. I say "tends to be" because that is my general experience. No knowledge of this product, however. In other words - its a risk you must take.

It has a fan (no surprise for budget/mid-range power supplies), but NO mention of how noisy it migth be, or whether it is thermostatically controlled.

The high voltage (36V) OR the high current (6A) ranges are nice. Remote PC control is nice, too. If you need it, that is, otherwise you are just paying for stuff you don't need. Display resolution for both current and voltage is also good (assuming it is also accurate - no way to know without a full test). Many power supplies only go to a resolution of 0.1V and 10 mA - a bit course for finer measurements.

It ain't no TTI, tho, f'sure.

[Warhawk]

I will try to do some tests this weekend.
.. and yes, this is a big cheapo...

[joao2004]

Hi, i have one Twintex TPM-3005 and i will try to do an "review". For now some photos of the control board:





It is fan cooled. The fan turns On/Off automatically and has variable speed. There is also an safety thermostat of 85º on the heat-sink.

[pascal_sweden]

Would like to see if there is overshoot when switching the output. And the build quality. So yes, a teardown would be nice.

Verstuurd vanaf mijn GT-I9300 met Tapatalk

It would be good to check if there are voltage spikes. Not only when powering the unit, but also when the unit switches to another secondary on the transfo (when the relay switches).

[gvoima]

Hi, i have one Twintex TPM-3005 and i will try to do an "review". For now some photos of the control board:
...
It is fan cooled. The fan turns On/Off automatically and has variable speed. There is also an safety thermostat of 85º on the heat-sink.

Hi! First time here

I'm about to get this PSU and there's no info regarding (not on the manufacturers page or manual) about how this unit's output is isolated from the mains.
I'm no expert, but shouldn't that grounding wire (yellow) be connected straight to the chassis through a ferrite loop and not on the board like that?
Or is this just isolating some interference and there's another connection somewhere to the chassis?
Do you have any more pictures of the transformer?

[Warhawk]

Hi, I got a PM regarding the supply so I finally have some answers so put it here. I have TPM3003 thus everything below corresponds to this version.

Real size of the supply (to fit it into a cabinet):
Max. width = 130 mm (including small screws on the sides)
Max. height = 160 mm (including rubber feet and the top handle)
Max. depth = 320 mm (including front banana connectors, excluding power cord)

Turn-on, Turn-off behavior measurements
( numbers represent the picture index)

1) No load measurements
(Settings: LOW range, OVP=off, OVC=off, Ilim = 1 A)

Voltage	Turn-on	Turn-off
3,3 V	1	4
5 V	2	5
10 V	3	6

2) With 5R15 load
(Settings: LOW range, OVP=off, OVC=off, Ilim = 6,4 A)

Voltage	Turn-on	Turn-off
3,3 V	7	10
5 V	8	11
10 V	9	12

3) With 5R15 load, turn-on behavior, when a current limitation occurs in 70% of preset voltage
(Settings: LOW range, OVP=off, OVC=off, Ilim = varies)

Voltage	I-limit	Turn-on
3,3 V	0,4485A	13
5 V	0,6796A	14
10 V	1,3592A	15

4) Turn-on behavior for super sensitive circuits when a breakdown occurs (5R15 load)
(Settings: LOW range, OVP=off, OVC=off, Ilim = 15 mA, Vlim = 15 V)
- picture 16

5) Test with LED diode if it survives:
(Settings: HIGH range, OVP=off, OVC=off, Ilim = 15 mA, Vlim = 36 V)
- Test passed (repeated 10 times)
note: when the current is very small (1 mA), the turn-on time is very long (3 seconds !?)

Turn-on, Turn-off conclusion
In my opinion the supply behavior is correct. No overshooting or undershooting. It obviously have some smart trick because when the current limitation is on, the turn-on time varies a lot. It looks like the output capacitor was disconnected when the output is off. That would explain different turn-on times. What do you think ?

edit: I set 10 V and three different current limits 1 mA, 10 mA, 100 mA and the output rates are 11,4 V/s , 58,4 V/s , 365,7 V/s. Calculated capacities are not same however (87,71 uF , 171,23 uF , 273,44 uF)....

