Vantek DPS 3305P 32V/5A/160W Programmable DC Power Supply

[metalphreak]

Picked up one of these power supplies off ebay ( eBay auction: #270867656884 ) for about $190 Aussie Dollars. Has a USB connection for controlling it via a PC.

The software is a bit hacky but it seems pretty stable in operation. It's basically just a USB to UART bridge inside so I'm sure you can reverse engineer the serial protocol and write your own software. You can feed the software a csv file with voltage and current parameters in respect to time and have it automatically make changes (in a set number of loops too). It can also log voltages and currents as well. There is a 1Hz limitation to this software though. The minimum interval in the automatic mode is 1second regardless of the value in the csv file. The logger also only updates once per second. However, any changes to voltage/current/output are immediately sent to the power supply so you could in theory write your own program to switch faster than 1sec

Set voltage and current seems to be within spec. 5V reads as 4.995V on my meter (which is only 6000counts). There is an extra 0.005A offset on the current limiter even when set to 0.000A.

The fan is temp controlled and while not at all silent, it's hardly a screamer. I don't find it any louder than the good old rigol 1052E scope.

The whole thing is controlled by an Atmel ATMEGA8 chip. You can probably make out the resistor network it uses in there for something (made up of heaps of single SMD resistors).

When I was first testing mine using a 12V 50w halogen bulb, it cut out after a few minutes of operation. I thought it might be faulty or perhaps it was overheating? The fan wasn't coming on at all... So, I opened it up, and well, the fan had come unplugged during shipping Would have preferred that they use a more secure connector for that. In any case, I now know it does have an over temp shutoff.  One of the screws holding the top PCB had sheared off, but that was an easy fix. Other than the rough handling damage, everything else looks respectable.

The front panel buttons are hard plastic with clicky tactile switches behind them. From the photos I thought they might have been the nice soft squishy rubber type. Rotary encoder is smooth and isn't notchy at all. As you can see in the photos, the PCB was designed for a different encoder, so they've used a couple of jumper leads here. Solder joints and wiring looks clean though so no big deal. Makes it easier to replace if I have to in the future 

Best thing about this compared to a normal supply: Presets and Output switches! Has 5 memory presets which are saved to eeprom (survives power off). Just set voltage/current values, press shift button then the desired Mx preset button. Output switch is handy instead of having to turn the supply on and off each time. I should also note that when switching to a new preset, the output gets disabled. If you accidentally hit a preset button for 32V/5A you won't smoke whatever device you have plugged in

I've got a couple of videos showing how the front panel operates as well as the software, but they are 1080p and over 500mb each. Going to take a while to upload to youtube Will also take some noise and turn on/off readings with a scope when I get some spare time. 

Vids are a bit boring but a video tells a thousand words



Setting Memory Presets


PC Software


Vantec 3305P Specs
USB and cable Yes
Output Voltage 0-32V
Output Current 0-5A
Source Effect CV:0.05%+5mV; CC:0.1%+2mA
Load Regulation CV:0.05%+5mV;  CC:0.2%+5mA
Ripple and Noise CV:2.0mVrms; CC:3mArms
Protect Type: Over current, over voltage and over temperature protect.
Display Accuracy Voltage?±(0.5?+2digits);  Current: ±(0.5?+10digits)
Environment Temperature: 0 - +40?, RH?80?
Response time Up<50ms; down<5ms
Power supply 220V±10? AC50Hz/60Hz; 110V±10? AC50Hz/60Hz
Weight 6kg
Size 100x160x275(mm)
Accessories Manual x1, power cord x1?USB cable x1, CDx1

[armandas]

You can probably make out the resistor network it uses in there for something (made up of heaps of single SMD resistors).

It looks like they are using four shift registers and an R-2R network to make a 32-bit (or is it 2x16 in parallel?) DAC.

[saturation]

Looks like a supply with fine potential once the assembly flaws are fixed.  It appears as a linear supply with digital controls.  Just a tiny touch nosier than a pure linear supply, but that's the cost of the programmability.

