This paper presents the design and construction of a regulated, multiple output DC power supply based on the principle of pulse width modulation. DC power supplies based on this principle are called switch mode power supplies and have become the dominant architecture for DC power supplies, due to their capability to handle variable loads, high efficiency, relatively small size, and weight. Switch mode power supplies have many different topologies. This paper presents the design of a 150W, single switch forward converter with three output DC power supply, and simulated using MULTISM 10.0. The device performed satisfactorily during tests.