[Warhawk]

Build quality is not impressive at all. The biggest problem at the moment is the fan regulation. User joao2004 mentioned that his 3005 version has a variable speed regulation and temperature activated relay as a safety feature.  I must say that my fan has only on/off states controlled by the relay.
There is also some kind of a temperature sensor (measured resistance 0,3ohm in both directions) but it is obviously faulty or does not work by design.

Update: OK, so in fact the supply has only ON/OFF regulation by design. That regulation uses the big round relay close to the heatsink. That second white thing is for a temperature protection. I removed the connector on picture P7060207 and put there 10k multi turn trimmer. At some certain point the supply turns off the output (OTP - over thermal protection). So the system measures temperature but does not regulate the fan.
 

[Warhawk]

pictures 2

[Warhawk]

pictures 3

[gvoima]

Very nice pictures and measurements!

Seems like for the price, this is a good power supply. The TPM-3005 is only 149 € (and 138 € for two) at tme.eu. So nice!
Based on these measurements, I think I'll order the TPM-3005 model. So I can reply back when I get it if the fan regulation is the same on/off that's in the 3003 version.

And if someone is getting one of these, notice that there's four models; 3003 and 3005 and both have an E-version (3003E & 3005E). Those do not have the dual stage design (e.g. 15V at 6A and 36V at 3A), only one mode e.g. 36V 3A.

[Warhawk]

Very nice pictures and measurements!

Seems like for the price, this is a good power supply. The TPM-3005 is only 149 € (and 138 € for two) at tme.eu. So nice!
Based on these measurements, I think I'll order the TPM-3005 model. So I can reply back when I get it if the fan regulation is the same on/off that's in the 3003 version.

And if someone is getting one of these, notice that there's four models; 3003 and 3005 and both have an E-version (3003E & 3005E). Those do not have the dual stage design (e.g. 15V at 6A and 36V at 3A), only one mode e.g. 36V 3A.

Please hold-on for a day or two. I want to measure a real transient response when the output is ON. However, I need to prepare a test jig to measure the speed of CV->CC transition.

The fan control will be the second thing I want to do. The fan is in series with the temp-relay so adding the small fan regulator will be easy.

[Warhawk]

Yesterday I checked the step response of the supply. I took STP16NF06  in series with 0,1 Ohm resistor. The supply was set to 5V, 1A.
See images below.

Note:
I know that it is far away from ideal setup but it was a late evening.
A gate driver is missing, the gate is driven only by AWG DG1022U with 50 ohm output, +8/0V output signal.

[Warhawk]

I declared a war to procrastination and made a simple fan controller. I have already had good experience with : http://www.belza.cz/pcfan/farg.htm (Alan's) so I just built it in.
I used 5k NTC, 10k multi-turn trimmer and STP16NF06 MOSFET. It is also necessary to swap pins on the connectors. The regulator takes the same place as previous relay did.

Note: The transistor has to be isolated from the heat sink ! I could not find any isolation spacers at home at the moment so pictures are arranged only. Nevertheless the circuit works very well.

 
 

[gvoima]

Very nice! Did you consider to swap the fan altogether? You seem to have a rigol scope, so compared to that fan, how loud is the psu with this fan mod (just a guess, no measurements required ofcourse)?
And cheers for the step response measurments

[Warhawk]

Very nice! Did you consider to swap the fan altogether? You seem to have a rigol scope, so compared to that fan, how loud is the psu with this fan mod (just a guess, no measurements required ofcourse)?
And cheers for the step response measurments

Yes, I considered it but it turned out to be not necessary. My only changes are a better thermal paste under all transistors and the simple fan regulator described before. Then I made a few measurements with the fan control. I took the PS, shorted the output terminals and set a constant current operation. That is the worst case for the regulation transistors. Heatsink temperature was logged with BM257s . The top housing was placed back to simulate a real operation.

Result is that a cooling effect is not proportional with the fan speed at all. Look at those two charts in the attachment.

