Resistors Decade box - How to - Photo story ..

[mikeselectricstuff]

...err shouldn't that last switch be labelled either 100m? or 0.1?, not 0.1m?....?

   I had 50 Greeks electronics engineers ( on another forum ) debating on that ... about the ultra correct description.

And no one win ... 

Yes but 0.1m? can't be right - it should be either 100m? or 0.1?

So we ended up to agree , that we have to accept the labeling on the resistor as guide.
Its an  0.10 Ohm  ones ,    equals to  9 X 0.10  = 0.90 Ohm  =  1 Ohm minus  0.10 mOhm 

And the wiring looks quite thin for a box going down that low.

This is an  copper wire with silver at 1mm ,  more than enough  for an low current circuitry,
like  0-250 mA  .

I was thinking about its effect on resistance accuracy, not current-carrying capability, although switch contact resistance may be a more significant effect.

[Kiriakos-GR]

Hello jimmc ,  its possible to be my fault , and I was not clear from the start.

I did not copy or recreate the exact 'Waidner-Wolff' schematic , its just an rough idea of how I connected my resistors ....

And as I explained and above ... the main concept are the " decade " box.

The total resistance of the all box , all stages included  ,  are 00,04 Ohms  ( 10,00 ohm range).
So if I enter the first stage in , I get  00,14 Ohms.  
And then goes  00,24  00,34  00,44  etc etc

I have not measure yet the "quick exit" resistance = the three first stages,
I was busy up to now testing the reference DC source.
  

[Kiriakos-GR]

Ok did my testing about the input volts at the reference chip .
After my second tests , I can verify that it stabilizes to 10V  with just  10.80 input voltage.

I tested the input voltage VS mA consumption ( important factor for my battery source )
And found  that the chip and the LED,  they draw 2mA at 12 volts input , and almost 2,5mA at 15V ,
so I removed the one battery , and now they are 4 by 3V its one = 12v  (12.34 actually )  

The output, it continuously fluctuate like  10,000 - 10,001 in both 20.000 count Fluke meters.

In the last of the three pictures ,  its my home made  battery holder , and I added one 100nano capacitor,
in the input of the TL Chip, so to comply 100% with the reference schematic.  

[Kiriakos-GR]

it should be either 100m? or 0.1?

Ok I agree , as long the 1 Ohm = 1000  milliohm , you are correct.

Thanks God , I had save the original Photoshop files with all the layers,
and the change  will be a piece of  cake .  

I will print it tomorrow.  its 2 am here .... at 6:15 I have to get up 

[allanw]

That's a lot of Fluke 80x0's you've got there. Have you considered a HP 3478A. They go for at most $150 and are way better. Or the 3468A which is under $100.

[Kiriakos-GR]

That's a lot of Fluke 80x0's you've got there.

Well it has not planed to get that many,  but now I am happy with them .
And they are more than good for my needs. 

[eternal_noob]

How-ly it's looking good Kiriakos. I have made a resistance box too,but it's not anywhere near this. I used cheap rotary selectors from china and 1% resistors. It is more than adequate for my needs and I'm glad I built it.

[Kiriakos-GR]

Hello @eternal_noob and welcome ..

Well I had found on ebay , ready made Decade boxes from China at 60 Euro .. (shipped)
But It was not an true solution. ( low manufacturing quality )  

Because there is allot of labor involved at making one decade,
also the quality of the components has an primary value, so worth at the end ( trouble and money) .

About the 1% resistors ...  well, even at the expensive 0.1% , I noticed that the lower values,
are more stable and accurate than the high ones .

I had also use the 1 Ohm range 1% resistors and they are fine.
From 100mOhm  up to  1K Ohm , I had no problems .
At the x10K stage  only two resistors was a bit off , of the ten , and at 100K  7 of the 10 was off ( yes 0,1% )  





  

[PetrosA]

Very nice looking work, K.

[Zero999]

It seems like you paid far too much, you can buy the components for much cheaper.

