The SPM-D11 Series are microprocessor-based synchronizers designed for use on one- or three-phase AC generators equipped with Woodward or other compatible speed controls and automatic voltage regulators. The SPM-D11 Series synchronizers provide automatic frequency, phase, and voltage matching, using either analog or discrete output bias signals. It combines synchronizing for one circuit breaker, load and power factor control, or isochronous load sharing and generator protection.