Hello. I’m an amateur at electronics/ robotics/ software/ etc. and I could really use some help understanding how to safely power Maestro servo controllers and servo motors.
I own a Micro Maestro 6-channel servo controller, and I was powering three Hi-Tec HS-485HB servo motors with 5vdc supplied from a voltage regulator to the GND and PWR pins on the board. The motors worked well, but I wanted to experiment with an old external AC adaptor by powering one of the three servos with 6vdc instead of 5vdc (I know 6vdc is safe to use with these servos). I pulled out the GND and PWR wires from the board and hooked them up to the output voltage coming from the AC adaptor. I kept the signal wire the way it was. After trying to test it, I noticed there was some smoke in the air. The AC adaptor fried my servo! I quickly removed power to the servo. I tried reconnecting it back to the Maestro, but the servo was so far gone that it created a short in the voltage regulator powering the other servos. The bad servo now has that burnt electrical smell. I tested the AC adapter with two separate multimeters and found that it was putting out nearly 10 volts! I believe this extra voltage is what killed my servo. The AC adaptor has gone bad, and is not putting out the correct amount of voltage now.
Why did this older AC adaptor go bad? Could this happen to my other older AC adaptors if I consider using them? Do you have any advice on what the safest way to power servo motors and/or Maestro controllers is?
Thank you for your time.