FLUKE 8050A searching adjusting tip to set DC at 0000

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

The Voltage for the meter section is correct because they are generated by the switching power supply and it is important not to run the 8050A without batteries connected! plus the voltage of the batteries has to be correct since that will affect the -5 and -10V output. So I am not sure what happen when 7.2V batteries was used in place since the voltage of the batteries determines the voltage level into the power inverter which was expecting a little more than 4V instead of 7.2V, so we do not know as far as those output voltages are with 7.2V batteries in places. The -5 and the -10 may have gone higher also when 7.2V batteries were in place.
We will see when you try out the new LM317.

[Kiriakos GR]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

I will try to replace the LM317 with another one so to investigate this possibility too.
What made to not suspect it as possible cause of the problem, is that all the voltages in the output are were you will expect them to be.

Tom@ I did manage to use another battery type successfully for all those weeks because I was not having spare NiCD at that time, now I do have.

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

If the constant current source is which is set at 1.25Vref/9.1 oHms = 137mA, that means the 9.1 Ohms resistor will dissipate 137mA x 1.25V = 0.17 Watts. What it means is that the LM317 is not working, instead of regulating the current, that is why you are getting 300mA flowing through the resistor instead. The LM317 has 1.25V ref voltage built in. Right now the resistor is trying to dissipate about 0.8 Watts of power (300mA is flowing through 9.1 Ohms, some may still flowing through the LM317).
the whole purpose of the constant current source is to limit the current flow to the set point as determined by the resistor, the current will force though the load up to the point where the Vload cannot be higher than the LM317 Vdiff.
So if the Vin is 15V and the Current is set at 100mA, if you short out the load, the max current will still be 100mA, the resistor (12.5 Ohms) will dissipate 0.125W (1.25V x 0.1A), the LM317 will dissipate 1.375W ((15V-1.25) x .1)
By the way, when power switch is activates, the resistors are put in parallel to provide BOTH the charging current and the operating current for running the meter. See post 24.
And of course the R25 (12 Ohms) will be cooler since less current is flowing through due to higher resistance than the 9.1 Ohm resistor, those two resistor are in parallel when power switch is activated.

[tom66]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

You decided not to use li-ion in the end?

[Kiriakos GR]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

I have some updates to share.

I got some fresh 2500mA NiCD for my cordless power drill, and the old ones found a good home in my 8012A (NiCD qty 2), and the 8050A (NiCD qty 4).

What I do see as a problem is that fact that R26 (9.1 Ohm) stays very hot all the time at 74C = cooking up.
The R25 (12 Ohm) run a bit cooler at 43C, room temperature 22C .
The constant current PSU causes a constant flow of 300mA 24/24.

In the old days FLUKE could be happy with this design, but today I am not with it.
Other than the constant flow of 300mA the NiCD are all the time warm too.
The only option that I can think of is to add a second power switch so to turn off Mains completely.

[tom66]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Until he kills himself, then it is no joke. I have met several reasonable Greek people. I have also met one Greek person (not Kiriakos) who is the most unreasonable, illogical idiot ever, but I treat him as the exception to the rule.

[Th3_uN1Qu3]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Let the chairs fly!!!

Everybody, you should know that Greeks in general have a fairly short temper and hold their own idea until the end. You shouldn't get upset about it. In some cases, this can be a great quality, and it's certainly one that most of us Romanians lack, and we'd be in a totally different (and better) situation if we were more like the Greeks.

So everybody take a seat, leave this topic alone until something new happens, and let the anger dissipate.

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

And yet you still read it, LOL.

[Kiriakos GR]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Getting upset, aren't you?
"My advice move away from this thread, you are looking as Troll all ready in my eyes." Really?
It is getting funnier every minutes. Better come up with better insult!

Post Read & Ignored.

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Getting upset, aren't you?
"My advice move away from this thread, you are looking as Troll all ready in my eyes." Really?
It is getting funnier every minutes. Better come up with better insult!

[Kiriakos GR]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

"
One day some one will get hurt due to your carelessness due to your modification.

Oh really? I feel all ready as an extremist with a mini nuclear bomb in my hands.
I have the feeling that you are dieing to attract my attention, with your pointless arguments.

Also when one real professional tests a circuit for 24 hours before posting any info, you have two choices a) accept the results or b) Ignore it.
This what the smart people do.

My advice move away from this thread, you are looking as Troll all ready in my eyes.

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

"then I will take you more seriously, for now you are just a kid playing with it keyboard."
So why did you post that as an insult?
"While I do not have any need for self promotion due the Internet, I can proudly say that it was cost 600,000.00 Euros. ( Industrial system)" See? you are bragging again. I worked on Ion-implanting machine in 70's which was over a million dollars at that time when I was working at Fairchild Semiconductor. I never bring it up on how expensive the equipmemt I worked on until now since you bring it up, so stop bragging, you're not impressing anyone here, by the way learn how to read schematic before making any more modification.
One day some one will get hurt due to your carelessness due to your modification. Look at Boeing's batteries problem, some experts did not pay attention, luckily no one got hurt. French design charger system, Japanese batteries, US test and verification and it still failed. "I am as person an more intelligent temperature monitor than a thermal sensor of 0.20 $." sure.

