Hi, I have an array of 12 HC-SR04 ultrasonic sensors, which are all connected to one Arduino Mega and are powered by a single 5V 40A external power supply. The Arduino is being powered through a laptop and is grounded to the power supply as well.
I'm currently encountering an issue where if the power supply is turned on and kept running, the ultrasonic sensors will give wrong and unstable readings, however when I switch the power supply off and its light slowly turns off (where the power supply starts discharging? I'm not sure about the correct term sorry) the sensors work as expected and are completely fine for that 5 seconds the power supply is turning off. I'm not very well-versed in electronics so any advice would be much appreciated to what this issue could be, thanks!