Epson DLQ-3000 Service Manual page 34

Operating Principles
sequence used to print a dot has been described above.
The
The mechanism is equipped with a built-in thermistor for head temperature detection. The
temperature detected by the thermistor is converted to an electric signal and fed back to the control
circuit.
As shown in Table 2-1, the energizing mode changes according to the paper thickness and head
temperature. This control is aimed at providing consistent print quality. The temperature
compensation is particularly necessary in order to minimize burning or degradation of the dot wire
driving coils inside the Printhead, which may result from excessive temperatures due to
continuous printing.
Table 2-1 lists the Printhead unit specifications for the
electrical specifications.
Printing Methcd
Number of wires
Wire diameter
Head life
Weight
Coil resistance
Response period
Driving voltage
Driving condition
Insulation resistance
Environment conditions
2-2
Table 2-1. Printhead Specifications
Impact Dot Printing
24 (12 x 2 lines, vertically) = number of driving coils
0.2 mm
200 million strokes /wire (monochrome fabric ribbon)
100 million strokes /wire (film ribbon, color ribbon)
Normal service: 462 @
31.5 to 38.5 VDC
Normal
Copy mode (when thick paper is used)
Warm mode (when the head temperature is high)
Cold mode (when the head temperature is below 120C)
500 VDC, 100 MQ or more
Temperature: 5 -55'C
Humidity: 10-857.
Refer to later section for the