+1 I'd like good accuracy, but it's not that important.
I have had surge suppressors fail in a way where they still work but the
power consumption nearly doubled. If I can get any indication of this
from my couch, it's a helpful feature. Also, I can look at a number of
SyncInjectors and see some kind of current reading. OK, so that port is
showing some current, but the ethernet link is down. Look at the graph
for that port. OK, looks normal, so I know the radio is powered up. Oh
great, the ethernet is dead. Replace in the morning. Both of these cases
don't need highly accurate readings.
Times when I might want high accuracy.. say the master/input on the 5ch
PDU or the SyncInjector. Or take some new kind of -48 injector or PDU.
Say I have a Trango licensed radio. I know that it will be pulling about
75 watts when the ODU is on and transmitting. If it's pulling about half
of that, then the ODU is not on or will not start up.
Just my $0.02.
On 9/23/2015 8:35 PM, Mark Radabaugh wrote:
It’s kind of convenient to be able to check current but I don’t need
it to be particularly accurate
Mark
On Sep 23, 2015, at 8:10 PM, Forrest Christian (List Account)
<[email protected] <mailto:[email protected]>> wrote:
So, I think I've about got the design for the next iteration of
injectors nailed down, with one exception.
I'm not quite sure what to do about overcurrent protection.
Let me ask this question up front:
How important is it to be able to read the current being drawn by
each radio?
In the current SyncInjectors, Airfiber injectors, and 5 channel
PDU's, I do active overcurrent protection. In short, the
microcontroller measures the current through each channel using a
hall effect sensor and when it detects an overcurrent it just shuts
off the port.
The advantage of this is that we get very rough current measurements
(like you can usually tell if a radio is on or off, or drawing more
power than normal, but NOT anything close to an exact measurement),
and I can somewhat adjust the response to the overcurrent to handle
inrush and the like. This is also fairly expensive per port (like
they add around $5 per injection port to the cost of the product).
With the altered design I'm looking at the current measurement
accuracy would go up for around the same cost.
On the other hand, In the past I've just used self-resetting (aka
PTC) fuses, which are simple and very robust, but don't end up with
current reading as a side effect since the microcontroller doesn't
get involved. I can definitely detect a overcurrent (aka fuse has
been tripped) easily and expensively, but can't tell how much current
is actually being drawn.
My decision is coming down to a perceived value choice. Is it worth
$5/port on an injector to be able to read the actual current used?
--
*Forrest Christian* /CEO//, PacketFlux Technologies, Inc./
Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602
[email protected] <mailto:[email protected]> |
http://www.packetflux.com <http://www.packetflux.com/>
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