XJ128 and XJ128 Plus Printhead
XJ128 Guide to Operation
Xaar Document no: D031010302 Version A
Page 30
It is recommended that a safety circuit be implemented into the power supply of the
printhead in case of abnormal power failure. The printhead does not contain any
current limitation devices, or the ability to shut down the power supply in the necessary
sequence.
Failure to operate the printhead with the recommended voltage and current values can result in poor
reliability and incorrect drop volume.
6.1.4 Temperature compensation
Temperature compensation within the XJ128 printhead is an internal printhead function. This
section is therefore for information only.
As the operational temperature of the printhead changes the viscosity of the ink in the printhead will
also change. This change in viscosity would influence the drop volume and performance of the
printhead if not compensated for. The XJ128 automatically changes the driver chip voltage to
compensate for the change in operating temperature.
The temperature compensation for the XJ128 is fixed and cannot be adjusted.
Lower temperatures give higher viscosity and therefore require a higher driver chip voltage.
Higher temperatures give lower viscosity and therefore require a lower driver chip voltage.
Figure 6.2 - Temperature compensation
‘
curve
’
example
Driver chip
voltage
Temperature
(deg C)
22 C
23 Volt