ITTSB.EU Blog Forum
Components Testers: LCR Meter | Function generators | Programmable DC Electronic Load => Digital load DC / AC => Topic started by: Kiriakos GR on June 20, 2017, 02:32:08 AM
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Intro: Constant Current Electronic Load ZPB30A1 this is a special cost effective product originally designed for industrial use.
ZHIYU (brand / maker) designed this Load for the application of cost effective multiple testing of all sort of chargers at production facilities.
The idea this is multiple ZPB30A1 to be used in testing cabinets and be used for Aging tests of chargers ( phone chargers, USB chargers or other).
Second application this is battery evaluation and capacity measurements.
In both cases and because test results are of high importance, ZPB30A1 Load this it does maintain operating settings, operating condition, and collected measurements even after power failure, and as soon Mains power this restored, ZPB30A1 continue the job until scheduled operation this gets completed.
First ZPB30A1 this designed about two years ago at 60W, according to my estimation within 2017, old customers of ZHIYU they request something more powerful and this generating less heat at long in duration tests.
New ZHIYU ZPB30A1 V2.8 110W 0-30V this is now looking truly interesting even for ITTSB Blog, this serving as testing gear in my workbench.
ZHIYU this is simply one location in China, so far I was not able to locate any website of this small maker.
Either way, this load at 110W with improved firmware among with heat-sink and better fan, this is very promising to handle real work.
For a price of no more than 25 Euro this is able to be used as substitute of by far more expensive programmable electronic DC loads, in the price range of 300 Euro or about there.
Additionally any one whom own a good quality multimeter with data-logging he can use this among with ZPB30A1 and create battery discharge curves of high precision.
Upcoming Mini Review of ZHIYU ZPB30A1 V2.8 110W This is going to be an exploration of my at discovering true potentials and electrical specifications.
Most to all Asian sellers they continue to mention 0-30V 0-10A but such are not real specifications of 110W model. ;)
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I did a great find 8) some one from Latin America he did a chart of 60W Electronic Load ZPB30A1 V2.6 and he record Ampere output per its volts setting.
I am going to do the same for this 110W product version, and this comparison will be of great interest for many people. ;)
According to 60W Electronic Load ZPB30A1 V2.6 electrical accuracy specifications are:
Maximum capacity test error :
At 0.5A = 2.5%
At 2A = 1.5%
At 5A and above = 1.2%
Voltage measurement error :
1% + - 0.02V
Changes Log for 110W :
New Delta high speed dual bearing fan
Higher cooling redundancy
More suitable for long hours !
I am professional electrician, I have the awareness that a better performing DC fan, this change it does also changing DC power supply requirements for the new 110W circuitry.
ZHIYU maker always advice PSU for 60W PCB circuit this to be at 0.5A of greater.
An higher performing DC fan will require higher energy consumption.
Therefore and possibly, for 110W model, required power supply this would be 1A as minimum requirement.
Best power supply for stable operation of ZPB30A1 in all conditions of operation, this is something that I am going to explore too.
According to DELTA DC fan website, AFB 50x50x20 series comes in four versions at 12V DC:
RPM ---------- Consumption in Ampere
4000 = 0.06
4800 = 0.07
5600 = 0.10
6400 = 0.14
7400= 0.16
Inrush current this is triple at start up.
Therefore just for correct operation of DC fan, 0.5 A this is required for the fan alone.
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Here I am starting to explore LED display components.
Three digits LED this is SP420361N 1534 0.56 inch
Four digits LED this is SR420361N 1549
http://www.arkled.net/ (http://www.arkled.net/)
The all idea, this is if I can find compatible with a larger dimensions this to be replaced.
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While arrival of my load PCB this can take several days, I am feeling allot of enthusiasm about this project !
In my planning this is to create one high quality enclosure for this PCB, and professional grade cables and connectors for it.
