uCurrent, German customs & first measurements

A project log for clock in hardware

as I work with people all over the globe, I need a simple way to tell their local time without hanging lots of clocks on my wall

rawerawe 09/22/2014 at 21:330 Comments

Finally, I received a letter to inform me that a parcel from Australia waits for me at the next customs office - uCurrent \o/

For German customs, you must provide info on what the value of the product is (read: all you paid for it, including shipping, transaction fees etc). If this info is not included with the parcel (e.g. because the sender has no clue what transaction fees you paid), you have to provide that info in person. Best way to prove this is to print out the relevant info from paypal, remove irrelevant info with a big black marker and run the result thru a photocopier. If "all you paid (until now)" is below approx 21 Eur, you don't have to pay any fees or taxes. For everything above that, but below a higher limit, they charge you 19% MwSt (=~VAT), but no Customs fees. If you get caught speeding on the way to a customs office, this costs an additional fee...

The uCurrent comes in two parts: PCB and housing. The housing contains the four screws and is held together with tape. Of course they had to look inside and and close it with "inspected by customs" tape, which is really sticky. Thank you -.- I'll try to get a refund from them for the time I lost removing that glue without damaging the enclosure...

CR2032 installed...

Measuring the current consumption of one of these continuous clockworks (their noise and power consumption make me go crazy...):

The power supply with the nice lockable multiturn dial (~5 Eur , flea market find) provides 0.94V, the clockwork consumes avg. 454uA. The big blue cap at the clockwork helps on averaging and provides stable readings. This clockwork consumes half a milliwatt.

"You could fly to the moon on that!"  -- Dave Jones, EEVBlog

Anything else around I can test out the uCurrent on? That cap looks like it got some leakage current...

At 6.1V, I left it charging for about 10min. MAKE  SURE TO NOT OVERLOAD THE UCURRENT SHUNT RESISTORS. The charge current settled  at 1.27 uA.

According to the following chart, this seems reasonable:

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