[TriEmbed] Measure uA

[John Wettroth]

You got it- 
 
Regards,
John M. Wettroth
(984) 329-5420 (home)
(919) 349-9875 (cell) 
From: The MacDougals <paulmacd at acm.org> 
Sent: Thursday, August 26, 2021 9:25 AM
To: jwet at mindspring.com
Subject: RE: [TriEmbed] Measure uA
 
I assume you mean using a 330 ohm as a shunt resistor in series with the load (not across the load).
Measure the voltage between the R and the load and use Ohm’s law to calculate the resistance of the load and then calculate amps.
 
---> Paul
 
 
From: John Wettroth <jwet at mindspring.com <mailto:jwet at mindspring.com> > 
Sent: Wednesday, August 25, 2021 6:16 PM
To: paulmacd at acm.org <mailto:paulmacd at acm.org> 
Cc: TriEmbed <triembed at triembed.org <mailto:triembed at triembed.org> >
Subject: RE: [TriEmbed] Measure uA
 
This might sound barbaric but here’s a really good way for about 1 cent.  Use a 330 ohm resistor and a DVM that can resolve 10 millivolts- any good Fluke will do this.  You’ll drop your load across the R and do a little ohms law and voila.  If it’s a sleep current and the unit can draw big currents too, put a little switch across the resistor and don’t open the switch until you’re in sleep.  It’s a nice old trick that I’ve used for years.
 
Regards,
John M. Wettroth
(984) 329-5420 (home)
(919) 349-9875 (cell) 
From: TriEmbed <triembed-bounces at triembed.org <mailto:triembed-bounces at triembed.org> > On Behalf Of The MacDougals via TriEmbed
Sent: Wednesday, August 25, 2021 4:55 PM
To: triembed at triembed.org <mailto:triembed at triembed.org> 
Subject: [TriEmbed] Measure uA
 
I want to measure DC current of ESP8266 while in deep sleep.
Should be around 19uA.
 
I recall Dave Jones had a device that turned a volt meter into an amp meter.
https://www.eevblog.com/product/ucurrentgold/
 
I found this clone:
https://github.com/nfhw/tinycurrent
 
Looks like it is available assembled from Germany for 60.50 €
https://www.n-fuse.co/devices/tinyCurrent-precision-low-Current-Measurement-Shunt-and-Amplifier-Devicehtml <https://www.n-fuse.co/devices/tinyCurrent-precision-low-Current-Measurement-Shunt-and-Amplifier-Device.html> 
 
Anyone already have one of these?  Anyone else interested in getting or building one?
Other options/ideas?
 
---> Paul
 
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