Olivetti JP 90, Руководство по обслуживанию

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Information on the Heating Element's Activation Circuitry
The heating elements are divided into four groups. Two groups have 12 elements, the other two groups
have 13. Only one element can be activated at each time in each group, and therefore no more than four
elements can be activated simultaneously.
To avoid induction between adjcent elements, each element will be activated according to a specific
sequence (Fig. 1-6).
Each group of heating elements is controlled by an 18.8 V driver circuit. This voltage must be regulated
in order to guarantee correct print head operation.
The most typical faults that can occur with lower voltages are the following: lack of ink bubble expulsion
if the print head is not used for a determined period of time, lack of ink bubble expulsion in low temperatures.
Higher voltages, on the other hand, can cause the generation of incorrect ink bubble control commands or
no command at all due to the possible deterioration of the heating element.
.
Cleaning and Servicing the Ink-Jet Print Head
The ink-jet print head demands special care as far as nozzle cleaning is concerned.
Given their particular structure, dust or the drying-out of exposed ink can easily clog the nozzles.
Fig.1-6 Activation Sequence of the Heating Elements
HEATING ELEMENT ACTIVATION
COMMAND