For example I just discovered one pair of Kelvin type clips designed for battery Lead Acid, this usable for very small ( 7Ah ) up to larger ones.
And interestingly enough front jaws design, are flat and look good even for LCR use and even components testing.
With such clips at hand, I will make one foolproof set of cables, this will use 4 wires connectivity, and will be 100% safe regarding short circuit accidents.
http://www.ebay.com/sch/m.html?_odkw=&_ssn=mxqtech&item=301697783899&_osacat=0&ssPageName=STRK%3AMEBIDX%3AIT&_from=R40&_trksid=p2046732.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=100A+Crocodile+Alligator&_sacat=0 (http://www.ebay.com/sch/m.html?_odkw=&_ssn=mxqtech&item=301697783899&_osacat=0&ssPageName=STRK%3AMEBIDX%3AIT&_from=R40&_trksid=p2046732.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=100A+Crocodile+Alligator&_sacat=0)
I liked them that much and got three pairs. 8)
Speaking of output connections :
No rule forbids having in your enclosure in parallel connections of both.
Banana binding post ( 2 x 20A & 2 x 5A female (voltage sense) ) among with 4Pin Male & Female Panel Chassis ( for battery type Kelvin clips )
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ZHIYU ZPB30A1 while this is original developer of 60W and 110W and proof this is that they are capable of firmware developing.
Some one from a near by village in China acted as copycat at 60W model, and now this copied product gets marketed as TX6880DH.
I am professional electrician and I have no faith to any copycat design, especially speaking of electrical specifications.
ZPB30A1 product design comes with relaxed electrical specifications speaking of accuracy, and I do laugh when hobbyists trying to verify accuracy by using all sort of trash digital voltmeters 5$ worth at eBay, or by them using multimeter of 20$ retail.
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I am good at search and destroy ;D 8)
ZHIYU this is actually a maker (individual) selling his goods due Taobao (Chinese e-shop engine)
He does this job for sever years ( 2010~2017).
ZPB30A1 60/110W home page : https://world.taobao.com/item/40366570328.htm?fromSite=main&spm=a312a.7700824.w4002-1824672704.35.66c81f35RbAuvr (https://world.taobao.com/item/40366570328.htm?fromSite=main&spm=a312a.7700824.w4002-1824672704.35.66c81f35RbAuvr)
New ZPB30A2 this is dedicated to battery discharge 20V 20A 100W and includes internal battery resistance measurement mode.
https://world.taobao.com/item/550235620115.htm?fromSite=main&spm=a312a.7700824.w4002-1824672704.80.66c81f35RbAuvr (https://world.taobao.com/item/550235620115.htm?fromSite=main&spm=a312a.7700824.w4002-1824672704.80.66c81f35RbAuvr)
ZPB30A2 externally looks close to identical with ZPB30A1 , but the magic this is inside the firmware.
Speaking of firmware this maker it is smart, according to warranty policy, this device (control chip) has internal counter of firmware uploads.
This translates no warranty coverage if cause of damage this is due your toying with the firmware.
Now few important tips:
1) ZHIYU this selling 12V 1A PSU for this Kit.
I am now thinking to buy and a second unit, for running tests (benchmarks) simultaneously.
This translates that two of such units they will need 12V 2A.
2) Regarding enclosures for ZPB30A1 and especially for 110W version, use of plastic material this is forbidden.
Imagine one 100W light bulb enclosed in to plastic box, they are significant chances this to melt (dis-form).
Therefore for a single or two 110W units, enclosure this must be aluminum ( metal construction ).
Aluminum or metal enclosure, this must have equal characteristics speaking of ventilation to product design of sound amplifier 2x150W.
3) I also discover part name and picture of this two pole connector for battery voltage monitor (sense volts) .
XH2.54-2P
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Unboxing today of those low cost 90mm Kelvin type battery clips. ;)
I am happy that I spotted them even if they are not marketed as Kelvin but they are.
Build quality it is not bad, neither fantastic.
