Fusing System Electronics

The controlling electronics for the fusing system can be divided into two areas: 1) control of input line voltage and 2) temperature control of the preheater. The fusing system has been designed to operate at 216 volts rms. This is the lowest voltage at which the 26h0a will operate.

The line voltage to the fusing system is monitored by the machine control system (MCSJ. To maintain nearly constant fuser power, half cycles of the ac line voltage are clipped. For example, at a line vollage of 250 volts one out of every four half cycles is clipped out of the ac input voltage. As I he line voltage changes, the fraction of clipped half cycles changes, as shown in Fig. 3.

The temperature of the preheater surface is measured by-small thermocouples attached to the back side of the ¡ire-heater plate. The silicone rubber foil heater is divided into three sections which are controlled separately. A thermocouple in the center of each section provides a feedback signal to a proportional controller. The thermocouple signal is also used by the microprocessor to monitor the operation of the preheater. If for some reason a failure occurs and the temperature of the preheater exceeds a preset temperature, the line voltage is removed from the fusing system. If a paper jam occurs, the fusing system is shut down immediately.

interests include tennis, snow and water skiing tinkering around his home in Boise. Idaho

Roger D, Archibald

With HP since 1975, Roger Archibald was pan of the 2680A project team and now is a project manager for nonimpact printers He was born In Biacktool. Idaho and attended Bngham Young University earning ihe BS (1974) and MS (1975) degrees in mechanical engineering Roger also holds an MBA degree from Boise State University awarded In 1979 He is a registered professional engineer in the State of Idaho Roger is married and has two small children. Besides holding various positions in his church and the ■Jt Boy Scouts of America, his ouiside woodworking, and

0 0

Post a comment