Anyhow I'm still a bit wondering what the special trace narrowing near the negative input is ... an emergency fuse I'd guess (there are no replacement specs printed on )
I am still scratching my head for that, it reminds me to a warp zone in Mario Bros...
Finally got around to checking mine today. Not good at all!!!!!!!
Erratic jumpy readings -10mV to +2mV from my 1mA source (DMMCheck Plus calibrated to 1.0003mA)
My Agilent reads the source as 1.000mA (see pic), battery in uCurrent is rayovac CR2032 reading 2.96v, changed battery to GP reading 3.27; and still the same issues.
I don't see the fulltest setup on the photos.
This is how you set up both tests, right?
yes your diagram is correct.
do you have two multimeters? That would be the best test.
Measure the current simultaneously in uCurrent and your best meter.
Else put a resistor in series with both tests, say 1 ohm, maybe the problem is that the current source in near it's limit.
Used two DMM's Agilent hooked up like before reading mV from the Volt output side of the uCurrent.
From DMMCheck I+ to uCurrent+,
uCurrent- to RatShack+,
RatShack- to DMMCheck-
RatShack reads 1.00mA, Agilent mV reading still all over the place-+
Note: I got the 1.00mA reading no mater the position of the uCurrent power switch (off, on, short)
Hi,
I had a good look at the photograph of the board.
I suggest that you check the solder connection on R9:
Remember, I am looking at the photograph, not the board
Jay_Diddy_B
Found mine in the mailbox today. Package looks entirely undamaged, have to test the device later this week. Thanks Dave!
I have the serial number 555, after number 1 probably the best number an electronics nerd could wish for
In this pic, R9 looks ok.
Reflow R1 and clean the switch as well, using a good contact cleaner. and then operate it about 5 times end to end to get the wiping contacts clean. That should help.
There is what looks like a cracked solder joint on R1 sense lead, which would cause this error. If more units have this then it will need attention. Will check my one when it arrives ( hopefully real soon now) in the post.
My unit number is 47, my understanding is that it was to be built and tested by Dave him self.
It's a bummer that I got a DOA unit, anyone know what the warranty on this thing is?
There is what looks like a cracked solder joint on R1 sense lead, which would cause this error. If more units have this then it will need attention. Will check my one when it arrives ( hopefully real soon now) in the post.
Good eye, I've posted a few pic; where you can see it better.
Dave did point out this on the first batch. This must have been one which was marginal and cracked during transit. AFAIK this issue has been resolved with later production units as they tweaked the process to take care of it.
Dave did point out this on the first batch. This must have been one which was marginal and cracked during transit. AFAIK this issue has been resolved with later production units as they tweaked the process to take care of it.
The crack must have been there all time.
Is it due to to little preheating ?
Would a x-ray shown the crack ?
Is it working now?
No, it's not working. I've hit it twice with the solder gun and still it bounces around.
Is this leaded or lead free solder?
No, it's not working. I've hit it twice with the solder gun and still it bounces around.
Is this leaded or lead free solder?
Lead free.
Sorry you got a dud
Obviously it would have passed the tests ok.
I can't see anything wrong with the solder joints, but 2D photos aren't very useful.
The only other thing I can think of is that the assembler has reported a few dud switches, so perhaps that would be it. I have not investigated the exact mechanism of the failure yet though.
If you can confirm that then I can ship you some replacement switches. Heck, I'll ship you a replacement board, email me your snail mail address.
No, it's not working. I've hit it twice with the solder gun and still it bounces around.
Is this leaded or lead free solder?
Lead free.
Sorry you got a dud Obviously it would have passed the tests ok.
I can't see anything wrong with the solder joints, but 2D photos aren't very useful.
The only other thing I can think of is that the assembler has reported a few dud switches, so perhaps that would be it. I have not investigated the exact mechanism of the failure yet though.
If you can confirm that then I can ship you some replacement switches. Heck, I'll ship you a replacement board, email me your snail mail address.
I switch to uA range and my DMM to V (not mV range) and got a reading of .9995 My source is 1.0003mA so:
1.0003mA (+/-)0.05% = uCurrent output of 0.9998V - 1.0008V
Then you add in the meter (+/-)0.05%+5 count you get a range of:
0.9988V - 1.0018V. So if my math is right; in the uA range I am getting a reading within the limits of the uCurrant and my Agilent U1272A DMM. It is just not working right in the mA range.
Hi
Got my µCurrent today in germany.
Unfortunately I got the tombstone edition!
The banana connector screw is tightened but the circuit board is slightly too thin.
It's #1043. Sent 8/4/14.
Cheers
Hammy
Hi
Got my µCurrent today in germany.
Unfortunately I got the tombstone edition!
Wow, look at that led... I'm sure it was not in Dave's functional test bench but still, wow...
New note to the test bench person. Check the darn light works along with the other testing.
Dave I sent you a PM a few days ago with my email and shipping address. Is there anything I could do? A specific test I could do? to help you determine what is wrong.
Hello,
Got my uCurrent today here in Portugal
Mine arrived in Seoul. Fantastic!
Something's up with the mA range though... it's all over the show. nA and uA are good as gold.
No time to debug now, so will fire it up at the weekend weather permitting.
Mine had a loose input ground terminal and had weird readings. After tightening it, it worked perfectly.