Alternating current (AC) power supply can be classified into single-phase and three-phase sources. Knowing the difference can help us determine when and where to use which. Requirements in airborne and ground applications utilizing AC sources of supply are becoming more frequent. In some cases, the traditional 28VDC direct current (DC) bus is at maximum current capacity and is not available, especially for higher power applications. The AC bus is often readily available for use and makes sense for upgrade and modernization programs to enhance capability on a platform.
Fixed, single-phase alternating current, without a change in frequency, delivers voltage in a complete cycle of 360 degrees, which means that the power generated in this single-phase manner is not constant. As voltage peaks and dips throughout its cycle, power delivery varies between the desired maximum and none at all. It is best used and more efficient when electricity requirements are low, often in homes and while running small equipment. An example of the use of single-phase AC power in a military application may be a sensor upgrade drawing relatively low power from the system. With the right power supply, this upgrade can be quickly and efficiently integrated into the platform. AC distributed throughout a tactical operations center from a wheeled vehicle is another example where single-phase 120V AC power may be used as a source of supply.
Three-phase power carries a heavier load and can be used for running larger machinery in factories by creating a more consistent supply of power. It creates a safe environment for high-demand applications where security and stability are essential. Three-phase works by creating a constant current with stages of alternating signal separated by 120 electrical degrees. The combination ensures that the maximum power delivery to the load is constant. High current demand for heavy processing or motion control in a military platform is an excellent example when an engineer chooses to use three-phase AC power as a source for the subsystem.
Our products support shipboard, military shelters, tactical, mobile, ground support, and communications applications. M2701, M2781, M495 and M167, our three-phase power supplies, can be ruggedized for military-grade shock, vibration, temperature and humidity and designed to meet demanding MIL-STD-461 and MIL-STD-810. Our team understands the unique applications requiring single or three-phase AC sources of power and we offer a wide range of off-the-shelf designs that can be quickly tailored to meet your requirements. Whether you are facing a naval MIL-STD-1399 requirement, or require three-phase power off a ground vehicle alternator, we've got your solution.