– 74 –
5.
Waveform with Oscilloscope
(1) Crystal (12 MHz)
(2) RESET (Power on reset)
Crystal
Pin 28 of IC7
Upper
: RESET input
Pin 1 of IC5
Time/Div : 0.2
µ
s
Lower
: RESET output Pin 3 of IC5
Volt/Div
: 1V
Time/Div : 10 ms
Volt/Div
: 2V
(3) Protection Circuit
(4) Head Energizing Control Signal
Upper
: RESET
Pin 3 of IC5
Upper
: HDEN
Pin 111 of IC4
Lower
: Drive
Collector of TR9
Lower
: HD1 Data
Pin 67 of IC4
Time/Div : 5 ms
Time/Div : 50
µ
s
Volt/Div
: Upper 2V
Volt/Div
: Upper 1V
Lower 2V
Lower 2V
(5) Print Head Control Signal and Waveform
(6) Carriage Motor Control Signal and Driving Signal
Upper
: HD1 Data
Pin 67 of IC4
Upper
: Carriage-ø1 Control Signal Pin 31 of IC4
Lower
: HD1
Pin 2 of TA1
Lower
: Carriage-ø1 Driving Signal Pin 3 of CN8
Time/Div : 0.1 ms
Time/Div : 2 ms
Volt/Div
: Upper 5V
Volt/Div
: Upper 5V
Lower 10V
Lower 20V
(2V)
(0V)
(4V)
(0V)
(4V)
(0V)
(4V)
(0V)
(4V)
(0V)
(0V)
(4V)
(0V)
(4V)
(5V)
(0V)
(40V)
(0V)
(5V)
(0V)
(0V)
(100V)
Summary of Contents for LC-8521
Page 1: ...DOT MATRIX PRINTER LC 8521 TECHNICAL MANUAL THIRD EDITION ...
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Page 101: ... 97 Blank Page ...
Page 102: ... 98 4 Wiring Scheme of Printer ...
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Page 104: ... 100 5 Electrical Parts 5 1 Main Logic Board 5 1 1 Circuit Diagram ...
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Page 107: ... 103 Blank Page ...
Page 108: ... 104 5 1 2 Component Layout ...
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Page 116: ... 112 5 4 Power Supply Unit 5 4 1 Circuit Diagram ...
Page 117: ... 113 5 4 2 Component Layout ...
Page 120: ... 116 6 Serial Parallel Converter Board Option 6 1 Wiring Scheme ...