For example

http://www.ebay.com/itm/MASTECH-LINEAR-DC-POWER-SUPPLY-0-15-VOLTS-0-3-AMPS-/200453517859?pt=LH_DefaultDomain_0&hash=item2eabf5f223

MASTECH HY1503C

    Output Voltage: 0- 15V @ 3A
    Output Current: 0-3 A
    Input Voltage: 110V/ 60Hz
    Constant voltage/ Constant Current
    Voltage and Current adjustment
    Power effect: CV<0.01%+1mV, CC<0.2% + 1mA
    Overload effect: CV<0.01% +3mV, CC<0.2% +3mA
    Waves and noises: CV<0.5mV r.m.s, CC 3mA, r.m.s
    Protection: High current limited.
    Ripple & Noise: <1mV rms
    Output Current: 0-3 A
    Operating Temperature: 0 - 102 F (0 -40 C), Relative Humidity: <90%
    LCD Accuracy is within + or - 2.5%
    Size: 9 x 6 3/4 x 3 3/4"
    Weight: 8 lbs
    6 month warranty

[Teknotronix]

How do you rate this supply after having it for a month or so? Still worth buying? Have you measured the noise on the output?

[Fender123]

Hi all,
I have one of these, from GoodLuckBuy, same 'DPS 3305P' marked Vantek but without the USB connector. I found some flaws with it - maybe it's just my unit, but I doubt it.

Basically, it is stable, low drift, accurate. But...

1. If you short circuit the terminals with less than 0.2 ohms, current is limited. But if you then turn off the output by pressing the o/p button, an unlimited current (>7A) flows without any indication. *** FAIL FAIL FAIL ***

2. Way too much AC leakage (electrostatic shield inneffective) - like 100Vac floating, 31uAac shorted, with 220Vac i/p. *** FAIL FAIL FAIL ***

3. There is a rather large electrolytic capacitor across the output terminals that spoils the current limit performance.

4. Not sure why it needs a 10A fuse, too large. For 220V, T2A is enough.

5. Usability-wise, the only thing I don't like is that when storing a setup, the output is turned off.

6. Construction-wise, the IEC inlet has an exposed live lug too close to heatsinks; not clear how this can pass Hi-Pot test. *** FAIL FAIL FAIL ***


Re: point #1, I would appreciate if any owners can verify.

[Teknotronix]

I have one of these in the post coming from preciseguage.com. I will do some tests when it arrives.

[nukie]

Thank you for documenting this sir!

Some say E cores transformer are better suited for a low noise power supply I don't know if this is true, but toroid sure looks a lot cooler! Toroids cost more to manufacture too.

[T4P]

Thank you for documenting this sir!

Some say E cores transformer are better suited for a low noise power supply I don't know if this is true, but toroid sure looks a lot cooler! Toroids cost more to manufacture too.

"Some say" But "All say" toroids are better .
Toroids have less leakage inductance and therefore , less EMI and easier going when it comes to filtering .
BUT ! ... They have a huge startup inrush current .
In fact , RS sells more toroids than they sell EI core Transformers .

[SeanB]

To solve the toroid inrush current you need to add a NTC inrush limiter, and replace the 10A fuse with a 5A or so slow blow fuse. That will drop the inrush current and keep it from causing massive dips on the mains on switch on.

[Teknotronix]

I received mine this week from preciseguage.com. Nice little unit for the price. Looking to order another one.

I will take the lid off it soon and post some pics to compare with MetalPhreak's. I will also try that inrush current issue.

[Teknotronix]

Here are some internal pics of my Vantek. It is the same 32V 5A model.

[Teknotronix]

For everyones's reference. I recently bought a second one of these supplies but was sent a Yori branded unit. These are technically the same but suffer from the same turn on voltage spike as the Quakko. Here are the results of my tests. Note that my Vantek unit does not suffer this issue.

IMO, no matter who you purchase from, make sure you specify Vantek as these seem like a better build overall.

[Fender123]

Has anyone checked about the unlimited short circuit current issue when turning output off, and AC leakage current I mentioned? (See my previous message)

[metalphreak]

Teknotronix: is the Yori the same inside? I highly suspect the firmware is the root cause of the Quakko/Yori issues. Perhaps the current limiting fail of Fender123's unit is due to some poor control programming. I don't have any Atmel tools to try and dump the code from mine, but if you do, you could try flashing the code from the Vantek unit onto the Yori? That's if it isn't code protected...

