Mini Review of ZHIYU ZPB30A1 110W DC Load 0-30V at ITTSB Blog

[Kiriakos GR]

CHAOJINGYIN Electronic, LTD.  This is a ghost brand at mainland China, in simple words this is simply a label.

True name of factory made this CJY 12V 0.20A 60x60x25 this is unknown.
Practically and this ZHIYU asshole this is also anonymous with out contacts email.

When you do marketing, and mention DELTA or NMB Technologies Corporation DC fans, you have to deliver them....
CJY 12V 60x60x25 worth qty of three for 1$ US.
 

DC Fan specifications CJY 12V 0.20A 60x60x25 Delivered by ITTSB blog due visual inspection and electrical measurements.

Operating voltage: 5V - 13.8V
Fan type : single bearing  ( dual bearing translates to identical thickness of axle at both ends,  Good example this Sanyo Denki pictured bellow) 

Operating current labelled as : 0.20A  = 200mA  = (Actual at 12.0V)  =  218mA

RPM at 12V = 6650
RPM at 13.8V = 7400

Number of blades: Seven
DC fan weight: 52 grams

[Kiriakos GR]

ZPB30A1 DC load this includes input voltage (Power supply) monitor, this able to activate Alarm condition.
 
According to ITTSB Blog electrical measurements, safe input voltage range this is 10.8V ~ 13.80V ( 13.92V this triggers upper alarm condition "Err6" ).

While average current consumption at idle this measured at 62mA, at self test and power up, Max current consumption this is varying according to input voltage.
Max current DC fan at full speed:
12.0V = 382mA
12.8V = 400mA
13.5V = 420mA
13.8V = 450mA     

It does not require much of imagination to understand that stabilized 13.8V power supply this is required ... if you expect to get highest performance from DC cooling fan. 

EXFET Power MOSFET
IRFP260N
Data Sheet - IRFP260N

60W version this using IRFP150N
Data Sheet - IRFP150N

[Kiriakos GR]

The long waited complete performance chart by ITTSB Blog this is ready for all to view and share it with the world. 

110W model it does deliver a higher performance than 60Watt version.
My applications are many:
1) 12V battery testing ( ups  batteries evaluation ) this can be served well .
2) 24V (a pair of two 12V) batteries  they are not stressed enough by this 110W load, but capacity measurement this is going to be accurate and useful.

Therefore and for the money,  ZPB30A1 110W model this is theoretically a good option.

In a later time I am going to deliver content relative to real stress tests, so to verify if limits set in firmware, these are what this DC load it can truly deliver.

[Kiriakos GR]

Here are my results after electrical evaluation and temperatures evaluation of ZPB30A1 110W.

Two major points of interest were charted down by the help of several advanced multimeter and quality software for data logging.
Two U1272A loaded with Bluetooth transmitters’ these sends consumption measurement and temperature measurement to windows PC this loaded with Bluetooth 4.0 module, and all values recorded simultaneously.
Only such advanced Data logging setup it can deliver by highest detail measurements which their analysis deliver answers in the eyes of an expert.

 
Regarding circuit power consumption among with cooling fan consumption,  while total consumption this is not extreme,  when we need to act as to be electronics engineers that we have to make a choice about power supply sizing,  we need to take in to consideration DC motor inrush current and heat generated by the power supply at specific load.
My own quick answer and suggestion this is 1250mA (named value - wall plug block) DC stabilized at 12V or 12.6V

   
Regarding temperature related details, 110W DC load this close example to 110W incandescent light bulb. 
Therefore this is not a toy and generated heat at full load this is significant.
As is shown at the charts, dangerous temperatures for the human body them created at heatsink body at first 60 seconds of operation.
DC fan control circuit this is designed to turn off when temperature this is at 50C.
50 Celsius this is safe temperature for Mosfet but not for your hands.
When this DC load operates at full power and as soon operation task this is completed, it is safe to touch the heatsink after a minimum of 15 minutes of inactivity (cooling down period).

In conclusion, according to electrical performance tests which I did, this 110W DC load it does deliver 111.5 Watt at highest voltage setting 25 Volts.
Therefore named specifications’ they are true and sincere.

Regarding product assembly I did discover several issues regarding careless job.
Mosfet screw was not properly tightened and thermal compound was not installed with care.
DC motor came with a long metal pin (attached to motor magnet).
Solder wire residues found under the PCB which I had to remove for safety reasons.

My advice to any one whom care for details and long term reliability, this is you inspecting thoroughly entire product, prior using it.
Inspect entire PCB regarding soldering quality, tighten screws, remove cooling fan for a basic inspection.

ZHIYU informs that this product should be used by a trained individual, and inspections which I did, these are obligations of a trained individual.

While I am now very happy about what my New DC load can do (performance and features), first small disappointment, this is that I am now aware that it is not possible so me to replace common cathode LED red digits with similar at blue color because these have tree times higher consumption and also require higher working voltage.

Project which I am currently engaged with, this is improving stock heatsink and DC fan, and to add this DC load in to a metallic enclosure.