Setting 1 - over about 46°C the fan ran at the top speed (N-MOS fully conducted)
Setting 2 - even on 57°C the fan was still regulated to acceptable sound level (50% of the original ?)
Ambient = 29 °C (It was very hot that day).

A temperature difference was only 5° but the noise level was significantly reduced.
 
With "setting2", the nose level at 49°C +/- corresponds to DS1074z.

[icpart]

Hi guys.
These days I decide to order Twintex TPM-3005 from TME. My first impressions were good for this supply about functions and display measurement resolution.
It have full support for SPCI command via serial interface but I had no the opportunity to test it with PC. The included PC software is crap and it is based  on Labview program. In CD are included some examples for Labview.

But  UNFORTUNATELY now my brand new power supply is dead  .  Today I really have bad luck.
It is worked only few hours. That night I decide to test it  with some resistor load with about of 40-50W output power. The most funny is that the power supply died when it was without any load at output terminals.
It was only power on my table and at one point it turns itself off. When i tried to turn in again there was no reaction. After that i checked the fuse of input power terminal and it was blown.  And now it is total dead.  Very very strange FAIL for that power supply.  And now i must to return it to back to TME.
Warhawk is maybe right about quality of that power supply Twintex. But the good programmable supplies with  full support for SPCI command set cost x3-5 in price which are above my budget.

[Warhawk]

icpart - I am sorry to hear that. As far as I remember there is no "warranty void if removed" sticker so It might by a good idea to remove the housing and check what is wrong there. When I played with my supply I found out that some connectors are loose by nature (crap Chinese copy of JST or something like that). Maybe you can check it out and possibly save some money for the return to TME.


Twintex should rather deliver their equipment like a DIY kit.... I would actually appreciate it for nearly all alike electronics..

[icpart]

Thanks Warhawk. I returned lab power supply to TME.
TME are total idiots  . They do not want to admit my warranty because according to them I switched the input voltage to 110V and transformer is burnt after that.
I am almost 100% sure that switch was at 220V and no 110V. Also I worked with power supply some time without any sign of overload in primary winding like smell or something else.
What do you think guys if it is possible the transformer to withstand several hours without to burn if the primary winding is set to 110V in 220V power line?

[icpart]

My repaired Twintex TPM-3005 power supply is dead again       
Same problem as before. The primary winding of transformer is burnt again. Today i tested one boost module from ebay with maximum input current of 3A, but with that load the PSU worked normally, after that I decided to test another sepic module with only 0.2A input current and in that moment I heard only how the input fuse of power socket is blown and my power supply turn off after that. The same problem as before.
This time  I open it to see what going on after last service repair. On first look the transformer has been rewound. I measured resistance on primary winding and seems it is broken.
Can someone to give me a suggestion of what may be due to this winding to burn out for the second time? Maybe incorrectly calculated diameter of primary winding wire?

[Warhawk]

My repaired Twintex TPM-3005 power supply is dead again       
Same problem as before. The primary winding of transformer is burnt again. Today i tested one boost module from ebay with maximum input current of 3A, but with that load the PSU worked normally, after that I decided to test another sepic module with only 0.2A input current and in that moment I heard only how the input fuse of power socket is blown and my power supply turn off after that. The same problem as before.
This time  I open it to see what going on after last service repair. On first look the transformer has been rewound. I measured resistance on primary winding and seems it is broken.
Can someone to give me a suggestion of what may be due to this winding to burn out for the second time? Maybe incorrectly calculated diameter of primary winding wire?

Could not be there a problem with the transformer mounting bracket ? Is it isolated ? If not, it acts as a shorted one turn. Please check, I can also help you negotiating with TME.
Good luck !

[Zenner]

Maybe the transformer has too high inrush current? NTC resistor might be a good solution? For example for 220V, 10 ohm cold state resistance will limit current to 22A... hmm... maybe more resistance is needed, like 100 ohms?

[Zenner]

Measured the inrush current with current transformer, and got about 35 A pulses, lasting about 5 ms. So maybe it is worth suppressing, to protect the transformer primary winding.