0.1% resistors cost £0.15 (0.18 EUR) each at my local supplier (although they don't have <10R you still save a lot), even with 17.5% VAT they're still cheaper than the ebay supplier which might also be selling knock-offs.
http://www.rapidonline.com/Electronic-Components/Resistors-Potentiometer/Metal-Film-Resistors/0.4W-0.1-25ppm-Precision-metal-film-resistors/83009

1% resistors are even cheaper but you have to buy in packs of 100.
http://www.rapidonline.com/Electronic-Components/Resistors-Potentiometer/Metal-Film-Resistors/MF60-0.6W-1-Metal-film-resistors/30822

Rotary switches cost £0.70 (0.84 EUR) each.
http://www.rapidonline.com/Electronic-Components/Switches/Rotary-Switches/Rotary-switches/30304

EDIT:
Corrected currancy conversions)

[Kiriakos-GR]

It seems like you paid far too much, you can buy the components for much cheaper.

0.1% resistors cost £0.15 (0.13 EUR) ..........1% resistors are even cheaper but you have to buy in packs of 100..........  Rotary switches cost £0.70 (0.58 EUR) each.

I know that I payed allot for the resistors , but this is the effect of what called as monopoly ..
No choices  =  high price .
And funny enough , also some ebayers from USA , was charging that high.

Even so ,  I think that I got " lucky " ...at list I found the parts that I was in need.

For the only thing that I can not complain, are the build quality of the switches that I got.

Thanks for pointing out this sources , it could be useful to some one.  
 

[Kiriakos-GR]

I was hesitating to post pictures of measurements with it ...
Because  the " decade "  it looks to me as the " master cheater device "  ..        

You name it ... I can fix the value ...  

Any way, seriously its fun playing with it .

I did the final measurement of the inner resistance of it ...
I even clean the banana plugs with clean alcohol ..  

Its an 0.02 at the " quick exit"  point ( three stages)
and 0.04  at all seven stages.
The 0.04 divided by seven gives an 0.0057 value ,
the specs of the switches  was saying about 0.005 contacts resistance.
So by removing the hypothetical contacts resistance,
I have the resistance of the wire =   0.0007 X 7 =  0,0049 .

I think that I had come very close to all parts specs,
and this numbers  are my reinsurance , that I did not drill an hole in the water ( Greek phrase ) ,
( attempt with out result ) .

And so, this is the last images from this project ..      

Now I got in trouble.  
I need an small hard case for it , so to keep it protected , from dust and bumps .  

 

[orbiter]

All your hard work certainly paid off Kiriakos. Well done on a great project. It looks fantastic.

[abbtech]

Nice job, I was surprised to read that the labels were just printed on a home printer.

[Kiriakos-GR]

My next project would had to do with capacitors , not actually an decade ..  

More like some standard values ,  with banana plugs in a star shape , and everything  inside in an crystal clear, plexy glass case...  

I will say more , when I will take the decision to make it ..  


 

[Jon Chandler]

Awesome job...looks beautiful!

My attention span is somewhat shorter<g>, so I've used a different approach for my needs.  I use a 10-turn pot which is useful for things like providing a variable voltage to an ADC input.

http://digital-diy.com/home/handy-tips/235-simulating-analog-sensor-input.html

[Time]

What a pretty box of resistors

[JohnS_AZ]

Beautiful and well done project.
You got some nice coverage over at Hacked Gadgets

http://hackedgadgets.com/2010/09/04/diy-resistors-decade-box/

[Kiriakos-GR]

Beautiful and well done project.
You got some nice coverage over at Hacked Gadgets

http://hackedgadgets.com/2010/09/04/diy-resistors-decade-box/

You are welcome , but you need to add my full Name as:
 Kiriakos Triantafyllou  from Volos - Greece ,
an 40 years old  Industrial electrician knowledgeable at electronics repairs.
(And my contact email ... )  kiriakost@freemail.gr

Usually any such " sharing " is done by permission ,
if you add the above info , you have my permission.   
Thanks.

