Abstract: A plurality of AC synchronous motors used to drive respective machines in a manufacturing or packaging assembly line or system are driven in speed and phase synchronization. A common AC current supply signal is inverted to provide one polyphase set of series of controlled frequency low voltage DC pulses in a lead inverter. This polyphase set of pulses are amplified and utilized to drive the AC synchronous motor for the lead machine in the system. This same set of polyphase pulses are also transmitted directly to follower inverters respectively and there amplified to drive respective synchronous motors in the system to not only insure speed synchronization but also absolute phase synchronization in driving all machines in the line. When the frequency of the polyphase set of pulses is varied to correspondingly drive the AC synchronous motors at predetermined speeds, phase synchronization of the motors will always be insured.