Example Paper-End Signal Detection Circuit - Epson M-T123 Designer's Manual

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1.4 Example Paper-end Signal Detection Circuit

1) The example circuit for detecting the paper-end signal is as shown in Figure 1.4.1.
[Printer side]
Figure 1.4.1 Example Paper-end Signal Detection Circuit
2) To detect a paper end, sample signals for each dot line. If LOW is found two or more times
consecutively, this is interpreted as a paper end.
3) The threshold level of HIGH and LOW is 2.5 ± 0.2 V (VDD = 5 VDC ± 5%).
4) If a paper end is detected, printing is stopped. However, if a paper end is detected while printing, it
is possible to print 15 dot lines or less (30 steps for the motor) from the position when a paper end is
interpreted.
EPSON
27
29
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270 Ω ± 5%
TITLE
M-T123
Designer's Guide
(STANDARD)
2.2 kΩ ± 5%
3.3 kΩ
+
Comparator
–
1 kΩ
LM2903
2.2 kΩ ± 5%
[User side]
SHEET
REVISION
A
VDD 5V
Paper-end
detection signal
GND
NO.
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