[vvmm]

Did anyone else have problem with the Twintex TPM-3005 PSU?
I want to buy one from TME, but based on the above experience I'd rather ask first. Is it a one-time case or they are badly designed?
The PSU is exactly what I need.
I previously had a QJE supply that went bad and got replaced with another one which also went bad. I don't want to have the same experience with this one.

[snik]

I got an new TPM-3005 and my PSU has an Error too.
When i switch the PSU on and open the Output, Power comes on, but after a moment it switches the output-power off and after another moment  the output-power comes back an at this time the PSU regulated the Voltage and Current normaly.
This error occurs every time when i switch on the PSU only once after start up, but this is not a normal behaviour...
Also the current reading isn't very good and some mA away.
Here is a Video of the switch-on error :

[vvmm]

Oh my... Have you contacted TME?
I really want a good PSU. Is there any good one at this price range?

[Mr. Scram]

This look like an interesting unit, but obviously quality needs to be under control.

[snik]

Oh my... Have you contacted TME?

Got replay today after very long waiting from TME an they tell me, that this behaviour is not  a failure ... They say this is the self-checking procedure 

Never see an PSU which shortly cuts of the Output Voltage ... 

Is there an owner of this PSU who can confirm that this is at every Unit after first switch on ?

[Warhawk]

I'll check for you in the evening or tomorrow.

[vvmm]

I'll check for you in the evening or tomorrow.

Wow, I'm really curios if that's the same behaviour.

Meanwhile, I bought a TENMA 72-2540, a KORAD 3005 clone and I'm very happy. The inside build quality is fantastic compared to the original KORAD and I do hope it will last long. I think it's much more reliable than this Twintex.

[joao2004]

Hi, i have the same PSU and mine has a similar behavior... sometimes when i switch the output on, it will switch the output off and display "ADC RST" and after a few seconds switch it on again...

[Warhawk]

My PS does not seem to have such problem:

[snik]

Hi, i have the same PSU and mine has a similar behavior... sometimes when i switch the output on, it will switch the output off and display "ADC RST" and after a few seconds switch it on again...

Here is the answer from the technical guy :
"When we turn on the programmable power supply, it start a self-checking procedure. If there is any unusual results, it will display ADC RST. Same as the video showed. Then the procedure restarts, till it functions well. Only after that, the CV lights up, then output the preset volt."

That is really strange. And my PSU brings up Voltage on output first and after that the unit will check if Output Voltage is okay and shut it down cause somethings wrong ? What is when Output-Voltage is really wrong, then it will burn up my circuits ? This can't be okay. 
And the PSU from Warhawk seems good and has not that behaviour...

I've send Warhawks Video to them, now i will wait for a new reply.

[Warhawk]

I cross my fingers for you. Are you talking to German, Czech or Polish guys from TME?

[snik]

I cross my fingers for you. Are you talking to German, Czech or Polish guys from TME?

German support sends me replys from polish team.

Meanwhile they tell me again this is not a failure, when output switch on-off-on ...    I have two Korads, one DP832 and two noname chinese PSU and none of them do this. 

[nctnico]

Just return it ASAP. They are trying to stall so the no-hassle return period is over.

[Warhawk]

I asked you because I could help you with calling the Czech folks.
Tell them that if they're not taking the unit back, you ship it to Dave for a teardown +rant and they're not going to sell any unit more.
(I know it is naive but I wish this was true).
 

[snik]

After almost  14 days of no response , TME told me now that technicans say that my PSU is not faulty and this behaviour is normal and they send it back to me...   

Now i will used my cheap korad psu further , and don't replace it with the twintex, because i'm little bit worried about my circuits... 

So then, with my experience with this PSU, i can't recommend it. 

Just return it ASAP. They are trying to stall so the no-hassle return period is over.

Sadly the 14 day time was over when i recocnized the error, because i was busy when it arrived and i has tested it not completly  ... 

[Zenner]

There is a problem with current measurement: i just noticed that with 32 volts and no output current the measured current is about 3 mA and power about 100 mW.