Pf Motor Temperature Sensor - Citizen CL-S6621 Technical Manual

Operation of Control Parts

(5) PF motor temperature sensor

The PF motor temperature sensor is used to detect the temperature of the "SA PF Motor". This
sensor is a thermistor bonded to the "SA PF Motor". Since the resistance of the thermistor
changes according to a temperature change, the voltage at pin 8 (PFTMP) of U1A (CPU)
changes accordingly. The CPU senses the voltage at pin 8 (PFTMP) to detect the PF motor
temperature.
U1A
CPU
PFTMP
ANI3
8
U14
FPGA
nTEMP_ENABLE
B2_28
C11
nTEMP_ERROR
B2_27
C6
Printing operation when motor temperature rises:
When the temperature of the "SA PF Motor" rises above 90°C (194°F), printing speed is
reduced to avoid overheating. If it reaches 95°C (203°F), the "SA PF Motor" 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 PF Motor" falls below 85°C (185°F), the LEDs stop blink and
printing will be resumed.
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 U16A detects if the level at pin 8 (PFTMP) (i.e., the temperature of the "SA PF
Motor") 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.)
CL-S6621
+3.3V
R40
R41
R42
C41
Error: Low
Normal speed
85°C
(Stop)
(185°F)
+3.3V
R63
R64
C94
TEMP ERROR Detection
+3.3V
R39
U16A
3
PFTMP
+
1
2
-
BA2903SFV
[SA, Main PCB]
Low speed
90°C
(194°F)
2-28
SA PF Motor
Thermistor
J7
1
M
2
(Stops)
95°C
(Stop) (203°F)