Dc-To-Dc Converter Power Supply for Display Terminal Cable Isolation
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-07
The shield on a display terminal coax cable must be isolated from ground in order to prevent ground loops. Optocouplers can be used to isolate the coax cable, driver and receiver from the rest of the grounded electronics. Power for the optocouplers, cable driver and cable receiver is conventionally supplied from a separate floating line voltage supply. However, when this cable attachment is made to equipment which does not have such a supply, or to reduce the cost of a power supply, a separate DC-to-DC converter can be used to provide the power isolation. The converter, as seen in the figure, derives its input power from an already existing supply voltage.