Small new ATTEN PPS3005S programmable power suplly

[Smoking]

Hi electronic fans,

ATTEN has a new little programmable power supply : the PPS3005S

Only €109,- (€130,- including tax)There is now stock in Europe!
http://www.atten.eu/power-supply/atten-pps3005s-programmable-power-supply.html

The unit has a range from 0~30V and 0~5Amp and can store preset values

[slburris]

RS232 interface, optional
USB interface, optional

Bah!  Where's: ethernet interface, optional?

Anyone have one of these to post some teardown
pictures?  I have a Circuit Specialists rebranded Atten supply
and I've been quite happy with it. 

Scott

[Bored@Work]

Not having any PC interface would explain why they are selling it relatively cheap. It is missing an important feature of a programmable power supply.  Just having some memory for storing settings via the front panel is hardly a big difference compared to classic analog bench power supplies.

[Smoking]

Not having any PC interface would explain why they are selling it relatively cheap. It is missing an important feature of a programmable power supply.  Just having some memory for storing settings via the front panel is hardly a big difference compared to classic analog bench power supplies.

Well I do not totally agree with you.
If you want the pc control you mostly also want a multi output version.
And those are also very affordable. Check the website.

But would it not be more fun to make your own interface with for example a Arduino!

Maybe if you ask me nicely Iwill do a little teardown 

[sacherjj]

The dual variable plus 5V supply is only a few bucks more.  I think there was a thread on that one here a while back.

[Bored@Work]

Maybe if you ask me nicely Iwill do a little teardown 

No, I won't ask. Not nicely or otherwise. You want to sell this stuff. It is your job to convince us it is good stuff, not our job to beg you for information.

[Smoking]

Well after the nice and and friendly requests   here some inside pictures from inside.

You can clearly see the left out space for the USB and Serial connection on the back of the unit.
On the other picture there are 2 connectors, a black header and a white one.
So I am sure that there are a lot of people who can "hack" / "connect" the unit to work with there own interface.
(if you use a Arduino ethernet control is possible to! )
If you do not want that no problem just ask for the one with the serial or USB interface installed.

[bobski]

One of these arrived at my doorstep this afternoon... It seems to have a few issues that need re-engineering.
- The buttons are slow. If you just quick punch a button, you'll get no response no matter how hard you press. You have to slowly and very deliberately press the button to get the desired action. It really gets annoying when you're trying to move the selected digit over.
- The switch to constant-current is slow, or maybe there's too much filter capacitance on the output. If you set the supply to 10V, 10mA and (expecting the current limiter to do it's job) touch the output to an LED, you'll end up with a quick flash and one less LED in your parts collection.
- The fan is constant speed, always on, and it's distractingly loud.
- The zip ties keep things tidy, but for some reason I feel like the AC lines straight off the transformer shouldn't be bundled with the wiring for the DC regulators.

On the up side, the unit is controlled by an ATMEGA88PU running at 8 MHz and 5V. There's a nearby 6-pin header which may or may not be ISP (I'll have to trace the pins)... This is all visible in the pic. I tried swapping in a 16MHz crystal to see if that would help with the control responsiveness, but got no noticeable change in behavior what so ever. I wonder if someone forgot to set the fuse bits and the controller is running on its 1MHz internal clock.
The displays appear to be driven by a bunch of 74HC595D shift registers and a mess of SMD current limiting resistors. Low tech, but effective.
Since the 'mega88 doesn't have on-board USB support, I expect the 4-pin connector consists of the TX and RX lines along with 5V and ground. That's all that would be needed to interface with a USB UART bridge.

[edit]
Yeah, it's ISP. From left to right (left most pin is numbered 1, so 1-6): Ground, VCC, MOSI, MISO, reset, SCK.
Let the hacking begin.
[/edit]

[Smoking]

Hi Bobski,

Congrats with your PPS3005S unit!
The buttons are a bit slow indeed but not that slow that you have to wait. Normal pressing will do just fine.
( I just tested it and I did not notice it the first time because the first time you are allways a bit slower because you do not know how everyting works)
I miss a little conformation beeb ( but that is personal)
I did the same test with the led but my led is still working fine    (maybe bad quality led please update me about that)
Than the fan noise . Yes the units work with a active fan and yes it makes noise. This is easy to expleane see the pictures , the unit is using a simple aluminium plate to cool. this is not the most efficient way. But it saves weight! replace it with a big heavy cooling block and you solve the noise problem but this makes the unit so heavy that it is not economical to ship etc.

About the 1MHz internal clock I will check this with ATTEN.

Update : I will put a FREE RS232 interface in all the PPS3005S units so they will be included
ATTEN.EU only

[hisense999]

I just got my unit from Taobao and I can say I'm disapointed.

- No cables (banan plugs etc.) I like to have a lot of cables with my old cheapest one I got many including even 9V battery connector so I must use cables from old unit.

- Very noisy I can say is even too noisy.

- This buttons are horrible I preffer knobs, with my old power supply take one second to change parameters here to change simple parameter take too long time.

Anyway instead of bad things I like this unit is noisy and quiet big but looks very professional and have accurate settings.

