µCurrent GOLD on Kickstarter

[EEVblog]

This chart keeps track of daily backers:
http://www.kicktraq.com/projects/eevblog/current-gold-precision-multimeter-current-adapter/#chart-daily
It's tapering off, but hard to say what the eventual number will be.
I really need to order parts now to ensure I'm not left hanging in the breeze.

[Skimask]

Might've been more than you were expecting, but I don't remember you saying that each and every unit would be firmly shipped out by date X.

I say take your time and have fun with it rather than bust your ass trying to make everybody happy.  I think any real tinkerer can understand that.

[u271D]

Well Dave, what say you?
How do we get one of the green ones?   

[JuKu]

> so I'll now have to set up a decent test system that can be used at the assemblers...

Looking forward for that video!

[tanstaafl]

Why doesn't the number of KS backers headlined equal the number of backers if you add them up? I make it out by 9 as at 750 total backers. 13+508+200+20 does not equal 750.

Think you can back a project without choosing to get any thing back from it?

[alm]

Yep, you can pledge any amount without selecting a reward. Either because you pledge less than the lowest reward (not even enough to buy Dave chocolate) or you just don't care about the rewards. This would generally be more common with things like art projects where it's more about the project than about the rewards. Or open-source software projects where the only reward is getting your name in the credits. In this case you might as well donate to Dave via Paypal if you don't want a uCurrent unless you're desperate to troll the KS comments .

[rodcastler]

Hi!

Just backed even the bar is already at 70K only to show appreciation for the crazy aussie and all what he does.

Where's the contest for those who want to guess the final number? 

I'll go with AUD$91,598.- 

[TheWelly888]

Though I already have the older version of the uCurrent, I have just pledged AU$79 plus shipping for the latest one!

[jippie]

If you really want a fuse in the current sensing circuit (and worry less about the burden voltage), you could of course use one of those fuse holders that go in your leads.

@Dave: Are there any absolute maximum ratings (non-damaging limit) for the µCurrent Gold? What about the output impedance, I guess you want the impedance of your meter (or other attached device) higher than 100ohm/0.05%=200k? Would be nice if the absolute maximum ratings were included on the spec sheet

[Skimask]

How about a "Guess the total number of backers" contest

[SeanB]

I would guess this one will just get over the $100k mark, and considering that half of that will go as cost of goods and half of the rest as tax it still is a good result.

[DrLuke]

I'd buy one if I had a credit card and weren't broke ;(

Damn you christmas, why do you have to impoverish me every year!

[MrAureliusR]

2) R1 does not need a fuse, normally. It is rated for nominal 10A (1W) , 31A max, see Vishay specification.
But I estimate, it will desolder itself when > 500mW / > 7A are applied.

The fusible trace should blow first. Haven't tested it in practice though...

Just send one off to Photonicinduction over on YouTube, he'll be happy to put a few kA through it and see if it blows 

[fs]

Hi Dave, any chance of a few more Signature Editions?  eg: "LATE SIGNATURE EDITION" ?   I'm kinda late to the party, but would be very happy to upgrade to a higher pledge-point... you've gotta have some other stuff you could throw in along with some signed, hand-assembled uCurrents, to create another pledge level for those of that want to give a bit more money, but that have a lot less money than sense

Cheers!

[rs20]

Just to be clear about this 100x voltage mode, is the idea that you use exactly the same input terminals as normal, with the mA, uA, and nA switch effectively acting as an input impedenace selector switch? With most users probably wanting nA (10k input impedance)?

Sorry if this question is already handled somewhere!

[EEVblog]

Just to be clear about this 100x voltage mode, is the idea that you use exactly the same input terminals as normal, with the mA, uA, and nA switch effectively acting as an input impedenace selector switch? With most users probably wanting nA (10k input impedance)?

Correctamundo.

[EEVblog]

I would guess this one will just get over the $100k mark, and considering that half of that will go as cost of goods and half of the rest as tax it still is a good result.

