There are many applications which require phase angle adjustment between voltage and current, voltage and voltage, and current and current. One example is electricity meter testing, in which the voltage and current are tested in phase and also out of phase. Another example is 3-phase (3-pole) circuit breaker testing, in which the phase angle among the poles should be 120 degrees apart. The ALC 3-phase and 6-phase digital oscillators are designed for industrial tests with accurate phase angle adjustment requirement. The phase angle among the output channels is 0.0o - 360.0 o adjustable by either RS232 or GPIB commands. Besides the phase angle, the output amplitude, output frequency, output On/Off are all controllable by RS232 or GPIB commands, too. These multi-phase oscillators are equipped with External Synchronization and Closed-loop Feedback functions also. The 3-phase and 6-phase oscillators will automatically cover the 2-phase, 4-phase, and 5-phase applications. They are widely used in industrial testing and military manufacturing environments.