Onboard equipment such as single side-band radios, radar rectifiers, halogen and other lighting systems require a constant DC voltage to operate, yet the source does not have to be batteries. Power supplies may be used to run this equipment. They provide a constant 14.4 volts DC and are lightweight, compact, clean, quiet and easy to install. They are able to accept variances in frequency, 45 to 65 Hz, and variances in AC input (120 VAC units: 90 to 135 VAC, 220 VAC units: 180 to 270 VAC) without degrading output.