This page will outline my validation and results and troubleshooting for the power select board.
The first test is kinda a smoke test ->I will have 5V initially on the Aux input from a power supply, and the eload connected to the output in CC mode currently drawing 500mA (to start off) → I will then increase the input voltage to see when the output is connected
I may have figured out a logical flaw → for the LTC4417 to be enabled, there must be a 3V3 output from the controller board. However a standalone controller board needs 12V input to have the 3V3 reference, except that 12V in the schematics seems to come from the output of power select, which only has a 12V reference when the LTC is enabled. Therefore, it should never enable standalone
I connected the controllerboard to my laptop for the 3V3 reference, and started the power supply at 5v, with the eload showing that it has around 70mV. I increased it in 1V increments until it reached 10V output, in which the eload suddenly changed to 9.998Voc, meaning the LTC was regulating the supply! Note that at this point, I took out programmer from my laptop, and I still see the 3V3 rail which further verifies my assumption is probably right. see the following table for some points
Voltage input (Aux) (V) | Current on Eload (A) | Voltage on output (V) | other notes |
|---|---|---|---|
10.01 | 0.5 | 9.94 | before this point (1V increments) no output, and I had to connect the programmer again to enable the LTC4417 again |