The solar powered LED lighting system I designed for my home has a battery bank with (7) 84AH 12V sunextender batteries bussed together. When I did a topic on the system a while back I was advised by one of the very capable eevbloggers to fuse each battery individually. I took that advice and fused each battery with an ANL fuse. I decided to design a current monitor to fit in each ANL fuse holder. The current monitor uses a +/-50A bidirectional hall effect curent sensor made by Allegro and is fused with an ATO blade style fuse. I want a +/-15A current monitor so the ATO fuse is 15A and I’m using an interface circuit to scale the sensor output to 0v to 5v for a sensor output of 1.9v(-15A) to 3.1v(+15A) and then scaling again in software to display to the nearest 0.1A (-15.1A to +15.1A). The PCB measures 0.875" x 3.25" and has large wirepads spaced and sized to allow the PCB to mount on the ANL fuse holder threaded posts. One concern I had while designing the PCB was the current handling ability of the 2oz copper traces. Trace current calculators indicated I would be OK to 15A but I was still concerned. I’ve now tested the board to 14.8A and if the traces were warm it was hard to tell (approx 25C ambient). For testing, I have the interface circuit on a breadboard and I’m inputting the scaled sensor voltage into MS2 (PIC pin reconfigured as analog) on the master PDAC controller in my lighting system. It then goes via the lighting system network to a floating point LED display. Details of the network and display can be found at these topics;
https://www.eevblog.com/forum/microcontrollers/a-full-duplex-network/https://www.eevblog.com/forum/microcontrollers/networked-rtc-fp-display/Attached are the following files;
Current Monitor Schematic and PCB as pdf
Interface Circuit Schematic as pdf
PDAC schematic for reference as pdf
Display Scaling Flowchart as pdf
Current Monitor Testing Photographs
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