The performance of a galvanometer scanner can be influenced by the DC power supplied to the servo amplifier, and the way it is connected. This type of servo amplifier typically requires the user to provide a positive and a negative voltage with a shared ground. Plus and minus voltages are needed to facilitate rotation of the scanner in a clockwise or counterclockwise direction.

The power consumed by the Scanners during vector movements is characterized by a short pulse of current at the beginning and end of each vector movement. These pulses last only a few hundred microseconds, but can reach peak values of several amperes for small mirrors and up to 8 amperes for larger mirrors. The power supply must be able to supply this instantaneous current and the wiring should be designed to provide a low inductance connection to the servo amplifier. In XY scanning systems the power supply must be able to satisfy the current demands of both axis under maximum load conditions. A solid ground connection between the X and Y amplifiers will minimize the possibility of crosstalk between the channels.

While linear power supplies are preferred in some applications for their low noise characteristics, most system designers prefer to use switching power supplies for reasons of cost, size and weight. Switching supplies are completely adequate in most applications, but it is best to choose a supply with a switching frequency above 100kHz so that any switching noise will be well above the control bandwidth of the servo. A plus/minus configuration can be realized by connecting two single voltage supplies in series. In this configuration it is important to make sure that the two supplies start up together.

There is some flexibility with respect to the supplied voltage. +/-15 volts is the typical minimum requirement. This provides enough voltage to the output stage for most applications and sufficient overhead voltage for on board regulators. Most designs will allow the supply voltage to be increased to 24 or 28 volts. In cases where the scanners performance is limited by saturation of the output stage, it makes sense to increase the supply voltage, however such cases are rare. Since increasing the supply voltage will cause additional heating of the voltage regulators and the output stage, it should only be done in cases where saturation has been shown to occur.