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I have a mini project I'm supposed to be doing for university. I've decided to build a charge controller. We aren't allowed to use micro-controllers, so I'm grateful I could find exactly what I need. The problem is I have no experience understanding circuits this complex. I was hoping someone could explain it to me and also provide me with resources to learn how to understand circuits like this.

The link to the blog where I got this circuit -> https://microcontrollerslab.com/15-ampere-solar-charge-controller-without-microcontroller/

Also, I'm using Proteus, and I'm having trouble finding the solar panel component used in the circuit. Any help with that would be great.

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    \$\begingroup\$ One of the things to consider with a charge controller is, obviously, the battery to charge: voltage/current vs. life expectancy & hazards, temperature vs. voltage. \$\endgroup\$
    – greybeard
    Commented Nov 27, 2023 at 13:19

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That's a very basic charge circuit. Better ones use maximum power point tracking. The article itself gives a description of how it works. Essentially, all it's doing is monitoring the battery voltage, and if that voltage is too low it switches on the MOSFET to connect the panel to the battery.

The article says that the panel is a 200W one with 24V open circuit and 18V on load. That should be enough to find a suitable panel. The exact specification won't be critical anyway.

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    \$\begingroup\$ There isn't even any hysteresis on the comparator, so as soon as the panel is switched on and the battery bus voltage rises a bit, it will immediately switch off again. It basically functions as a voltage limiter for the battery, but isn't otherwise "controlling" the charging process at all. \$\endgroup\$
    – Dave Tweed
    Commented Nov 27, 2023 at 13:29
  • \$\begingroup\$ I get the general Idea. But there are so many resistors, capacitors and diodes. I don't know why they are placed there and in that structure. Is there a resource you could recommend that would make it make sense \$\endgroup\$
    – Olalekan Adekanmbi
    Commented Nov 27, 2023 at 14:05
  • \$\begingroup\$ @OlalekanAdekanmbi a good degree course in electronics would help. Remember that all well-drawn circuit diagrams read left-to-right. I look at it and see: two voltage dividers, a 5.1V reference voltage, a comparator (it looks like an opamp, but with no feedback, it must be a comparator), an unused spare comparator, an NPN transistor with a base current limiting resistor and a decoupling capacitor, and a MOSFET being switched on and off by the NPN transistor. Then there's an LED to tell you it's on and a diode to prevent the battery back-feeding the charger when the charger is off. \$\endgroup\$
    – Simon B
    Commented Nov 28, 2023 at 14:50

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