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Active since 7 June 2012  


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21
Here is and another sample of recycled aluminum with gold paint.  :P

I bet large quantity of AudioFools will not feel good after discovering this topic,  but this SCAM it is in our hands so to STOP.

Naturally this scam extends to may other similar products.
Fake BNC connectors ( eBay ) - all connector parts just from painted iron
Good quality - Male BNC plug to 2 x 4mm terminal adaptor (Taiwan)
22
Here is and the third popular SCAM candidate, the body this is entirely made of some sort of aluminum alloy  as always the worst and cheapest.
Grommet and nut from common black iron.

The splash of gold PAINT this is all over the place,  while such a banana socket this is no good for any demanding electrical application, this is great as decoration for Christmas trees instead using round balls and angels.

DO NOT JUST READ this topic .........  SHARE IT WITH ANYONE YOU KNOW ...........................
23
And here is another example of problematic design of the cheapo ones.
Probability rate of his happening also to you this is at 95%  :P
24
When you seek at eBay Made in China parts for a project, what you should prepare your self this is to get scammed.

You first problem appears to be unreasonable pricing for low end goods.
The second problem this is manufacturing quality scam,  and this starts regarding the quality of copper alloy that a banana plug this is made of.
The third problem, this is poor manufacturing design at moving parts as is the banana front isolator tube and how well this is attached to metallic nut - ring.


The first sample here this is the cheapest 4mm female banana plug for panel installation.
This is made of very low-quality Copper Alloy, inside hole this seems narrow and a male banana will get in less than 40% of total length.
Female banana body this starts as a metallic tube, at the end of the hollow part it starts the screw end,  what I did discover this is that when you are tighten the nut the master break apart for the hollow front part.

The second sample this is the higher quality banana.
This is higher quality regarding copper alloy in use, but this has poorly manufactured insulator cap and metallic ring.
The metallic nut this has anchor fins at it exterior so the plastic to hold on it.
Most reliable banana plugs makes in Taiwan they are thermally bond to this metallic nut with the outer plastic isolator (cup).
The Chinese factory instead it did use only 25% of required metal for the construction of this metallic nut.
The outcome it is obvious, all such cup insulators they get off the metallic nut and they become useless.

Naturally some one will think and say that you may use a strong glue and fix them, but this is not the problem,  the problem is that the cheater will scam several hundred of people by making a fortune and by wasting our time and money.

Yes the first sample this looks to have consistency of 75% recycled aluminum mixed with 25% recycled copper.     :P
The better sample this seems to be of Brass that is an alloy of copper and zinc, mix proportions unknown but less copper there too but not recycled metals in it.
Metal contactivity this is acceptable (end to other end milliohm measurement).
25
No matter if Fluke 8846A (DMM4050) this is a remarkable in quality and precision instrument, when it has to do with capacitance measurements’ down to Pico Farad, this requiring some help so to perform at it best.

Originally I did a web search so to discover if any manufacturer made the thought to create a special accessory for benchtop DMM, so this to be a dual banana with slots at the back as clips for capacitors installation.
Then I thought to use K-type plug convertors which I all ready have and I made the discovery that it works great for testing of unused capacitors with long leads.

This afternoon I also added in my collection a new accessory, the concept this is again an original idea of my own.
Originally I was having in my hands (a Made in Japan) Mains adapter, and then I did removed common pins and replaced them with male banana, pins spacing this is compatible with DMM input spacing.
Now I am ready to move this idea much further, but I am not going to get in details right now.  8)

Fluke 8846A this extremely capable for capacitance measurements, in theory it is enough the user to perform ZERO (math) for test leads capacitance removal.
But for truly Highest Precision at few Pico Farad you should stop using test leads and to improvise by following a better approach as I did.

My Fluke 8846A this add about 2~3 Pico Farad with out anything connected at the input terminals.
My workaround this is to plug-in this K-type plug convertor, then to use Zero (Math) and then to install the capacitor at the back of the convertor.

