Author Topic: New toy: Itech IT8512+ Electronic Load (Read 32727 times)

Thomas · « **on:** March 11, 2015, 09:33:46 pm »

Hi there!
Just got this from Ebay, $460 including USB cable and shipping to Norway.
It's a 120V 30A 300W electronic load similar to Maynuo and BK Precision and others.

Pretty happy with the thing so far, but I haven't tested all the features yet.
The supplied software is useless

It's got a nice two-line VFD display

What does the 10 in a circle mean? Can it be recycled 10 times?

This model has SOIC opamps near the center of the board. Some of the other models have DIL chips there.

The white thing is a bracket for a TO-92 device (temperature sensor I guess). The TIP42C drives the fans (again, I guess).

xrunner · « **Reply #1 on:** March 11, 2015, 09:35:52 pm »

Good score!

krivx · « **Reply #2 on:** March 11, 2015, 09:44:16 pm »

0.02% voltage accuracy? Seems very good for the price.

Thomas · « **Reply #3 on:** March 11, 2015, 09:50:13 pm »

Yes it seems to agree within 3mV and 0.5mA of my Agilent 34405A multimeter. Nice.

miguelvp · « **Reply #4 on:** March 12, 2015, 08:46:48 am »

I like high res pictures as much as the next person, but you should at least have the preview ones no bigger than 1024 pixels wide so we don't have to wait forever for the page to load.
Maybe they are hosted by a slow server but it make my system lag so I bet the images are pretty big!

Thomas · « **Reply #5 on:** March 12, 2015, 08:54:39 am »

Sorry about the big pictures.
I have now edited to 1024x683 pixels for the previews, did that help?

Ericho · « **Reply #6 on:** March 12, 2015, 10:00:18 am »

I have the Maynuo version of it.

I got it of ebay 6 months ago, could use it for a single project I was having fun with back then.

Turns out I use it a lot, really a usefull tool, didn't expect that. Should have purchached one years ago.

jlmoon · « **Reply #7 on:** March 12, 2015, 05:24:12 pm »

That design is strikingly similar to my B&K 8500 too.

HKJ · « **Reply #8 on:** March 12, 2015, 05:39:19 pm »

Quote from: jlmoon on March 12, 2015, 05:24:12 pm

That design is strikingly similar to my B&K 8500 too.

Even the communication protocol is similar.

jlmoon · « **Reply #9 on:** March 12, 2015, 05:57:26 pm »

Quote from: miguelvp on March 12, 2015, 08:46:48 am

I like high res pictures as much as the next person, but you should at least have the preview ones no bigger than 1024 pixels wide so we don't have to wait forever for the page to load.
Maybe they are hosted by a slow server but it make my system lag so I bet the images are pretty big!

More power captain.. More power!!!

HighVoltage · « **Reply #10 on:** March 12, 2015, 06:05:19 pm »

Actually the design is a complete copy of the new BK Precision Model 8600
The new BKP 8600 has also the lights behind the control buttons and switched to circular numeric buttons.

The big question is, who is copying from whom?

http://www.bkprecision.com/products/dc-electronic-loads/8600-150-w-programmable-dc-electronic-load.html

Thomas · « **Reply #11 on:** March 12, 2015, 06:57:25 pm »

Yes, they do look very similar.
The price, however, is not similar: $1295 for the 250W version.

I'd like to have a pair of those rubber frames on the front and rear

macboy · « **Reply #12 on:** March 12, 2015, 07:09:03 pm »

There is no copying going on here, one is sourcing from the other, or both are sourcing from a third party. B+K definitely does this. My B+K multimeter is sourced from Metrix.

LaurenceW · « **Reply #13 on:** March 12, 2015, 10:24:31 pm »

I think I agree with Macboy. I have a Maynuo, and the designs are really too similar to be copies; more likely they are variants from the same original third party designer/manufacturer. That manufacturer has gone to the "trouble" to produce slightly different display options, to suit different major customers. Personally, I do prefer the newer B+K (and, as already used by the Maynuo brand) fine dot matrix display, over this slightly in-yer-face 7 segment one. Meh, my preference.

Yes, I have found my meter serves as much more than a dummy load. Precision volt meter, higher current meter than any of my other meters, battery discharge and capacity tester, variable power resistor, constant current source for driving large LEDs (when fed by a power supply), and transient load tester for power supplies. And even a 300W lab heater, on cold days!

Software works, but definitely written by a 12-year old colour-blind kid, who clearly skipped the class on man-machine interface design, and went straight to coding... it goes as far as to mimic 7 segment displasy, ferchrisake!!

And price, of course, is no real indicator of what lies inside. Price is what the owner of the brand thinks they can sell the instrument for, and nothing else. B+K have one idea of that, Maynuo and others have a different one.

chickenHeadKnob · « **Reply #14 on:** March 13, 2015, 12:58:05 am »

This topic of who copies what in the precision load bidness seems to come up regularly.

Dave's response in another thread:https://www.eevblog.com/forum/testgear/why-is-bk-precision-still-in-business-bk8500-programmable-load-oem-found/msg138916/#msg138916

edit: oops, screwed up link

HighVoltage · « **Reply #15 on:** March 13, 2015, 01:42:51 pm »

The funny thing is, that I saw the BK Precision 8600 instrument at the electronica 2014 in Munich and was surprised to see a new design, since I just had bought the 8500 a few weeks before. When I asked one of the guys that seemed to know about the unit and its new design, he claimed that BK Precision had re-designed the 8600 so it would be different from all the other DC loads that looked exactly like the 8500.

