Epson TM-U675 Service Manual page 252

Confidential
Table D-12 Detection circuits
Detector Function
Impact Head Head
Temperature temperature
Thermal Head Head
Temperature temperature
Carriage Mechanism
Motor
Step-Out
Home Mechanism
Position
Lever Timing Mechanism
Detector
Front Cover Case
Rear Cover Case
Rear Cover Case
TM-H6000
EP Timing EP unit
Pulse
EP Reset EP unit
DIPSW
Appendix D-64 Product Overview
Type of
Sensor Circuit
Thermistor VCC potential voltage ratio of thermistor resistance value and
R72 is read by the AD port of the CPU
Thermistor VCC potential voltage ratio of thermistor resistance value and
R126 is read by the AD port of the CPU
Transparent Base of Q50 is driven by voltage drop of load resistor (R90);
photo phase data with no delay is taken out; and logical judgment is
performed by the GA port
Photo IC Logical judgment of photo IC output is performed by the GA
port
Photo IC Logical judgment of photo IC output is performed by the GA
port
Transparent Logical judgment of load resistor (R88) voltage drop is
photo performed by GA port
Transparent This signal is used for thermal unit sensor
photo
Photo IC Logical judgment of photo IC output is performed by the GA
port
Tacho-gene Waveform shaping (Q19) of sine wave output, and processing
by the CPU interrupt port with hysteresis (U28)
Read switch Logical judgment of the GA port with time constant
DIPSW Pull-up by resistor group (RM1, 2, 3, 4). "L" is read at On. Logical
judgment is performed by the CPU, GA
Rev.D