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ArcticMyst Security by Avery

"X-Load" A Custom 10A Testload All-In-One Unit

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May 25, 2010
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Hey Guys,



ALL-IN-ONE TESTLOAD


So i wanted to show this Test load off that i made for myself.



So the story.


I was getting so Sick and tired of dealing with DMM and testloads wires everywhere that i decided to make something more solid and compacted. Most of you guys dont really have such problems but since i make a crap load of drivers at home and test everyone it starts to become a pain.:(

So what i decided was to put everything in an Encloser and basically remove the DMM and Testload from being loose in the open.

I first decided that i would just have a Display for the "mA" But i find myself always checking the load Voltage too. So i added that in as another connector and i will put 1 display in for the mA and the other is for the Volts.

The Unit Runs off a 9v Battery and has an On off switch.

Since i cant really think of a "Good" Solid Connection that i can mount exposed on the outside of the case for the diode selector iam going to make the case close and hold tight with strong magnets so that it will be easy to open and close to change the diode selector if needed but it wont be loose enough that it will come apart. (Alot of people do this with project boxes so i know it will work just fine here.)

The only wires that will be Exposed "Drilled through the case Nicely" is the +/- to connect to the driver. Thats it and thats exactly what i wanted. A stand alone unit.


Now before i go into the pictures i want to say that I got a little excited with the "AMP" rating and called it a 20A Testload. I can say now there is No way this Testload is going to take 20A.!LOL It can take ~ 3A without a heatsink on the 1 ohm Resistor. That is the main Issue and only issue with heat really the diodes can take it pretty good but the 1 ohm resistor cant. The 1 ohm resistor gets so hot it will desolider itself.LOL It happened to my Jib Testload So i new it will happen here.

So what i did was i left exposed copper on the bottom where it was needed and i plain on mounting the Testload entire bottom on a heatsink "Then" it will be installed in the case. Even then i would probably only be able to dump around 10A into it for a few minutes.

However i designed it so that i can also use this Testload without the case and with the 4 screw mounts i can mount it to heatsink i have in mind. "More on that bellow" That should allow me to run it continuous at ~10A or possible more with no issue.

All i really wanted it a Solid 3A Testload with being able to test up to 3A-15A hear and there..... So this will be perfect.

If i need more then that then i can use the second option that is mounted to the heatsink.:)

None the less i really like how it works.! Its exactly what i thought Minus the 20A Excitement.LOL. Fail.! :na:



OK So here are the Pictures...................



Pictures:






http://s944.photobucket.com/user/La..."0" alt=" photo P6080024_zps6e01bb58.jpg[/IMG





Large Copper Plans:drool: :


Here is where the top mA display will go. The same kind of display will go on the bottom for the Volts:


This is where the 9V battery will go:



Here is the dry fit to make sure everything fits OK:



First i reflowed all the SMD Parts:


The Bottom "Note: I made sure the expose copper pad's that had solder flow through where flatten with the use of solder wick. It worked great" (nOT SHOWN IN THE PIC):



Here is the completed board:






The simple diode sellector:


Here it is in the case. Keep in mine there will be a slab of aluminium under the board. Then Screwed in:




I made some Connectors using Jeff's Silicon wire.:D I wanted it to be Flexible and tis perfect:


The connector that is in is the mA display. The other connector that is Empty is the Volt display:


Test check:


Reading check and it works:


:wave:


OK So thats what i have for now.

I would have had it 100% complete but the diodes i used i mis calculated the Forward voltage and it was too low for under 2A. Basically i tried to be able to use as many diodes as i could to spread the heat out through all of them but at 2A i was only able to get a MAX load of ~4.2V so that was too low. I need a little more forward voltage so i re ordered the correct ones and once those arrive with the Volt display i will finish the build and post the rest of the pictures.

But its done other then that.:)

Hope you guys like it so far. I do.:wave:

For those that dont understand the layout here is the Write out:


Since sevral people have asked me already privatly i might as well say it here too that Its Probably not going to be for sale only for the simple fact I dont want to step on anyones toes "Who make and sell testloads" as you guys know thats not my style or respect.:) I would rather hold someones respect then make money off something they are doing already. If others feel comfrotable selling something very similair or exactly what someone else sells then thats on them i wont do it. Even though its diffrent its the same concept. Had it been a testload more powerful that is a diffrent store but its nearly identical to what others sell already so i dont feel comfrotable selling them. "It is how i was brought up on LPF by the high respected sellers and i will always hold to that standerd" for the simple fact of respecting others even though i dont get that same respect back all the time.;) I dint get the Respect i have today doing that.:)

But i will probably hand out like 10 boards or something as projects.