I'm in the middle of moving my "lab" around (again...) but I'll try to make some time on the weekend to test out Fender123's issues.

[george graves]

Has anyone found a good USA  source for these?

Or a reliable source for the Vantek brand without the turn on issues?

[george graves]

Seems to also be sold under the name Quakko - http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/programmable-dc-power-supply-32v-5a-lab-grade-hy3005dp/prod_49.html

[Teknotronix]

Teknotronix: is the Yori the same inside? I highly suspect the firmware is the root cause of the Quakko/Yori issues. Perhaps the current limiting fail of Fender123's unit is due to some poor control programming. I don't have any Atmel tools to try and dump the code from mine, but if you do, you could try flashing the code from the Vantek unit onto the Yori? That's if it isn't code protected...

I'm in the middle of moving my "lab" around (again...) but I'll try to make some time on the weekend to test out Fender123's issues.

The Yori appears to be identical inside. The sales person where I bought it from says they even come out of the same Caltek factory. Your idea about the firmware is interesting. I also don't have the Atmel tools, but if someone here can guide me in doing so I will happily take a look at my earliest convenience.

[metalphreak]

<-- you can see the Atmel chip here (I may have incorrectly guess it being an ATMEGA8 but its definitely an Atmel)

<-- that 6 pin header is almost definitely the in circuit programming connection

Someone with *any* experience with the atmel programming tools will probably be able to help you much more than me


http://www.atmel.com/Images/doc0943.pdf

VCC, MOSI, MISO, SCK, RESET, and GND would be the 6 connections. Something like an AVR ISP should be able to read it *if* they haven't got any code protection bits set.

[Teknotronix]

<-- you can see the Atmel chip here (I may have incorrectly guess it being an ATMEGA8 but its definitely an Atmel)

<-- that 6 pin header is almost definitely the in circuit programming connection

Someone with *any* experience with the atmel programming tools will probably be able to help you much more than me


http://www.atmel.com/Images/doc0943.pdf

VCC, MOSI, MISO, SCK, RESET, and GND would be the 6 connections. Something like an AVR ISP should be able to read it *if* they haven't got any code protection bits set.

Thanks mate. Might have to get myself an Atmel programmer/debugger. Too bad the old PIC Kit 3 I have does not work.

[george graves]

Seems to also be sold under the name Quakko - http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/programmable-dc-power-supply-32v-5a-lab-grade-hy3005dp/prod_49.html

Seems to have more mem keys?  And added some LED's.

[T4P]

It's this one right ? 
http://www.aliexpress.com/product-fm/428683956-MA009-30V-5A-mA-Display-Digital-Store-DC-Programmable-Power-Supply-DPS3305P-Programming-DC-Power-Supply-wholesalers.html
167$ for a programmable supply sounds good .
But i'm still buying a 30V/5Amps for 71$

[Teknotronix]

There must be a diff in the firmware of these as this Quakko has more memory locations with the same amount of buttons. This firmware difference must be the reason for the differences in the spikes as its the only thing that is different between them, as the internal appear to be exactly the same on mine.

[george graves]

Ah - there is a thread on these already. https://www.eevblog.com/forum/product-reviews-photos-and-discussion/0-32v-0-5a-with-usb-control-protek-p6035-quakko-hy3005dp/

This might be the "original" version (others being knock offs?)

http://www.protektest.com/Prodinfo.asp?prodid=P6035

[Bored@Work]

This might be the "original" version (others being knock offs?)

http://www.protektest.com/Prodinfo.asp?prodid=P6035

Protek has sold rebadged stuff in the past. That might be another one.

[george graves]

I emailed http://mastechpowersupply.com

I would like to ask you a question about 'Programmable DC Power Supply 32V 5A Lab Grade HY3005DP'.  Has this issue with the supply been addressed?  - it seems that it goes to a full voltage and current for 1 second at start up. Has this been fixed?  Or do the current units suffer this problem?  Thanks!  George

this issue still exist, and you need to turn the power supply on and
set it up before connecting the load.

Best regards,

Sean

I wonder what spec of a relay would be best for a 555 timer added to the output?