Yes, people somehow think that 100K is a lot, it's nothing of the sort. KS and the CC merchant take $8K right off the bat, and that's on the gross value, not net profit. What's left after buying all the parts gets taxed 30%. And there are losses in the components based on the reel qty I have to buy at certain price point. Postage isn't cheap and is basically factored in at-cost etc.
Take Jeri's CastAR for example. She'll basically be making a loss (or break even if lucky) on that $1M she got. Same with many other KS campaigns.

[EEVblog]

@Dave: Are there any absolute maximum ratings (non-damaging limit) for the µCurrent Gold? What about the output impedance, I guess you want the impedance of your meter (or other attached device) higher than 100ohm/0.05%=200k? Would be nice if the absolute maximum ratings were included on the spec sheet

Meter impedance does not really matter, unless you start talking 50 ohms. Exact max value will depend upon the output value and state of the battery ESR.

[jippie]

@Dave: Are there any absolute maximum ratings (non-damaging limit) for the µCurrent Gold?

Meter impedance does not really matter, [...]

How about maximum input currents per range? I did see the 5A and 250mA fuse sub-discussion, but are those the absolute maximum before the input shunts are toasted? I will definitely put a label on mine stating these ratinmgs so I will always be aware of them.

Take Jeri's CastAR for example. She'll basically be making a loss (or break even if lucky) on that $1M she got. Same with many other KS campaigns.

Indeed I think it is really hard for young players ( ) to estimate real cost of a project end-to-end. Afraid of making the project too expensive and as a result making no profit with unforeseen cost. Forgetting about tools, taxes, or postage, consumables, ... If someone like Dave goes through all the effort of eg. making a µCurrent I am absolutely fine with making a bit of profit.

[EEVblog]

How about maximum input currents per range?

The thing is that unless you are using a constant current supply (rare for a DUT), the current is going to be limited when you change ranges. e.g. if your DUT is drawing say 1A on the mA range and you accidentally switch to the uA range, it's not like the same 1A is going to magically flow through your uA 10ohm shunt resistor. DUT's don't work like that.
If you really need to know, it's maybe:

10A on the mA range.
250mA on the uA range.
5mA on the nA range.

But those wouldn't be sustainable indefinitely.

[george graves]

The thing is that unless you are using a constant current supply (rare for a DUT), the current is going to be limited when you change ranges.

Could you explain that a little more please.  I don't quite get it.  Why would the µCurrent effect the current at all?  Isn't it suppose to be transparent?  My multimeter doesn't limit the current.  Clearly I'm missing something.

[jippie]

The thing is that unless you are using a constant current supply (rare for a DUT), the current is going to be limited when you change ranges.

Could you explain that a little more please.  I don't quite get it.  Why would the µCurrent effect the current at all?  Isn't it suppose to be transparent?  My multimeter doesn't limit the current.  Clearly I'm missing something.

The internal impedance varies per measurement range of the µCurrent. So if you change ranges, the current will be affected by the internal impedance.

[jippie]

Maybe a nice option for the Beryllium-Copper edition: An over-current indicator that lights when the output opamp hits the voltage rail.

[SeanB]

Series resistance, the supply will typically be under 5V, as any higher you will not be worried about burden voltage and will use a regular DMM. Under 5V you want low resistance, so any miss settings will only have 5V at best on them. Often less than 3V where you would use this unit.

[EEVblog]

Could you explain that a little more please.  I don't quite get it.  Why would the µCurrent effect the current at all?  Isn't it suppose to be transparent?  My multimeter doesn't limit the current. 

Of course your multimeter can limit the current in the exact same way the uCurrent can, but up to 100 times worse than the uCurrent!
Measure 100mA on your mulitmeter and then switch to the uA range and see what happens, your product will almost certainly stop working.
That's because your multimeter has different current shunt resistors based on the range, just like the uCurrent.