[Kiriakos GR]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

No one said that the posters in this thread they do not have and their bright side,
the idea behind a successful communication in a forum is the different point of views.
That works as salt & pepper and makes the conversation to taste better.

From the other hand the proper way to evaluate and measure up your "talent" is just one,
and comes from the answer in the question: Which is the price of the most expensive item that a customer trusted in your hands so to repair it?
While I do not have any need for self promotion due the Internet, I can proudly say that it was cost 600,000.00 Euros. ( Industrial system)

Now it is time to return back to topic, and I will say thanks for all the received comments.
My idea works well for five days, if something goes wrong in long term, I will return back and add this info too.
I am not afraid to admit my mistakes if something goes wrong and I have prove that all ready.

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Thanks, cannot show too much, too many competitors out there. I am part of the design teams that has over 100 models out in the field since 1975.
"By my opinion you do not own even half than the understanding of Tom regarding electronics"
But again, what do I know, I do not have 'PRO' on my ID tag.

"budm when you will update your ID from Knowledge Seeker to a Pro ( in 10 years) ,
then I will take you more seriously, for now you are just a kid playing with it keyboard."
So every one, make sure to put 'PRO' on your ID, otherwise Mr. G will think you are just a kid on the keyboard and will not take you seriously.

[tom66]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Some stuff I've made

http://www.batteryshowdown.com/ - Recently featured on Channel 4 prime time television in the UK. (That's about 5.2% of UK viewers) Uses an opamp to regulate discharge current, power dumped in two FETs. Look at the schematic file, if you want to see how it works. I made the website and firmware, too.

http://www.bitbox.co.uk/news-item/te...-spirit-level/ - Coolest business card ever. Built in electronic spirit level. Based on STM8 microprocessor and accelerometer. Low cost to manufacture.

Both made while working in an internship with only elementary secondary school education. From design of schematic, layout of PCB, to manufacture. And they both worked first time!

In addition I have developed my OSD at age 16 (3 yrs ago!) which is a fully graphic video overlay generator for model aircraft based on dsPIC microcontroller (still trying to find the time to pull that into production.)

When I come back I finish my work on an audiophile/audiophool headphone amplifier which needed a cheap battery charging solution (PCB done, but I left before they could be manufactured.) I designed a NiMH charger based around an LM317, because if you need to make the charger cheap/simple, then NiMH is the way. It's a lot harder to blow up a NiMH, especially if you regulate the current.

That thing looks nice Bud! Any more projects/products to share?

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Do you why? Because you can never stop learning, not like you that pretends to know it all. So you know so much, you kill the batteries because you know so much about charging them. Did you look at the diagram and know how to calculate the constant current output from that circuit? No, would be my answer.
"now you are just a kid playing with it keyboard." Is that the best you can come up with?
"By my opinion you do not own even half than the understanding of Tom regarding electronics."
Lets ask the people in the forum, shall we?
Any one can put the word 'PRO' on the ID, so?
Is this the work of kid with a key board? This one is single channel Power relay controlled through the web from any where in the world.

[Kiriakos GR]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

budm when you will update your ID from Knowledge Seeker to a Pro ( in 10 years) ,
then I will take you more seriously, for now you are just a kid playing with it keyboard.
By my opinion you do not own even half than the understanding of Tom regarding electronics.
From the other hand Tom goes by the book due his limited experiences which he will improve in time,
those additional experiences they will help him to improvise too by using the limits of hardware with out causing a disaster.

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

Safety, what safety? "I am as person an more intelligent temperature monitor than a thermal sensor of 0.20 $." I am sure he monitors the temp while he is sleeping with the charger plugged in over night ans also the meter that he signed off on it.

[tom66]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

You also don't understand how a mobile phone charger works.

The AC adapter only supplies 5V +/-5% though at the end of the cable it can be as low as 4.5V.

The charge management IC (often integrated into the power management IC) uses a linear regulator or a DC-DC buck converter to precisely charge the cell, for maximum capacity BUT ALSO with safety in mind. It will not allow the battery to exceed 4.2V and it will also monitor the internal temperature of the cell and disconnect or limit charging at high temperatures. Also, it will not let the cell go below 2.7V and it will make sure to count the energy going in and out of the cell to estimate lifetime of the battery.

Doesn't matter WHAT you give the phone, as long as it is within its acceptable range it will charge and the safety of the cell will be maintained. If it is outside of that range it will stop charging. (Obviously too high voltage will damage the phone but within limits it will work.)

[budm]

Re: FLUKE 8050A searching adjusting tip to set DC at 0000

"I am as person an more intelligent temperature monitor than a thermal sensor of 0.20 $.'
Sure you are, LOL.