This week I set out to determine the issue related to our IR circuit and determine a solution to ensure proper functionality. Given that the PCF8575 expander board, which is powering the IR circuits, will only supply 200uA.
I determined that we will need a secondary 3.3V supply which will also supply up to 80.24mA. This number comes from the 4 IR Emitters which run best at approximately 20mA each and the 4 photodiodes which have a avalanche current of 60uA.
For this purpose we will resort back to a previous voltage regulator. The LD33V can supply early 10 times that current with a proper supply voltage and can be run off of the USB port of the PWM Charge Controller to Supply the voltage. The only thing that may need to be added is a control switch similar in nature to those used for the Thermistor circuits to provide electrical isolation.
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