[Kiriakos GR]

Gentlemen and Kids    I am happy to report that at the pages bellow you will admire pictures of my work at making an truly professional grade prototype enclosure for ZPB30A1 110W constant current DC load.

I did take this mission tremendously seriously, and what you are going to watch they are steps which was planed with much of thought and study.

ZPB30A1 110W regarding cooling solution this is average, and this 60x60x25 DC fan waken in me memories from the times that I was playing with Pentium Slot-1 CPU, and back them we was looking for magic air cooling solutions and best one was Alpha (Japan) P3125.

Today my experiences by been one ancient Over-clock-er ( Pushing high CPU cycles above default but with safety) nowadays helped me to predict best air flow path so this 110W load to work happily even as enclosed in to metallic box. 

Therefore here are details of this new adventure of my, and be aware that steps bellow they are not easy to replicate, but the glory belongs to the one who are not afraid to try.

Part 1  ....  Title: Wiring details.  

[Kiriakos GR]

Part 2  ....  Title: Wise power supply selection.

MITSUMI SR296 T2AH250V Switching power supply this belong in the era of 2009, but still this is a superior Switching power supply with:
a) ADJ 11~13V
b)  Noise Free
c)  Made in Japan.
d)  12V rail this is 1.8A.

By setting it at 13V now this will become an truly reliable power source for my new project. 
 

[Kiriakos GR]

Part 3  ....  Title:  Parts installed in to enclosure ( Inner view ) 

By the amount of pictures posted bellow, I do not think that is required further explaining my choices due text. 

Mitsumi switching power supply it did deliver 12.999 V DC when pot adjusted at max output, and everything gets powered by 13V.

[Kiriakos GR]

Continued...  Part 3  ....  Title:  Parts installed in to enclosure ( Inner view )

[Kiriakos GR]

Part 4  ....  Title:  True Heavy metal story

I thought to present few backstage details relative to remodeling that I am doing to this old ups case, and I am talking about the top cover which this needs more effort so to be transformed enough and become compatible to specific project.

Round ventilation grills these are for 60x60 DC fan.
Square grills, they are part of a top cover of an old VCR, lots of precision jigsaw work but the result it is fantastically good!

Currently I am up to add second and last ventilation grill, metal case this is softly sanded and prepared for a new paint job.

I could avoid demonstrating this step which I describe as heavy metal job    because parts look ugly at this stage, but then changed my mind, because this is quite educational material for any one interested to follow my steps. 

When I will finish working with this top cover, it would look and be a NEW 99% Perfect part from every aspect. 

[Kiriakos GR]

I wanted last set of my pictures relative to my new case, them be spectacular but all people experts with digital photography they knew this is close to impossible when subject this is black.

Today August 21, 2017 my own ZPB30A1 110W constant current load, this is ready to serve it purpose.

All details matter to me is well taken care of.

1)   Power supply:  Best at it class and adjusted at 13V, rated current 1A, output maximum current 1.8A, all specifications’ are about a not actively cooled PSU.  At this application one 90x90x2.5 DC fan this rotating at fixed 2000 rpm (according to input voltage), this sends gentle waves of cool air even to PSU.

2)   New DC fan added to ZPB30A1 110W heat-sink, specific heat-sink design supports 70x70x25 DC fan and stock fan were 60x60x25 this causing lots of unwanted noise at full rpm.  My choice was to use instead EVERCOOL EC7015H12CA dual ball bearing this able to deliver as much airflow required and motor control circuit never forces this fan to operate at more than 90% of it potential in rpm ( 3800 rpm in specification but circuit never uses more that 90% of available rpm capacity of this fan, 3400 rpm the most)

3)   Additional fins over stock heat-sink they did lowered by 20 Celsius Mosfet body temperature, with stock fan and heat-sink Mosfet measured at 110 Celsius at full load. Additional heat-sink pads lowered Mosfet temperature at 90 Celsius. Stock DC fan replacement this helped in noise reduction because airflow this increased at all heat-sink surfaces (100% cooled surface). 
Second DC fan this 90x90x2.5 helped in reduction of another 20 Celsius, and now Mosfet with combined airflow this can not get warmer than 70 Celsius and still there another 400 rpm which this circuit can use, but it does not.  This translates in to a message, this saying that I have succeed to bring good balance between heat-sink dissipation capacity among with at minimum required air flow, and Mosfet this feels extremely happy at full load, and my ears are extremely happy too.


4)   Last challenge this was top cover this to not negatively influence cooling benefits in any way, grills (finger guards) all such parts were added strategically, so further improvements’ to be added  ( air funnel  - directed air flow) and over all cooling capacity this to be increased.  Now with top cover in place I am convinced that heat-sink fan this will lower further more it rpm at full load, because secondary noiseless fan will now deliver all it can at just 2000 rpm, because air flow loss this is no more.  Entire metal case this is now one air funnel!

5) Recently I got inkjet printer paper this including adhesive at the back side, now I am able printing my own labels.
Most important Error codes these are just three, and now I will never need to consult ZPB30A1 instructions’ manual. 

