Ribbon drive system for a thermal demand printer

A printer of the type used for printing on tickets, tags, pressure sensitive labels and other media, said printer having various components and comprising:

• a case structure for housing and supporting said components including walls defining a base cavity;
• a power supply circuit for receiving power from an external source and conditioning said power for the operation of said printer, said power supply circuit being disposed in said base cavity;
• input means for receiving command signals related to the operation of said printer;
• control circuit means mounted on said structure and coupled to said input means and said power supply circuit for processing said command signals and generating corresponding control signals for controlling the operation of said printer;
• printhead means for receiving said control signals from said control circuit means and printing indicia onto said media;
• media delivery means operatively associated with said printhead means and coupled to said control circuit means for moving said media to said printhead means in response to said control signals;
• a switch circuit line coupled to at least a first and a second point on said power supply circuit, said switch circuit line providing a first operating voltage for the operation of said printer when connected between said first and second points in said power supply circuit, said switch circuit line providing a second operating voltage when the connection between said first and second points is opened;
• and
• means for severing said switch circuit line operatively associated with said case structure, said severing means projecting into said base cavity and being retained therein for maintaining an open circuit between said first and second points on said power supply circuit once said switch circuit line is severed.