The sketch rotates servo back and forth with buttons. When I rotate servo MG 995/996R 2-4 times Arduino stops working. Its voltage step-down transformer drops from ~9V to ~3.7V which is not enough for Arduino.
To make it work again, I must turn off-on the device.
There is no such a glitch with smaller servos such as SG90.
What I do wrong?
And how even servo able to affect Arduino’s power supply?
Please provide more details about the 12V supply and the two DC-DC converters shown in your picture.
Without any useful details I can only guess that the 12V supply cannot provide enough power for the larger servo(s) and that is failing, bringing the 9V to the Arduino down with it causing a reset.
Steve
No transformers here, just buck converters, different thing.
Anyway yes, you are likely overloading your 12V supply and it current-limits, bring down the voltage.
People consistently underestimate the power requirements of servos and motors - they use lots of current, make sure the supply is generously rated, at least 50% more than the peak current load is a good guideline.