Well, it seems now, that there really is a designer at work, that makes the unit for more than one company available.

Thomas · « **Reply #16 on:** March 13, 2015, 08:15:48 pm »

Hmm, mine seems to have a reverse diode across the input.
I sometimes use it for discharging batteries, that means I better be confident about the polarity before connecting. This is usually no problem, but the batteries for my drill, for example, have no indication on polarity. Would be interesting if I get it wrong one time.

I wonder how much that diode will take?
Some investigation is in order.

Mike Warren · « **Reply #17 on:** March 13, 2015, 09:34:19 pm »

Quote from: Thomas on March 13, 2015, 08:15:48 pm

Hmm, mine seems to have a reverse diode across the input.
I sometimes use it for discharging batteries, that means I better be confident about the polarity before connecting. This is usually no problem, but the batteries for my drill, for example, have no indication on polarity. Would be interesting if I get it wrong one time.

I wonder how much that diode will take?
Some investigation is in order.

The diode you read is most likely the body diodes in the MOSFETs. You definitely do not want to connect a battery to it the wrong way round.

I've had the cheap REK version of these loads for a couple of years. It's still going great and I find I use it way more than I expected when I bought it.

https://www.eevblog.com/forum/testgear/why-is-bk-precision-still-in-business-bk8500-programmable-load-oem-found/msg220287/#msg220287

Thomas · « **Reply #18 on:** March 13, 2015, 09:59:25 pm »

Yes, of course, the body diodes will be visible even if the output is switched off. They don't care about gate voltage. Bah, how could I miss that

8x IRFP250N, each with a body diode rated at 30A makes it pretty robust. On the other hand, this will probably kill one or more of the MOSFETs if stressed.

Not a huge concern, just something to be aware of.

mcinque · « **Reply #19 on:** March 14, 2015, 08:34:20 am »

About "who's copying who": the story is that the Engineer that designed the instrument for Itech (now owned by B&K) left the company taking with him all the designs and founded Maynuo.
So the Itech and B&K are replicating the BASIC original design (in fact the Maynuo was for many years the only model with 4 data fields on the screen).
Itech and B&K are the same models with different prices and markings, while the Maynuo seems to be the original design with some improvements.
Anyway, the B&K model is still overpriced compared to Maynuo.

HighVoltage · « **Reply #20 on:** March 14, 2015, 09:02:17 am »

Quote from: mcinque on March 14, 2015, 08:34:20 am

About "who's copying who": the story is that the Engineer that designed the instrument for Itech (now owned by B&K) left the company taking with him all the designs and founded Maynuo.
So the Itech and B&K are replicating the BASIC original design (in fact the Maynuo was for many years the only model with 4 data fields on the screen).
Itech and B&K are the same models with different prices and markings, while the Maynuo seems to be the original design with some improvements.
Anyway, the B&K model is still overpriced compared to Maynuo.

That explains a lot.
Thanks!

mcinque · « **Reply #21 on:** March 14, 2015, 02:21:13 pm »

I must add that the Itech software is quite crappy while the Maynuo is nice and usable. Don't know the BK but I guess it should be the same thing of Itech.

HighVoltage · « **Reply #22 on:** March 14, 2015, 04:10:00 pm »

Quote from: mcinque on March 14, 2015, 02:21:13 pm

I must add that the Itech software is quite crappy while the Maynuo is nice and usable. Don't know the BK but I guess it should be the same thing of Itech.

I have a Maynuo M9812 and a BK Precision 8500 and find myself using the Maynuo more, because of the better software and the extra information on the screen.

georges80 · « **Reply #23 on:** March 14, 2015, 04:39:40 pm »

I bought a Maynuo M9812 last year. It's a great piece of kit and I use it nearly every day as a load while testing my LED drivers (no more getting blinded). I do have to sometimes add/remove/change external capacitance I add to the load to 'stabilize' the driver, that expects to see a dynamic load with LED characteristics versus a more resistive based load. The M9812 does have a "LED" mode, but that really doesn't appear to mimic a true LED correctly.

I've used it for some battery runtime tests to characterize their discharge curves at the loads I plan to use. Very useful to log it all to a laptop via the serial interface. I threw together a simple level shifter versus buying (or making) and optically coupled interface. At my low voltage DC test levels and a laptop I have no need at present for the isolation.

The Maynuo software is quite functional - though I only use it for battery discharge logging.

The displayed/measured voltage/current/power is remarkably accurate for such a device, so all those "digits" of resolution are actually quite useful.

If you do quite a bit of design work and require a load, as the OP stated, you'll use such a device a lot more often that you think and will kick yourself for not purchasing one a lot sooner...

cheers,
george.

Thomas · « **Reply #24 on:** March 14, 2015, 06:43:30 pm »

Quote from: georges80 on March 14, 2015, 04:39:40 pm

The displayed/measured voltage/current/power is remarkably accurate for such a device, so all those "digits" of resolution are actually quite useful.

That's my impression too.
In addition, mine has adjustable filter response (I guess they all have?). That enables trading response time for noise.
I made the response faster without adding any noticeable noise. So now I have 5-8 "readings per second" (actual difference in measurements on each display update, I don't think the display update rate changes), up from 2-3 with the default settings.

In summary, the filter can be adjusted from ridiculously high update rate with lots of noise down to painfully slow response with no apparent noise.

I have to say I am pretty impressed with this unit, the build quality and user interface (firmware) seems very good. That said, I'm not very surprised having seen Dave's and Gerry Sweeney's reviews before buying.


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Author Topic: New toy: Itech IT8512+ Electronic Load (Read 32727 times)

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