BIXOLON SMP6200II, User Manual, Page: 28 / 70

Rev. 1.00
- 28 -
SMP6200II
※
Recommended Thermistor circuit
User side
TH
V
DD
Ground
10㏀/F
100㎋
25
TH
26
Printer side
GND
TPH Thermistor
10㏀/F
3㏀/F
LM393
+
-
10㏀
H_TMP
100㎋
5-10-5 Detection of abnormal temperature of thermal head
In order to protect the thermal head and to guarantee the safety of the user, abnormal
temperature of the thermal head must be detected from both hardware and software sides.
▷
Detection of abnormal temperature with software
When the software detects a temperature higher than 60 C from the thermistor of
the thermal head, the software must stop the operation of the heating element, and
reactivate the heating element when the temperature drops below 50
°
C.
Continuous operation of thermal head at a temperature above 60°C may reduce the
life of thermal head significantly.
▷
Detection of abnormal temperature through hardware
The thermal head might overheat if the software to detect abnormal temperature
does not operate properly if there are problems in the control system. Overheated
thermal head may result in damage to the thermal head and injury to the user.
Hardware circuits to detect abnormal temperature must be used along with the
software to detect abnormal temperature to guarantee the safety of the user. (The
damage to the thermal head may not be avoided even when the hardware detects
an abnormal temperature if there is a problem in the control system.)
Design the hardware to detect the following abnormal conditions using comparators
or other similar sensors.
1) Overheating of the thermal head (Around 90
°
C or higher)
2) Improper connection of thermistor (Thermistor might be shorted or opened.)
Cut the supply voltage to the thermal head if condition (1) or (2) is detected.
Activate the error mode for proper measure before reusing the system.