Thinking through a design that interfaces a solar panel to a 12V diaphragm pump, and considering the interfacing options. I've come across the term "Linear Current Booster", and wanted to explore this idea further.
While the concept of "MPPT" controllers is fairly well documented for solar panel to battery systems (and ICs are marketed for this purpose, like the fairly fancy Linear LT8490), I'm not seeing as much documentation around the Linear Current Booster.
I understand the concept of a Linear Current Booster as a DC-DC converter that:
- Reduces a solar panel voltage to a lower output voltage, and increases output current,
- Ensures that the minimum output voltage is above some threshold (how does it determine this?) to ensure that the pump does not run at 0V; which would be effectively running at 0 RPM and burn out the windings in time,
- Ensures that the maximum output voltage is limited, to ensure that the pump does not overspeed.
The advantage (as I understand it) is to be able to operate in lower light conditions; when the panel could not provide enough current to the pump to give it enough torque to start moving if it was directly connected.
Some examples of commercially available Linear Current Boosters:
So, does anyone here have any insights on the difference between a DC-DC buck converter and an LCB? I think that all of the functions of an LCB can be accomplished with a buck converter that implements an output undervoltage/overvoltage lockout. Is my understanding correct?
EDIT - It looks like the author of this buck converter design indicates that "Another application for this circuit is as a "linear current booster" (LCB). Common LCB uses include running motors and other devices directly from a solar panel with no battery. In the LCB mode of operation, it is possible to use the circuit to change a low current solar panel input to a higher current (but lower voltage) output."