I did take several pictures for you to see and personally I am extremely satisfied from my results so far. 
I do not do anymore RF work and DIY Oscillators’, but I am going to use my new experiences at DMM calibration verification applications.   :)
26
This is a gift to international visitors of ITTSB Blog.   8)
Original Exclusive BMS HX-6S-A06   electrical specifications’ .
BUT THERE IS MORE ....  :)

Second gift this is Original Exclusive BMS HX-6S-A06 NOTE: From the PCB maker for proper operation.


A)
Description
Protection board for the assembly of six li-ion, li-po batteries in series.
With balancing.
Maximum continuous load current - up to 6.0A.
Maximum impulse load current - up to 8.0A.
The recharge voltage of the overcharge protection is 4.28V ± 0.05V, but in fact the balancing chips stand at 4.20V - so after balancing the voltage on the batteries will be 4.20V.
The return voltage to normal mode is 4.08V ± 0.05V.
The voltage of the protection from the deep discharge - 2.40V ± 0.075V.
Restoration of the operating mode - 3.00V ± 0.075V.
Current balancing - 45mA.
Dimensions - 61 * 41 * 8 mm.
Connection diagram included.
To activate the circuit you need to connect the charger.
The protection circuit is not a charging controller.
The required charger voltage is 25.5V (25.5V).
The charge current depending on the battery is usually 50 --- 100% of the battery capacity.

B)
Note: For the balance of balanced better consistency, try to use 25.6 V switch source to charge (since the power flow is lower than 30 mA).
Because of the equilibrium of the 1C equilibrium current at about 45 ma, and on the market most 25, 2 V li-ion battery charger, charging current is lower than 100 mA will stop, is not balanced, no electric charge came in, the battery voltage imbalance in each group.

As for the problem of voltage drop between the battery voltage and the output voltage, the working principle of this kind of protection plate is negative protection.

When it is just combined, some will have a voltage drop of 0.1 ~ 0.3V. 
Try not to use 25V power supply for the charger.
The full charge of 6 series of lithium batteries is 25.2v, and the 25V power supply will not be fully charged, and the protection plate will not be protected, so it will be charged all the time.
Long-term use will have an impact on battery life, thank you for understanding.

C)  ITTSB BLOG Comments

By truly diving in to HX-6S-A06   circuit details I am now aware that this BMS maker he is more honest that retail sellers them trying to trade this product.

PCB printed code this is very explanatory:
HX = Maker logo,
6S =Battery configuration,
A06 = 6A continues at resistive load (car 24V light bulb).


HX-6S-A06 PCB this using quad AO4406A 30V N-Channel MOSFET SOP8, these are 3.5W Max thermal dissipation its one.
AO4406A FET electrical specifications’ sheet this is very informative.
This deliver 10A when warm (70C) and 13A Max at 25C 

HX-6S-A06 Current handling this is lower when load this is resistive at 6A, another serious limiting factor this is PCB dimensions and cooling surface.
Now constant current handling at pulsing loads this increases to 8A due all four AO4406A FET in use, its one will handle 2A and this a decision for minimizing of stress factor (load sharing).

This translates that a load of 5A this will drive this PCB to 35C that is a thermally accepted value.     
Calculation time:  5A x 22V = 110Watt  
This translates to a single row of 18650, because a double row will not be able to get balanced with 45mA.   

The maker of HX-6S-A06 PCB makes also the assumption of 75A short-circuit Max current.

Personally I am going to test and verify HX-6S-A06 PCB at several operating conditions.
In the positive side of things there is an option for thermal switch at fixed temperature and this is highly important and not an option to me, because this it should be there all ready so to monitor PCB temperature.

Many people attach a BMS over the battery cells and this is most stupid idea EVER …
 
My very own application this is a consumption of 8~20mA and this is not stressful for this BMS PCB.
In a few weeks I will discover the entire truth, but one voice in me this says that I am dealing with BMS this made to handle a 100W LED torch or similar Low Drain devices.
27
I am about to improvise and make one 22V power pack,  this will serve as Travel pack for my  10V DC reference IC which it is installed at my resistors decade box.

