Yep. Me. Snatched it for less than that
I have some 'reverse engineering ' info.
The meanders on the pcb are there for a purpose. The two powerfets at the back have their own 0.1 ohm sense resistor to close the loop. These two resistors share a single trace on the board that is via-stitched between top and bottom layer and comes to the front of the board. The meanders on the front resistors inject the same trace length to the star point. The reason is load balancing. The pcb trace resistance would be different between front and back and the front fets woul pull more current than the back. Deliberate operation. Good design.
The bank of 6 mosfets on the main board is for range switching.
The use either 0.2 ohms for current measuring , in series with 0.02 ohms ( five 0.1 in parallel ). At high current they turn on the bank of six mosfets to short the 0.2 ohms out.
A relay toggles between the sense points. ( strange.. No analog mux ... Probably because there is a post divider protecting against large voltages.. )
My machine is off in the voltage measuring department. The programmed and measured currents are correct. The voltage measured on the terminals is wrong , so it probably needs adjustment.
The sticker said. Cannot adjust , but they didnt even try.... None of the pot seals are broken and this machine has no electronic calibration.... Lazy callabs...
Instead of one 3711A I bought two 3710A devices. They can be parallelled to handle more load or put in series for a higher voltage or used for two different projects at the same time.
The Maynuo specs quote almost an order of magnitude better basic accuracy (Maynuo 0.03%+0.05%FS Vs Array 4.00~35.99V?0.2%+30mV )
The Array generally resolves to three decimal places (1ma, 1mV) while the Maynuo stretches to four for voltage (0.1mV) and five for current (10uA!!), BUT that last current place is most iffy - call it four decimal places (100uA)
The array does boast a lower minimum or short circuit resistance; this is a function on the lower voltage mosfets. (The 500V Maynuo can "only" go down to about 0.25 Ohm)
The 500V Maynuo can only handle 15A, Vs the 360V Array's 30A. What do you really need?
The Maynuo battery test function is an eye-opener; especially if you use a lot of rechargeable cells, and they don't seem quite as efficacious as they once were. The battery test function quickly weeds out dieing cells, with poor mAhr figures
The Array comes with wingsWhy, I wonder? The Maynuo sports a front rubber bumper.
The Maynuo number pad is upside down (GRRR), but the Array number pad is even WORSE! Does this matter? Well, I find it slows down your direct input typing speed a lot, yes. To see how number pads SHOULD be laid out, look at an Array 3720 series (but don't look a the price - ouch)
The Maynuo sticks out about 120mm further (deeper) than the Array. How deep is your test bench?
The Array boasts FOUR fans to Maynuo's two. I suppose it depends on how big a fan fan you are. (Maynuo seems to manage fine with its internal pair)
The Maynuo includes a V-set function (Think: 300W Zener Diode!) while the Array appears not to offer this.
The Maynuo allows you to set a number of set points (i.e currents) and then switch or slew between them, so that you can observe how your power supply performs under transient load situations. I cannot see that the Array offers this. I am interested in transient performance, but your applications may not need this.QuoteLack of V-set? That's sad. Oh well.So I think that the Maynuo is " mostly winning" here, but it depends on your budget and whether you feel you actually need these extra features.The maynuo M9712 is only 60$ more but the M9712B is twice the price of the 3711
Good info thanks saturation, so the question still begs ... Maynuo M9712 OR Array 3711A
Both are around the same prices with the Maynuo being newer but the maynuo is only 150V and has battery test feature (Of course my prices are quoted from china directly)
Forget about the CA5030 from precisegauge, i can get a 3711A cheaper than the CA5030
Well the RS232 interface cable is quite literally cheap, compared to the prices fluke charges for a rs232 interface cableBut yeah, one area it seriously lacks is V-set.
3711 Adjusted and fully in-spec now. stupid callabs 'can't adjust' ... too lazy to open the box or download the cal manual... ah well their los, my gain.
You mean constant voltage?Yes
A whole new design with 250W for the base modelAt least they addressed the lack of CV and added a shitload of modes I guess it isn't designed by Xiao Tony right?
Hey guys,
I am new to this forum and am so happy I have found it. I have read every post you guys have written about electronic loads.
I am currently working with an Array 3711A and am not very happy with it. It works great for discharging but I am having serious problems with the remote control. I would like to do some basic control using MATLAB and the constant resistance function in this device but I have serious doubts about it's functionality for this purpose. I have noticed that when the device is programmed at lower resistances (<250 Ohm), it produces erroneous current measurements. Could this be to do with the input terminals? The device was previously used.
Can anyone recommend a load which may be better for electronic control? I am considering a BK Precision but am not sure yet.
Thanks,
Katalyst
Anyone know of any guides/manuals for the actual setup for using using a bipolar operational power supply (4 quadrant) as an electronic load. Specificaly how to accomplish CC CV CR CW modes of operation. I realize some of these modes may require additional circuitry to control the source/sink unit. I just got a new unused TDK/Lambda/Electronics measurements inc. BOSS20-10-1-D-PM Bipolar Operational Source/Sink Power Supply ±0 - 20V, 0 - 10A off Ebay.
I am not looking to be spoon fed, just get me pointed in the right direction.