How to Make a 60Hz DC Source

Change the voltage of the input to the output voltage you want before doing anything else. The single device that can do this is called a transformer. It consists of two coils of wire. The input coil is called the primary coil; the output coil is called the secondary coil. The AC input to the primary coil causes a rising and falling magnetic field that induces an AC current in the secondary coil -- an image of the input AC. The ratio of the number of windings of the primary and secondary determines the ratio of the input and output voltages. If the secondary has half the windings as the primary, the transformer cuts the voltage in half.

Use a diode to lop off half of the input AC. Diodes are made up of two different semiconductors -- crystal-like substances that have either free electrons floating around -- or "holes" -- places where an electron should be -- floating around. When a positive and negative potential is applied in one direction, the electrons and holes are pushed into each other, which causes current to flow. When the positive and negative are applied in the opposite direction, the electrons and holes are pulled apart and no current flows. Diodes allow current to flow in one direction but not in the other direction. When AC comes to a diode, either the positive surges or the negative surges are eliminated, depending on which direction the diode is installed.

Filter the output, which means making it smoother. A coil and capacitor working together smooth out the surges. The coil is in series, and the capacitor is across the output and just before the coil. The coil resists changes in the current level, and this resistance causes electrons to pile up on the capacitor. When the surge levels out, the opposition from the coil decreases and the electrons stored on the capacitor come back into play. The coil and capacitor work together to subdue the surges and fill in the "valleys" -- smoothing out the signal.