The ingredients are 6x 18650 (I have those).
BMS with passive balancing (Price 3 EUR)
Two of 4x 18650 storage clip box (Price 2 EUR for both).
One Blue LED volt meter, among with one button switch (momentarily contact) so this to connect the voltmeter as check point.
And final addition this will be a DC/DC converter with adjustable voltage and adjustable current among with adjustable Charge Full indicator (Price less than 1.5 EUR if you are careful).

Due this opportunity and because I am waiting for some parts to arrive, for now I will add my thoughts and some pictures of the parts which I selected to use.

Especially about this BMS there is so much misinformation at the Chinese neighborhoods.
And this is no accident, most future buyers of 6S BMS these are kids planning to convert skateboards in to electric transportation gadgets, and as we say in Greece: At the kingdom of blind people the King is the one with a single eye.

In the upcoming days I will post more details about this project.
New visitors of ITTSB Blog they are not aware that when Kiriakos (Me) starts a project, end product this will be a unique product design.

My advice = Place a bookmark and visit us frequently.  ;)
28
I thought to give Bochen a third chance, mostly because of 5% tolerance specification and because similar multi-turn from Vishay and Contelec they are extremely overpriced at retail channels.
Starting from 25 ~ 65 Euros for a single pot this is act of War against consumers.  ???

My new testing application for BOCHEN WXD3-13 this is for it to work as voltage reference Trim Circuit.
And now I hope to see minor temperature coefficient drift in comparison to 3296 trim-pot clones that you can buy more than ten with a single Euro coin.

Generally speaking I did some extended homework regarding precision potentiometer, in some cases the current this passing from the wiper this should be limited and to follow manufacturer specifications. 
I am currently unaware of 3296 trim-pot and clones Max allowed current this passing from the wiper.
From the other hand BOCHEN WXD3-13 this is a 2W monster and the application of voltage reference Trim Circuit, this is actually a Zero load application for it.

I have just finished my circuit modification, now I am waiting for my air-tight voltage reference circuit to thermally stabilize, soldering heat to equalize with current room temperature that is 27 Celsius.
Two hours later I will perform a final adjustment, then I will monitor over all voltage stability for three days, only then I will be able to say if I am happy or not with the results.  :) 
29
I am celebrating ITTSB Blog seven years of activity milestone.
Blogging this is painful and costly sport but I am a fearless warrior and so there is hope.  ;D
30
I think that best way so to deploy my article and thoughts this is by adding first Using Trend-plot description of our User Guide ( By Fluke ).

TrendPlot provides a visual representation of the measured signal over time. About three-quarters of the Meter’s display is used to plot the maximum and minimum readings vertically, while the horizontal axis represents time.
The vertical and horizontal axis’ are not calibrated, and only represent relative time and amplitude depending on the input signal.


Now, as vertical separators they are Five vertical lines of four dots its one.
Horizontal Spacing between its separator to the next this is 50 pixels and 200 pixels in total (as horizontal length). 

First separator this should be named as Zero point.
Second and third separators they should be named as compressed storage area.
Fourth and Fifth separators they should be named as uncompressed storage area. 

Now according to Fluke, Compressed graph (at Second and third separators) this gets actually compressed by retaining only positive and negative spikes, this translates that vast majority of average values they get discarded.

Trend-plot sampling : This is at interval of 1:1 plot sample per second and this is as such just for the first run and before a first time compression occur.

Trend-plot concept : By software implementation of sample points collection and review of plot marks.

Trend-plot Mathematical concept : Trend-plot this is an visual representation of Min/Max recorded values, handheld multimeter they do that too by the use of small quantity of memory and they can record a)Minimum b)Max and c) Actual measurement and some more advanced DMM they include and d) Average measurement too.


