The Solar Power Expert Blog

Free Charge Controller Kit – Part 7 – Assembling the Current Monitor Circuitry

by Chris - October 2nd, 2012.
Filed under: Charge Controller.

This page will show the step-by-step instructions for assembling the circuitry associated with current monitoring. Current monitoring is controled by IC1 (on the schematic), with supporting hardware. The ability to monitor its own current draw is what allows the maximum power point tracking (MPPT) algorithm to adapt and adjust as the peak efficiency point changes.

  • Step 1
    Add IC1, the LT6101 current monitoring IC, to the protoboard. The IC footprint made for this type of IC, but the pins still align. This is will be the hardest part to solder to the board. Be careful and take your time. Tweezers help a lot!

  • Step 2
    Insert a jumper to connect the IN+ pin to the current sense resistor, RSENSE, as shown in the schematic.

  • Step 3
    Use a jumper to connect the other side of Rsense to Rin and then to the IN- pin of IC1.

    Schematic picture here

  • Step 4
    Add jumpers to connect Rin with the V+ pin (yellow wire) as well as the future location of C1 (red wire).

  • Step 5
    Add C1 as well as a jumper wire to connect its negative terminal to ground.

  • Step 6 (optional)
    This would be a good time to mark the jumper wires with a paint pen to clearly indicate which wires are connected to power and which to ground. In the pictures below, I use a white paint pen for power and a black paint pen for ground.

  • Step 7
    Solder on Rout, as well as the jumper wires to connect it to the analog input pin of the Arduino

At this point the current monitoring hardware is installed. Next, I’ll show how to test the current sensor with the oscilloscope as well as impliment the software to allow the Arduino to read it.

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