The DC-DC Converter provides clean 24VDC power suitable for instrumentation and control networks or process equipment. For operation under the most harsh and demanding conditions, the unit is fully sealed and enclosed to protect against moisture, shock and vibration. Power from a battery or other source as 12 or 24VDC nominal is converted to a 24VDC output. The units are designed with extremely rugged surge and transient suppression in addition to sustained over/under voltage protection.