Well if anyone wants it that is.LOL:crackup:



Cheers.:beer:​



:thanks: For Looking.!!!
 
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DJNY

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FIRST!!!!

Now I should go back and read your post :p


Btw, did you get a new (DSLR?) in the past months? Your pictures look even more clean than in former times!
 

Blord

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The testload looks very good. I like that dedicated meter.
If I hadn't already two testloads I would surely purchase yours.

Also the pictures look very crisp. The motif on the table matches mine. :)
 
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FIRST!!!!

Now I should go back and read your post :p


Btw, did you get a new (DSLR?) in the past months? Your pictures look even more clean than in former times!

LOL.

Nope.:) I never had a DSLR.:) This is not one either. Its my old Olympus.:)

Iam in the Market for a new camera though.:wave:


Second :)

Where did you get the ammeter?


Here is the BLue colored one:
4 1 2 Blue LED DC 20V Digital Volt Voltage Panel Meter | eBay

I think this seller also has it in Red and Green too.:)

I cant remeber Exactly who i got this one from but iam pretty sure it was this seller.

its the same display i use for my Ophir head and alot of people use it too for there meters.

It reads up to 19.999V.
:beer:

The testload looks very good. I like that dedicated meter.
If I hadn't already two testloads I would surely purchase yours.

Also the pictures look very crisp. The motif on the table matches mine. :)

Same camera as i always used.:)

I wont be selling these because there are other testloads available from other makers but i will be giving some boards out so people can make a project out of it over a weekend or something.:)

You will just need to know how to reflow but you can probebly do it all with a sildering iron since i left the copper exposed under the diodes and resissotr so you can reflow them like that if you dont have a hot air gun oven.

Its very easy.

You can also not even put the displays on and use it as a slandered Testload.

Shotgun #3

What do you mean.:D?


Looks stunning. The best test load so far IMO. Great job! +1


Thanks.:)
 
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benmwv

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Looking great man!

Reminds me of a board I made for matt ;) I'm sure that pcb alone cost a fortune. Tiny driver pcbs have me spoiled, boards this size get pretty crazy on pricing!
 
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Second :)

Where did you get the ammeter?
He's using a 20Volt DPM that reads the voltage
drop across the 1 Ohm SMD resistor at the
bottom right of the PCB just like we do with
a standard multimeter...

@ lazeerer..
Looks nice and clean...


Jerry
 
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djQUAN

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Now before i go into the pictures i want to say that I got a little excited with the "AMP" rating and called it a 20A Testload. I can say now there is No way this Testload is going to take 20A.!LOL It can take ~ 3A without a heatsink on the 1 ohm Resistor. That is the main Issue and only issue with heat really the diodes can take it pretty good but the 1 ohm resistor cant. The 1 ohm resistor gets so hot it will desolider itself.LOL It happened to my Jib Testload So i new it will happen here.

you can use a lower ohm resistor (0.1ohm) and use a 2V FS panel meter and move the decimal place jumper so it still displays correctly in Amps. Or if you want even more current handling capacity, use an even lower resistance shunt (10 mOhm) and more sensitive 200mV FS meter. :D

As for thermal connection to a heatsink, an option that is less permanent than thermal epoxy (something like this but cut a little thinner could work.
 

ped

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Yeah, The reason I ask is, I need a DPM that reads upto 30A.
 
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VERY interested in one. I don't like having my messy wires everywhere test load...Too many drivers to test. Though I could only imagine your situation...
 

DJNY

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Nope.:) I never had a DSLR.:) This is not one either. Its my old Olympus.:)

Iam in the Market for a new camera though.:wave:

Why do you want a new cam, yours takes great clear shots!

Tested out this one these days (I don´t own it): Amazon.com: Nikon COOLPIX P310 16.1 MP CMOS Digital Camera with 4.2x Zoom NIKKOR Glass Lens and Full HD 1080p Video: NIKON: Camera & Photo

It´s a very good cam for the price, also very useful in the dark - didn´t see any noise up to ISO800.


Edit: Sorry for off-topic :p


But there are also great old DSLR around, as my EOS 20D is. Should run you <$200 used. Or wait till July-August as they´re going to reduce the price of the EOS 60D when releasing the 70D :)
 
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Have you actually tested it at 20A, or even 10A for that matter? I highly doubt it will survive that without desoldering itself or popping that tiny jumper.
 

benmwv

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You could switch to a 0.1ohm resistor instead of 1ohm pretty easy. All you have to do is change the voltage divider so it reads up to 1.9999v but leave the decimal point selector in the same spot so the amps display correctly.

10w in the resistor at 10A is much more reasonable than 100w. Also the 1ohm resistor alone would be dropping 10v, I doubt any 10A driver you are making will handle a load that high :p
 
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