There is no branding over them, springs are very tight (lots of force), for charging up to 25A or discharging a battery they look as good enough.
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Here it is another step of progress speaking of Kelvin Clips for battery testing and capacity benchmarks.
My DC load this is still on mail after 34 days, even so I thought to finish the construction of the high power cables.
As you can see from the pictures, there is no major degree of difficulty. ;)
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Good news after all, my load this shown at the Greek borders today after 38 days of inactive tracking code, therefore it is not lost, but delivery will take more time.
Now my eye caught few details regarding heat-sink and weight, and I did one first research.
110W model this comes with heat-sink of 100 grams more weight than 60W version.
60W: 170g
110W: 270g
100 grams of additional aluminum this is allot of metal, and also allot more surface speaking of Air-cooling.
According to stock pictures 110W heat-sink this looks to be:
a) 68mm Wide
b) Plus 10mm taller (77 mm VS 57 mm (60W)
c) Plus 10mm more depth than 60W version
Sum of those differences translates to:
1) heat-sink close to double cooling capacity than 60W
2) New cooling fan looks to be 60x60x2.5
Very few people are aware that at identical rpm (5500), one 60x60x25 will deliver double CMF compared to 50x50x20 mm at the cost of 10 additional dB-A of higher noise (42.5 dB-A VS 32 dB-A).
These are impressive details , and I take few pictures for comparison purposes.
Personally I have two important questions waiting to be answered, and these are what Mosfet part code my load will come with? And also to find out more details of electric fan (product model) and real specifications.
If this comes with out labels ( everything is possible) I can and will measure rpm speed with my tool.
Digital Tachometer DT-2234C+ / Presentation & Testing (http://www.ittsb.eu/forum/index.php?topic=92.0)
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One of my goals this is to create a proper enclosure for this 110W load, many people forget that electronic load this is not a fancy toy, this is electronic device mainly producing HEAT lots of HEAT.
Enclosure size and type, and amount of ventilation all are very critical factors.
I did spotted over the internet some FAIL ideas and I thought to share them so if there is any smart people out there, to avoid them.
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My very own ZPB30A1 110W DC Load arrived today after 48 days of waiting.
I am happy about the arrival and I did all ready many tests and I have lots tips to share, but for now just enjoy the Unboxing … My first impression this is that ZPB30A1 regarding dimensions this is not something large. ;)
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After getting ZPB30A1 110W in my hands, I wanted to discover all details of DC motor fan which this came with, but my close up inspection revealed a serious QC issue.
Over the motor blades (rotor magnet) was attached one metallic pin, this be 13 millimeters long (1.3 centimeter).
I did remove the fan for further inspection, and my pictures’ speaks by them self’s.
Material this is by 99% part of one sewing pin.
It makes you wonder how this thing passed ZHIYU QC test and got a PASS sticker.
Luckily for me, I discovered the issue prior powering up the circuitry.
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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
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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 (https://www.infineon.com/dgdl/irfp260npbf.pdf?fileId=5546d462533600a401535628a2ef1fe4)
60W version this using IRFP150N
Data Sheet - IRFP150N (https://www.infineon.com/dgdl/irfp150npbf.pdf?fileId=5546d462533600a4015356286d121fd6)
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The long waited complete performance chart by ITTSB Blog this is ready for all to view and share it with the world. 8)
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. ;)
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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.
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Gentlemen and Kids 8) 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 (http://ocmanila.tripod.com/reviews/coolers/p3125_vs_vos32/page2.htm).
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. :)
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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. 8)
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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.
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Continued... Part 3 .... Title: Parts installed in to enclosure ( Inner view )
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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 ;D 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. 8)
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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. 8)
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. ;)
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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. ;D
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.
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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.
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This is my third and almost last test about me exploring ZHIYU ZPB30A1 110W constant current load.