What is the most well implemented Trend-plot at a graphical multimeter? 
Well GDS-310 Oscilloscope and multimeter this has the most successfully implemented Trend-plot because this is totally uncompressed, but this is possible because the user he can select a fixed duration of time from seconds to minutes or hours.
Practically there is no uncompressed Trend-plot, what there is actually this is two types of Trend-plot, GDS-310 this has uniformly compression at entire screen but when recording time exceeds User choice of time scale, all first recorded graph values they get erased and what you have this is all the action recorded within this specific selected time window.     
Such Trend-plot implementation works best so to review for example a thermostat operation in a refrigerator,  in a period of three hours it will be nicely recorded the timing in which a thermostat activates and deactivates by us measuring temperature due a K Type thermocouple.   


Best scenarios so to use Trend-plot at Fluke 8845A DMM in your benefit?
Trend-plot this is a useful secondary in value tool (when this gets compared to detailed data logging tool)  when we need to inspect stability over time of measured value.
For example I did inject 10mA of current at 400mA range of my 8846A and with active Trend-plot I did discover that 8846A resistor current shunt this was needed approximately 30 minutes so temperature coefficient to fully stabilize.
This translates that when you need high accuracy at Low current 400mA range, you will have to leave the DUT working for 30 minutes prior measuring anything.      
 
Trend-plot with fixed sampling at one time per second this is not the best tool so to record inrush current.
 
Therefore best use of Trend-plot at Fluke 8845A, this is for a first evaluation of slight changes over time, best example here, this is battery charging or discharging curve.
For example a friend gave you a used NiMH 1.5V AA, battery condition unknown, you do charge this battery and then discharge it by monitoring voltage at Trend-plot.
By you constantly monitoring voltage and time duration, you may come in to a first conclusion of this battery health status.
Therefore 8845A Trend-plot this is mostly a electric power monitor, for a quick visual analysis / DUT behavior  basic review.   



Best scenarios so to use Trend-plot at Fluke 8846A DMM in your benefit?
Fluke 8846A has a higher quantity of measuring range regarding DC Low current, among with the ability to measure temperature exclusively by the use of Pt100 & Pt1000.
Evaluation of DUT power consumption when an electronic circuit this is at Sleep-Mode this is possible.

Additionally you may use Trend-plot for temperature measurements at applications that a hour of monitoring this is enough, Trend-plot graph plots compression as is implemented at 8845A/8846A this becomes less useful as data logger review tool, at higher logging time duration.


How ITTSB Blog evaluated Trend-plot 8845A/8846A behavior and capabilities ?
Well I was had to monitor Trend-plot activity for one hour, and to take more than 30 pictures with my digital camera.
Very soon I did realize that plot compression this stealing away 50% of Dot matrix display total length and the other 50% this now it does Live plot at 100 available pixels, now when these 100 available pixels get full of data then Trend-plot this updates and compress again, so these 100 available pixels to get free again.
I did manually a measurement of pixel counts between these vertical separators, this is how I got awareness of 50 pixels spacing.
Such a 50 pixels spacing this translates that Min/Max Plot this it does require a minimum of two pixels (in series), first pixel will plot a Max value and it neighbor pixel will record a Min value, therefore we have actually 25 recordings in to a 50 pixels spacing.

I did also timing recording of first four Trend-plot record / compress cycles.
Execution times was (in minutes):
1) 00:01:33
2) 00:03:03
3) 00:06:15
4) 00:12:30
This translates that while the clock counting in seconds, plot sampling interval this get double (slower) at every new cycle of operation.
Therefore you can not use recorded graphical representation so to define exact time which an event was occurred, except if you personally record on paper (take a note) of the time that this event it just  appear = Got plotted on your screen.

Yes now it makes sense of why Fluke talks about of not calibrated Trend-plot, with so many undocumented variables, a visual representation of the measured signal over time this is all that you get.   
 
Pictures below they represent:
a) Trend Plot fully expanded and before a next time compression occur.
b) Trend Plot compression just occurred and this now starts a new cycle.
c) This is my souvenir at the duration of 60 minutes.  :)   

   
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