Ribbon Motor Temperature Sensor - Citizen CL-S6621 Technical Manual

(6) Ribbon motor temperature sensor

The ribbon motor temperature sensor is used to detect the temperature of the "SA Ribbon
Motor F" on the front side. This sensor is a thermistor bonded to the "SA Ribbon Motor F".
Since the resistance of the thermistor changes according to a temperature change, the voltage
at pin 11 (RBTMP) of U1A (CPU) changes accordingly. The CPU senses the voltage at pin 11
to detect the temperature of the "SA Ribbon Motor F".
U1A
CPU
RBTMP
ANI6
11
U14
FPGA
nTEMP_ENABLE
B2_28
C11
nTEMP_ERROR
B2_27
C6
Printing operation at ribbon motor temperature rise:
When the temperature of the "SA Ribbon Motor F" reaches 85 ° C (185 ° F), the "SA Ribbon
Motor F" stops after printing the current label. In this case, the PRINT LED and CONDITION
LED alternately blink on the operation panel.
When the temperature of the "SA Ribbon Motor F" falls below 80 ° C (176 ° F), the LEDs stop
blink and printing resumes.
Normal speed
Normal speed
For further safety, an abnormally high temperature detection circuit is provided. In case this
circuit is activated, the System error is displayed, and the printer stops.
The comparator U17A detects if the level at pin 3 (RBTMP) (i.e., the temperature of the "SA
Ribbon Motor F") exceeds a certain reference level determined by the output from pin C11
(nTEMP_ENABLE) of U14 (FPGA) (i.e., the predetermined allowable limit temperature). If it
does, nTEMP_ERROR at pin C6 goes "Low" level and this signal is fed to U14 (FPGA). Then,
the System error is displayed and the printer stops. At this time, nTEMP_ENABLE at pin C11 is
set to "Low" level so that nTEMP_ERROR is securely maintained at "Low" level. (To clear the
System error, you need to turn OFF the printer once and then turn it ON.)
C172
TEMP ERROR Detection
+3.3V
RBTMP
R40
R41
R42
C41
Error: Low
80 ° C
(176 ° F)
+3.3V
J19
R134
R135
17
18
+3.3V
R39
U17A
3
+
1
2
-
BA2903SFV
[SA, Main PCB]
(Stops)
Normal speed
85 ° C
(185 ° F)
(Stop)
2-29
Operation of Control Parts
SA Ribbon Motor F
(Take-up Side)
Thermistor
J102 J107
17 2
RBMTH
18
1
[SA, Ribbon PCB]
M
CL-S6621