Filed under: Charge Controller.
This is the fourth part of a multipart series of articles describing how I constructed the v4 Free Charge Controller kit from Jameco. See Part 3 here, Part 2 here, and Part 1 here. If you have not done so yet, please complete those parts first.
When testing the charge controller, I strongly recommend that you use an adjustable voltage power supply that also has over-current protection, or a ‘current mode’. The YouTube video below explains how I use mine to protect the circuitry.
If you don’t have a power supply, you may be able to use a 12 volt battery and 1 amp fuse. Be sure to use a fuse to protect all your hard work!
Before connecting any power through, use a multimeter or ohm-meter to test the resistance at the input. It should read infinite or at least here high (above 1000 ohms).
If the resistance shows anything lower than 1000 ohms (1K Ohm), then most likely part of the hardware is configured wrong. Go back through the assembly steps in Part 3 and double check your work. Be very wary of resistance measurements lower than 10 ohms. You will blow something up if you connect power!
If you’ve gone over Part 3 and can’t figure out what’s wrong, try reaching out to the mailing list for help. Once a few people have built charge controllers, crowd-sourced assembly instructions should start appearing on the wiki.
Once you’ve verified that you can hook the power circuitry up to the power supply without any problems, insert the driver controller IC (IC2) into the socket. Measure the input resistance again before verifying for a second time that the controller circuitry is not drawing power.
Upload the driver_test.ino Arduino program to the Arduino. Disconnect power from the Arduino, and then connect the two boards. With the two boards mated together, the power draw should not change. It should be around 0.06 amps (60 mA).
If you have an oscilloscope, connect it to the Source pin of M1 or the Drain pin of M2. You should get a 100 Hz square wave that matches this oscilloscope image:
If your output does not match the oscilloscope, or if you run into problems elsewhere, try reaching out to the mailing list for help. Once a few people have built charge controllers, crowd-sourced assembly instructions should start appearing on the wiki.
Part 5 of this guide will cover the assembly instructions for the load circuitry containing the power inductor.