In this test I have use two lead acid batteries’ (2 x 12 = 24V), I was aware that both are partially damaged and what I thought as important this is mostly voltage and current accuracy comparisons.
I got pictures of before starting the test (testing setup) and a few at about 95% before finish.
I did that so all meters and DC load to be warm and accuracy this to be close as possible to real.
ZPB30A1 at 24V this demonstrated voltage difference approximately 69mV.
Just for clarification I will say that all cables (test leads) which I connect to the load they are in a length of 1.2 Meters (Metric) and copper diameter this is 3mm that is the max which banana plugs accepts to be inserted as wire gauge.
According to specifications’ such cables are capable of 18~20A for power transfer.
In comparison with regular test leads wire (10A max), I discovered that at just 1A load these they create voltage drop due resistance of nine mV.
My larger in diameter cables them creates only four mV.
ZPB30A1 this using Voltage Sense circuitry, even so I did use largest possible wire gauge so personally, to feel much more confidence.
And also such cables they can now be used in a later time with much larger in wattage electronic loads.
Speaking of voltage accuracy, ZPB30A1 this measured 22.53V (or 22.530) when HIOKI meter (±0.025% rdg. ±2 dgt), this measured 22.599V.
Therefore measured difference this is approximately +0.4%
Regarding current measurement also this is just a bit higher than selected, this measured at seven Milliamperes higher at 3A setting.
After all my tests so far, I am now a believer that ZPB30A1 this behaving quite well, but there is one more test which I am going to run to it.
This will have to do with power supply testing from 3A up to the Max, which this can deliver.
I am not going to do just a simple accuracy test at several values, but I am going to log constant current so to investigate any Mosfet drift according to temperature changes.
Here I believe that all my improvements’ regarding cooling and enclosure, these will improve performance drastically and my findings will not be comparable with stock 110W ZPB30A1 in any way.
Among with my next test results I will present and my final thoughts about it. :)
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I could never imagine that performance of ZPB30A1 110W this would be so respectable, especially when you consider how much this item it is priced for.
If I wrote a pricing analysis, by using all knowledge which I own by monitoring China and Asia in past six years, the report would be very long.
And most western people will not like it, mostly because real cost and trading price they are not even close.
Regarding specific ZPB30A1 110W, I have to admit that it did impressed me, not due it highest accuracy, but due it stability and repeatability when you set current value and output (Created Load) this measure identically.
This helped me to detect which specific settings they can force ZPB30A1 this to deliver per Ampere, a measuring value this having double zero after first digit (Example 7.002 A).
For me and my Blog, one constant current DC load this would also serve in application of electrical metrology, one reliable CC source this required for calibration inspection at my samples which I review.
As such could be multimeter, clamp meter, clamp sensor and even verification of current shunt resistors.
This latest testing cycle of ZPB30A1 110W, this has a duration of about 9 hours.
And I will do a shortcut here by not overloading your head with all those information’s which they do have greater value to me than to you.
This stable CC DC load becomes an opportunity so me to explore and discover potentials and limitations of multimeter shunt, and clamp probes.
My DC power supply this is no cheap but due age it analog ammeter hesitates to measure correctly all times, this is why I am using external DMM as digital ammeter in the past five years.
Even so, this Kenwood linear PSU PD35-10 (Made in Japan) it did demonstrated to me that it does deliver unquestionable performance even today which this is 25 years old.
Just 10mV plunge at 10A load from Non-load condition, this is remarkable.
Did you know that multimeter current shunts getting hot at about 70 Celsius? When they measuring 10A for more than 15 minutes.
In my tests I did use DEREE DE-208A multimeter and latest special AC/DC clamp current probe (for non-contact measurements), and I am thrilled of this setup performance.
From 200mA up to 10A measuring this was excellent according to specified accuracy of multimeter and probe.
I got so excited and I did improvise by sharing current probe output also with my Oscilloscope.
Visualization of the current measurement was interesting, but Oscilloscopes’ are not famous for maintain stable measurement on screen.
