Yeahbut.. it's more fun when you and Forrest make something we want
and/or didn't even know we needed and we can say.. shut up and take my
money.
On 6/16/2017 1:33 PM, ch...@wbmfg.com wrote:
Never mind. This one need to be installed in the circuit. Not sure
of the advantage other than isolation.
*From:* ch...@wbmfg.com
*Sent:* Friday, June 16, 2017 12:32 PM
*To:* af@afmug.com
*Subject:* Re: [AFMUG] PacketFlux shunts
https://www.sparkfun.com/products/8882
*From:* Bill Prince
*Sent:* Friday, June 16, 2017 12:08 PM
*To:* af@afmug.com
*Subject:* Re: [AFMUG] PacketFlux shunts
A Hall effect sensor would be the gold standard for a non-intrusive
way to sense current. I looked at cobbling together something on my
own, but it was more complicated than I anticipated.
bp
<part15sbs{at}gmail{dot}com>
On 6/16/2017 11:01 AM, George Skorup wrote:
All we've ever bought are the 10A version. They read accurate enough
to see when a 1/2 or 1A DC-UPS is charging as well as 3-7A the other
direction when the load is running on battery. Typical 24 and 48VDC
systems with <200W load. And then me not paying attention with the
Traco BCMU's 12VDC. Using the 2-relay/3-switch module, remotely I
could see that the "Batt OK" contact was open after power came back
up at the site at like 4am and still open around 8am. Since the site
went down sooner than expected, I figured either the battery fuse on
the BCM blew or it was sensing some other issue. So I get there and
put my clamp-on ammeter on it and zero current. Two fused 20AH
batteries in parallel both sitting at 13.1 volts. OK, WTF. Then it
all made sense with the shunt.
Another thought I had is... what about Hall effect sensors? Could you
do a module for that? That would be pretty cool.
On 6/16/2017 11:00 AM, Forrest Christian (List Account) wrote:
There will likely be a 20A shunt in our future. I'm in the
process of redesigning these so that they're less expensive to build
since the existing design is being sold at or possibly below cost.
I'm trying to end up with a 20A shunt as a result but I don't know
for sure if this will happen.
On Jun 15, 2017 5:47 PM, "George Skorup" <george.sko...@cbcast.com>
wrote:
Forrest,
Would you be willing to make a 20A shunt? Would the traces on
your current design handle it?
Reason I'm asking is... I'm stupid. I had a 10A shunt on the
batt negative side of a Traco BCMU360. Didn't occur to me that
230 watts @ ~12VDC can get up to 20A. So the shunt went kaput
after about 25 minutes and the site went down. Not a problem at
most other sites with less load. This one happens to be the most
heavily loaded with two Trango ApexPlus, various APs and PTPs
plus the DC-DC inefficiencies.
