OpenEnergyMonitor Community

Shunt Monitor Breakout Board

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Hello, I’ve put out for a quote for a shunt monitor breakout board based on the LMP8481.

I’ve tried making in flexible in a number of ways.
-The LMP848x chip is powered either from the DC source or from 5VDC by usb or headers. The chip is rated at 85V
-The refA+B inputs can be accessed for bidirectional monitoring with a chosen ref voltage. (refA+refB) / 2 must be less than 6V.
-Pads for shunt, mounting holes, and 3.5mm screw terminals for different options on input. Pads are compatible with all EBW series manganin shunts, plus many more I’m sure.
-Various jumper locations for access.

I’ll have a few basic filtering capacitors SMC soldered to the board with the chip. I was going to hand-solder any Vdiv resistors, shunts, screw terminals (3.5mm pitch), and other connectors and jumpers as I need.

I’ve got to get busy finding my next £££ job in construction, my usual thing, so I hope this little breakout is useful.

Any feedback welcome. There are a number of places where DC pins are in proximity to GND pins. I think the best I can do is warn of the dangers when it comes to DC shunt monitors, especially if connected to a source that can deliver huge current, Lion battery packs, solar arrays, turbines… many things really.


Updated board done.
Now breadboard compatible.
The source/load to GND possibilities have been reduced.

Hi @danbates

Project looks interesting, is this purely for DC current measurement - what current limits do you expect?

Yes, DC only.
With an external current shunt
sky’s the limit.

With an on-board shunt, hard to say. Fiddling with my calculator I work out about 30A based on 0.5W dissipation.
Bit of a balancing act of different factors effecting accuracy, keeping Vout high and heat generation low.

There’s a jumper pin free on the board for a temperature sensor, so something clever could be done like temperature adjusted readings.