DE-208A multimeter strongest point, this is it ability measuring correctly from a single mV, when most handheld multimeter they start measuring from 4~6mV and above.
Final thoughts & conclusion
ZPB30A1 110W DC load this has potentials, I am glad that this does qualify to engage in more applications than be a simple battery capacity tester.
According to specifications as battery capacity tester accuracy this is rather loose at mAh & Watt / hour.
At 0.2A ~ 0.5A = 2.5% and at 2A = 1.5% and more than 5A = 1.2%
Therefore for Ni-MH or Ni-CD or Lithium or 12V ups stand-by batteries (lead acid) which all of them will tolerate discharge at 2~3A Max, expected error would be 1.5%.
According specifications’ this tester can deliver best accuracy at conditions which are closer to automotive applications (motorcycle and car batteries).
Or if you using lithium batteries pack this including several cells is parallel connection.
Conclusion,
While electronics and product design of this half finished CC DC load they are good, all people thinking getting this load, they should be alerted to not trust their eyes or demonstrate blind faith to ZHIYU and use this product right away.
I do suggest:
a) DC fan inspection by removal
b) Thermal compound inspection (unsolder thermal sensor leads for heat-sink removal)
c) Apply better thermal compound to Mosfet.
d) Buy a spare EC11 Rotary Encoder (1$ shipped), you never know when you will need it, but you better be prepared than sorry.
e) Verify with respectable electrical test and measurement equipment, cut-off voltage and current at settings which matter to you.
(For example at 1V cut-off my data logging system this recorded 0,83 and in another test about 0.90 V, therefore for accurate cut-off voltage it might needs to adjust cut-off voltage at 1.1 volt instead as fine detail correction).
Best good thing that ZPB30A1 110W this offered to my Blog, this is that I am no longer see the need of getting a programmable DC load at the price range of 400~600 Euro, because vast majority of my own testing applications them can be served well.
From the other hand all ZPB30A1 they are unfinished products, all buyers they are obligated to pay for getting an enclosure, and also them to pay for a power supply.
And also if you do hate stock DC fan (noise level at high speed) and you go for a better one, total cost this gets additionally increased.
Selection of correct enclosure for ZPB30A1 this is major challenge, neither ZHIYU has necessary skills to deliver a true well designed enclosure for 110W version which this would be used in more demanding application than the smaller 60W.
All electronic CC DC load when operates they do simile to high power hair dryer, generated heat must be released by an efficient way, and also enclosure this must be metallic.
All tweaks and modifications which I did, are original thoughts of my own, and they are very close to product design this used by manufacturers them selling finished products.
Therefore, I will agree with ZHIYU that this product should be used by experienced people (knowledgeable in electronics), for all reasons above.
ZPB30A1 2.7V this is well designed ( software features and programmable functions).
In the form of a ready product ( ITTSB Blog tweaks and improvements) this is truly a small in dimensions asset !! 8)
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One medicine this is great when there is no side-effects, but here I did detect one issue or better let me use the word irregularity.
Low cost panel meter (voltmeter & Ammeter ) this is a popular gadget, but technically ammeter connection this using negative side for the measurement.
For example DSN-VC288 10A this using also the shunt at negative side.
The problem starts when you using one DSN-VC288 10A and you are up to checking it calibration adjustment by the use of ZPB30A1.
DSN-VC288 10A this for unknown reason (product design issue ?) this will measure much less current than actual.
One regular multimeter in series with DSN-VC288 10A will measure correctly but at the same time DSN-VC288 10A measurement this will introduce significant error.
When ZPB30A1 this replaced by a light bulb acting as load, then both meters ( Multimeter & DSN-VC288 10A) they will display values much closer to its other.
Therefore my opinion this is that there is some sort of incompatibility with DSN-VC288 10A (voltmeter& ammeter) and the technology which ZPB30A1 this is using.
