The Solar Power Expert Blog

Free Charge Controller Kit – Part 3 – Assembling the Power Circuitry

by Chris - September 29th, 2012.
Filed under: Charge Controller.

This is the third part of a multipart series of articles describing how I constructed the v4 Free Charge Controller kit from Jameco. See Part 2 here, and part 1 here. If you have not done so yet, please complete those two parts first.

You will probably want to have a paper copy of the charge controller schematic handy. Each step illustrates the area of interest in the schematic with a red box.

  • Step 1
    If you have not done so yet, install the power terminals and the current sense resistor as described in the preparation steps in Part 2 of the assembly.

  • Step 2
    After jumpering power to the prototyping area, install the MOSFETs as shown in the images below.

  • Step 3
    Next, install the IC socket which will house IC2, the MOSFET driver IC.

  • Step 4
    Install the electrlytic input capacitor, C4. At this point, you can also perform step 13 and install the ceramic capacitor C10. I forgot to install C10 at this point. You can also continue on with the rest of the steps and install it in step 13.

  • Step 5
    Install a jumper to connecto the current sense resistor, Rsense, with the Source pin of MOSFET M1.

  • Step 6
    Install a jumper from the Drain pin of M1 to the Drain pin of M2.

  • Step 7
    Install a jumper from the Source pin of M2 to the Drain pin of M3.

  • Step 8
    Install the 470K resistor, R1, between the Source and Gate pins of M1. Next, install diode D1 between the gates of M2 and M1. Note the polarity on D1. The pin on the diode with the white stripe is the one that should connect to the Gate pin of M1.

    As you can see in the picture below, I had to bend the lead ont he diode over the jumper wire installed in Step 6 in order to reach the Gate pin of M2.

  • Step 9
    Install resistor R9 between the gate of M2 and pin 7 of IC2. Like the diode in the step before, I had to bend the lead over two jumpers. It should lay right on top of the lead from the diode, which makes it easy to solder. Be carefull when soldering, to make sure the heat does not melt the insulation on the jumper wires.

  • Step 10
    Solder resistor R10 between the Gate pin of M3 and pin 5 of IC2.

  • Step 11
    Install the electrolytic capacitor C3 and ceramic capacitor C11 as physically close to IC2 as possible. Note the polarity on C11. The white stripe indicates the negative, or ground, side. C11 is not polarized.

    At this point you can connect the positive sides of the capacitors to pin 1 of IC2. You’ll install a jumper later to connect the negative sides to ground.

  • Step 12
    Solder on the diode, D2, between pins 1 and 8 of IC2. Then install ceramic capacitor C2 between pins 8 and 6 of IC2.

  • Step 13
    Insert 100 ohm resistor R7 between pin 9 of the Arduino protoboard and pin 2 of IC2. Next, insert resistor R8, also 100 ohms, between pin 8 of the Arduino protoboard and pin 3 of IC2. Pin 9 is the PWM output of the Arduino, and Pin 8 will be used as an enable line.

  • Step 14
    If you didn’t do so in step 4, solder in the ceramic capacitor C10 to the power input.

  • Step 15
    Add a jumper wire to connect the grounds between the input and output of the charge controller.

  • Step 16
    Add a jumper wire to connect Pin 4 of IC2 to the ground pins of C11 and C3.

  • Step 17
    Add jumper wires (two) to connect the ground of IC2 and Source pin of M3 with the grounds at the input and output of the charge controller.

  • Step 18 (optional)
    Use a black paint pen to mark the jumper wires that connect the grounds of the charge controller.

  • Step 19
    Solder a jumper wire to connect pin 1 of IC2 to the output of the current sense resistor Rsense.

Now that the power circuitry is assembled, you’re ready to begin testing it. In Part 4, I have a series of YouTube videos that should help you debug the kit.

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