Servo power requirements

I’m using mini Maestro, 18 servos/board and read a number of comments on this forum about the power requirements. Basically 1A/servo is what should be allowed.

Now I looked at this tiny board and really wonder how anything on it can handle even ONE amp, let alone the 3A peak that is mentioned elsewhere (I think that was “pin rating”).

How do you do it? Schematic available?

If you take a look at the Maestro boards, there are copper traces connecting the servo power terminals to the battery terminals. Are you concerned that the traces aren’t capable of handling the current?

no, just curious how it is done. Is the logic switching in the servo itself? My experience with driver chips like 74LS244 or ULN2003 is that a small pulse on an input drives common collector outputs to ground. The chip has to be able to carry that high current. On the mini-Maestro servo board there is no “big” current carrying chip, so I assume then that it is in the servo itself. Is that correct?

Standard hobby servos have logic circuitry and a motor driver built in. The signal line expects a pulse of variable width, which specifies the arm position.