So as total - way for Atten is give up this USB etc. options and the best is to put two knobs for V\A make it not so noisy and if this can show currency consumption with resolution of 0.001mA then I will throw away my old power supply and put Atten on a king place in my room, but just now I preffer old power supply which I bought 2 years ago for ~40USD and Atten I want to keep only as unit which can be usefull sometimes as for hobbysts this don't give any special value if they have already power supply which make them happy, but if they don't have any then maybe PPS3005S is a good option.

B.R.

[Smoking]

Hi Hisense,

There is always a power cable included ! If there is not, well you bought it from taobao, so I can not even guarantee it is new or genuine ATTEN made. No one told you there where banana clips included they never are so how can that be disappointing? (did you ask the seller?)

The noise is the same as a old computer power fan and in fact it is the same type fan.
Noisy yes, too noisy? no .( my computer makes a hole lot more noise! )

The buttons work fine (but I can understand that they can be anoying if you are a quick person).  But if you prefer turn knobs why buy one with buttons??
And big?? This unit is small 13cm W 16cm H 25cm D

I want to make clear this is a very low budget programmable power supply when you need memory functions and interfacing.
If you want high end, do not do not buy this unit.  And really you are comparing a $40 unit with this ATTEN? Please show me a 30V 5Amp programmable power supply that is new for $40,- 

[scrat]

On the up side, the unit is controlled by an ATMEGA88PU running at 8 MHz and 5V. There's a nearby 6-pin header which may or may not be ISP (I'll have to trace the pins)... This is all visible in the pic. I tried swapping in a 16MHz crystal to see if that would help with the control responsiveness, but got no noticeable change in behavior what so ever. I wonder if someone forgot to set the fuse bits and the controller is running on its 1MHz internal clock.
The displays appear to be driven by a bunch of 74HC595D shift registers and a mess of SMD current limiting resistors. Low tech, but effective.

IIRC, someone had the same thought about the clock, and posted in this forum the results. The guess was right. Can't remember if it was the same model, but the issue was the same, so it's highly probable...

[hisense999]

Hi Hisense,

There is always a power cable included ! If there is not, well you bought it from taobao, so I can not even guarantee it is new or genuine ATTEN made. No one told you there where banana clips included they never are so how can that be disappointing? (did you ask the seller?)

The noise is the same as a old computer power fan and in fact it is the same type fan.
Noisy yes, too noisy? no .( my computer makes a hole lot more noise! )

The buttons work fine (but I can understand that they can be anoying if you are a quick person).  But if you prefer turn knobs why buy one with buttons??
And big?? This unit is small 13cm W 16cm H 25cm D

I want to make clear this is a very low budget programmable power supply when you need memory functions and interfacing.
If you want high end, do not do not buy this unit.  And really you are comparing a $40 unit with this ATTEN? Please show me a 30V 5Amp programmable power supply that is new for $40,-

But instead what I wrote I'm happy with my unit as I mentioned before, just I pointed out what can be done in different way to make cheap bomb as RIGOL done with cheap osciloscope. And I'm so happy with my ATTEN PPS3005S cuz in China I bought it for Chinese price so is perfect value for money. Power cable of course I got.

B.R.

[Smoking]

Thank you for all your comments.
I have send the info about the 1MHz suspected problem to ATTEN and will give a update.

What I really hope is some one who makes his on interface on this unit. 
I will try to get the commands so every one can make his own interface.

[bobski]

IIRC, someone had the same thought about the clock, and posted in this forum the results.

In this thread? https://www.eevblog.com/forum/index.php?topic=3909.0
^_^

[scrat]

IIRC, someone had the same thought about the clock, and posted in this forum the results.

In this thread? https://www.eevblog.com/forum/index.php?topic=3909.0
^_^

Yes! How did you know about it?

[IanB]

The switch to constant-current is slow, or maybe there's too much filter capacitance on the output. If you set the supply to 10V, 10mA and (expecting the current limiter to do it's job) touch the output to an LED, you'll end up with a quick flash and one less LED in your parts collection.

I think I'd put this down to operator error.

One should set the current limit to 10 mA, set the voltage to minimum, momentarily short the output and then attach the LED. After attaching the LED, ramp up the voltage until the current reaches 10 mA and stabilizes. Then the LED will not be dead.

[bobski]

One should set the current limit to 10 mA, set the voltage to minimum, momentarily short the output and then attach the LED. After attaching the LED, ramp up the voltage until the current reaches 10 mA and stabilizes. Then the LED will not be dead.

So expecting the supply's current limiter to actually limit current is operator error? What you're suggesting is tip-toeing around a limitation or shortcoming in the design of the supply. If the circuit is breifly opened (say by a hand-held connection), your process would have to be repeated.
Yes, the test conditions I chose were a fair bit beyond what I would normally use for LED testing, but IMO the supply's poor response was far more extreme.

[IanB]

Yes, the test conditions I chose were a fair bit beyond what I would normally use for LED testing, but IMO the supply's poor response was far more extreme.

You want a 5 A supply to regulate with no overshoot at 10 mA, or 0.2% of full scale? I figure you are asking a bit much of a low cost power supply.

It is in the nature of control systems that you can have a fast response at the cost of some overshoot, or you can have a damped response with no overshoot at the cost of slow response time. I feel that if the control system could regulate accurately at 0.2% of full output, it would necessarily react very slowly at 50% of full output. I don't know of a practical way around this, unless perhaps by using a logarithmic scale on the current regulation?