[Kiriakos GR]

Product review or evaluation of any electronic DC load this has some value only when this is tested in to few examples of real applications.
Good examples are discharge of 1.5V battery, 12V battery testing, and 24V pair of batteries testing.

Also of high importance, this is a high quality recording system (data logging) among with respectable in precision multimeter for volts and current, confirmation measurements’.
 
By running tests at used NICD batteries’ (1600 mAh) for power tools, I was able to come in to several conclusions regarding volts accuracy of ZPB30A1 which I received.

ZPB30A1 LED display this is capable of actually just 900 counts of resolution at up to nine volts .
And total upper limit this is 3300 counts (10~33.0 V DC)
Such display resolution this is swallow in comparison even with first digital multimeter at about 70s, this able for 2000 counts.
U1272A multimeter this is 30.000 counts, and in comparison to 300 counts of ZPB30A1, U1272A this seems as microscope. 

At specific testing in the range of 1.42V down to Cut-Off point, my measurements’ helped me to understand three details.
First detail this is how off (error %) there is introduced when voltage measurement this is stable.
Second details this is how many counts are needed for ZPB30A1 volts meter circuitry so this to step down 100mV (last digit change to a lower value).
Third detail this is sampling rate in the unit of time (Volt measurements’ per second).

Answers:

Detail No1
I got +7mV above actual measurement.
According to specifications’ Maximum voltage measurement error this is 1% or displayed value of ±0.02V at specific voltmeter.
At voltage of 1.3V (this translates to 1300 mV) expected deviation could be Max 1312 mV or as Minimum at 1287 mV.
Actual measured error in my test, this is approximately +0.6% at 1.3V

 
Detail No2
Voltage display measuring 1.26 volt stayed static when multimeter this started measuring 1.2608 volts all the way down to 1.2438, then DC load LED display this refreshed in to stable 1.25V

Detail No3
Now I will try to explain this in simple English, volt meter circuit this is almost capable for one measurement per second, this introduces smaller error at middle point of discharge curve and much higher error at beginning and end of discharge curve, because there voltage values changing much faster and voltage measurement circuitry it can hardly keep a track of all action.

Some hobbyist thought that they can use data-port of ZPB30A1 for data logging, even if it was working that way (which does not) all recorded measurements’ they would be totally worthless.
One fast multimeter as is U1272A, this does six measurements’ per second and sends one due Bluetooth module at intervals of 1 second.
Therefore complete discharge curve this gets captured by good precision and consistency and such data they worth also to be considered as proof of battery cell performance.

What I did realize or learned from my first serious experience with this constant current DC load, this is that at far more expensive programmable DC loads all consumers should pay attention of how well they performing speaking of their capability in data logging.
From my point of view a major issue this is that currently nor Bloggers nor enthusiasts thought to review DC loads in such detail.
(Internal data logging system performance and PC data, this be compared with an external data-logging monitor)   

From the other hand any electronic DC load manufacturer who claims delivery of high accuracy model, he should start delivering (free of charge) printed calibration report.
Neither last nor least, specification which must be known to future buyers this is measuring speed and measuring accuracy of measuring circuit that its model this using.

In summary,
Full size DC load its not simple gadget by exception of this semi-finished ZPB30A1 this priced 20~25 E retail with shipping.

What your money buying at Full size DC load, these are housing (metal enclosure), well performing air cooling, precise circuit this set current value, precise electrical measurements’ circuit, precise (and fast) data logging feature, and naturally long or sort product life-cycle.

ITTSB Blog this is now ready due this new pack of experiences among with it new multi channel remote data logging system, to perform worthwhile comparisons of any model or type, of electronic DC load at 300W ~ 600W.

Right now I am very happy especially of three charts below, careful review of them it does deliver combined complete set of all essential information's.

[Kiriakos GR]

Next testing which I did was also extremely educational too.

ZHIYU ZPB30A1 this demonstrated good performance here, in this specific test I did use 2200 mA as starting discharge current so to test those Samsung 2200 mAH old cells.
When two weak cells started shown their age, I was forced to stop ZPB30A1 and I did set a lower current value and I did continue,  ZPB30A1 did not lost previously recorded capacity and this continued doing it job.


Regarding voltage measurement display resolution, practically one display measurement of 14.130 this is 14 volts plus 130 millivolt.

ZPB30A1 when this measured 13.96 V, actual voltage was 14.004 V.
We use to say that Devil this hides in details and so 13.96x ( x = unseen digit) compared to other precise measurement, there is a difference of about 44mV.
By adding at the measurement 13.960 V this +/_ 1% accuracy variation, then measurement could be 14.099V or 13.820V.
Therefore in my measurement ZPB30A1 demonstrated error of approximately +0.7% when this operating at 14V. 

 
Regarding current measurement ZPB30A1 at 1A and at 2.2A this keeps adding 4~5 mA which is not significant error.
Given specification this is digits resolution of 0.01A and +/- 0.7% accuracy.
In my case the measurement of 4~5mA this is a proof of approximately 0.5% of error.
DE-208A multimeter this has accuracy specifications’ of +/- 0.5% +5 digits at DCA and it is a 6700 counts meter.