[alm]

You are welcome , but you need to add my full Name as:
 Kiriakos Triantafyllou  from Volos - Greece ,
an 40 years old  Industrial electrician knowledgeable at electronics repairs.
(And my contact email ... )  kiriakost@freemail.gr

I doubt that Johns_AZ was the one that posted this, he's not mentioned at all. Sending an email to Alan or posting a comment on Hacked Gadgets would probably be more productive.

Usually any such " sharing " is done by permission ,

You posted this on a public forum on the internet, don't expect people to treat this as your private pictures. People rarely complain about some extra exposure. These blogs exist to point people at cool projects, they don't usually ask permission. People usually notice because their traffic suddenly skyrocketed. This was posted with attribution and a link to the original thread and your profile, I'd say that's as good as it gets. If people want to send you an email or find out your full name, they can easily get that information. But if you want to complain about copyright infringement without permission, I'm sure Hacked Gadgets will gladly remove this.

[Kiriakos-GR]

You posted this on a public forum on the internet, don't expect people to treat this as your private pictures.

Those pictures are available only at the registered forum members ...
And so an registered  forum member had snatch them   .

My only argument are that I am not an person,  who has an limited identity over the internet,
and so I am not " living surrounded " by an just an forum name ..

About the " snatch " , some one of our members did it .

AND SO  mister  Alan Parekh  that you are on our forum members ,
add and the rest of the " info "  in good will .  


To all , thanks for your good words , and I am happy that this project of my , helps the publicity of this forum,
and some how I am returning back ( payback) , the help ( awareness about DMM ) that I got from here too.    
 

[JohnS_AZ]

Alm is correct, I didn't place your project on Hacked Gadgets. I also did not suggest it to them, although I might have had I thought of it. I'm usually proud when those sites cover one of my projects and presumed that you would feel the same. I have had many projects picked up by other blogs and have never been asked permission.

Also, I don't think a person has to be registered here to read the forums so anyone could have copied the photos.

As Dave gets more and more popular, his website, videos, and this forum are going to get more and more exposure. I think Hack-a-Day posted about his Kindle teardown the same day he posted it.
I also believe that Alan would remove your project from his site, or to revise the reference to your name if you wish.

It seems to me that you've built an awesome project, and that kind of coverage is high praise.

[Kiriakos-GR]

Also, I don't think a person has to be registered here to read the forums so anyone could have copied the photos.

Yes and No ... yes = text   No= pictures uploaded to the EEV server .

I also believe that Alan would remove your project from his site, or to revise the reference to your name if you wish.

I have clarify my wish , and this is my only expectation.

It seems to me that you've built an awesome project, and that kind of coverage is high praise.

The highest praise , are to own one ...   
And to be publicly verified ( world wide ) that it works ........    

[abbtech]

Also, I don't think a person has to be registered here to read the forums so anyone could have copied the photos.

Yes and No ... yes = text   No= pictures uploaded to the EEV server .

I also believe that Alan would remove your project from his site, or to revise the reference to your name if you wish.

I have clarify my wish , and this is my only expectation.

It seems to me that you've built an awesome project, and that kind of coverage is high praise.

The highest praise , are to own one ...   
And to be publicly verified ( world wide ) that it works ........    

Hi Kiriakos,

I just saw the comment you left on the post I did over at Hacked Gadgets. Sorry I didn't know about your concerns that you posted here about the article. I have added the information that you requested, I didn't add your email address since that would just lead to a ton of junk mail. If you really want it in there I will do it though...

Please note that attribution was always there linking to this forum post so readers could get more information if they desired and I also linked to your profile using your forum name so there was sure to be no confusion that you built it.

I wasn't trying to steal your project or anything like that, I was just sharing it with the readers of Hacked Gadgets. I am not sure if non-registered members of the forum can see the pictures or not since I am a member and actually did post some feedback you you on this post.

Regards,

Alan Parekh
http://hackedgadgets.com

[Kiriakos-GR]

Thank you Alan ,
I did take the time to have an look and in other presentations at the " hackedgadgets ",
there is interesting stuff in there .

Regards