Or it could be and the other way around ?!
Specific irregularity will cause some trouble at people using with significant faith such DSN-VC288 10A (voltmeter& ammeter) as basic panel meter in their DIY power supply, or project.
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I noticed on picture with 3 old fluke meters, that one of them has damaged lcd, right?
And my first thought was if you are thinking to convert it with 7segment led display, I have seen relative convertion here http://mrmodemhead.com/blog/gallery/fluke-8050a-led-conversion/
Do you think that its worth, or its better to get a genuie replacement lcd?
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I noticed on picture with 3 old fluke meters, that one of them has damaged lcd, right?
My 8012A it is fully functional and LCD has minimum damage ( all digits are clearly visible ).
Even so from time to time I do ask questions to Americans at eBay about finding a spare LCD.
My limit this is 25$ for a shipped LCD ( to Greece ).
The other solution about LED display , its not cost effective for a meter with low display resolution (four digits).
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Hi Kiriakos
First. I really enjoy your blog and recognise the effort you have put into it.
I am retired Avionics engineer who now is now investigating sailplane-glider battery capacity problems. We keep adding electrical gadgets so batteries are failing.
I found the ZDP 30 A1 as a possible solution to finding the true state of our batteries.
Your ZDP 30 A1 reviews are superb and I want to buy one. Can you suggest a good supplier please?
Also, I note that there are 2 versions, 60 and 110 watts. The 60 watt version is suitable for my 12V 7AH battery tests; but you say that the firmare for the 110 Watt version is more modern and better. Can you help me with a making decision.
All the best
Les
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Hi Kiriakos
First. I really enjoy your blog and recognise the effort you have put into it.
I am retired Avionics engineer who now is now investigating sailplane-glider battery capacity problems. We keep adding electrical gadgets so batteries are failing.
I found the ZDP 30 A1 as a possible solution to finding the true state of our batteries.
Your ZDP 30 A1 reviews are superb and I want to buy one. Can you suggest a good supplier please?
Also, I note that there are 2 versions, 60 and 110 watts. The 60 watt version is suitable for my 12V 7AH battery tests; but you say that the firmare for the 110 Watt version is more modern and better. Can you help me with a making decision.
All the best
Les
Hi Les,
1) I am not going to suggest supplier because even me about getting this item in Greece, I did faced 50 days of waiting for arrival from China.
I do not recommend any one these Days from eBay, uncertainty in shipping times, this has tremendously increase.
2) 12V 7AH battery this is identical to my Honda motorcycle battery. :)
Personally I did not test 60W version.
Firmware differences this is not major, what I care about this is proper heat dissipation.
More suitable this is 110W for you application, test of 7A in one hour this is possible.
Even me I did the choice of 110W model, because my application this is mainly 12V 7AH battery in ups and even in electric bicycles (these using deep discharge battery).
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Today I did receive one notification from Facebook that this project it is now one year old. 8)
And I thought to write few words as feedback.
In all these 12 months up to date, I had 100% confidence in the regard of additional parts which I choose as peripherals to ZPB30A1 110W PCB.
Today ZPB30A1 110W PCB this has over 300 hours in operation and therefore now I have complete confidence in its and every part over this PCB.
At branded products there is warranty period, at such electronic solutions made in small labs there is no any.
In conclusion, when such a circuit this operates trouble free for over 300 hours, this works as proof of good health regarding product design and of individual passive and active electronic components (parts).
My project this is not about using one ZHIYU ZPB30A1 110W at default (stock version), this DC load PCB it is designed to be installed in to large metallic cabinet and also in to large quantities, ultimate goal this is formation of one battery tester of 50 at least testing channels.
What I do consider today as major success of Mr. Kiriakos Triantafillou, this is entire followed concept so ZHIYU ZPB30A1 110W DC Load this to become a perfect designed standalone equipment which will serve reliably over a workbench. :) :) ;D