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
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
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
![Sad :(](https://www.eevblog.com/forum/Smileys/default/sad.gif)
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
![Tongue :P](https://www.eevblog.com/forum/Smileys/default/tongue.gif)
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
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
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
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
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
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
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
![](http://i.imgur.com/eCBWEs.jpg)
![](http://i.imgur.com/Bvo7gs.jpg)
![](http://i.imgur.com/7to2Fs.jpg)
![](http://i.imgur.com/jgmRIs.jpg)