2.2.2 Input Filter Circuit
Figure 2-11 shows the input filter circuit. The filter circuit attenuates external noise and inhibits noise
generated in the printer from
going
out over
AC line. The coils and capacitors employed in this filter
are able to handle ‘fluctuations of the AC input line. Frame ground (F. G.) is connected between
and
which handle leakage current from the frame to the AC line.
A C
C3
Figure 2-11. Input Filter Circuit
2.2.3 Rectifier, Smoothing, and Surge-Suppression Circuit
As shown in Figure 2-12, the AC input voltage filtered by the input filter is full-wave rectified by diode bridge
DBI, and is smoothed by
The voltage across C6 is normally O [V] before the power is turned on.
Therefore, the initial input current is shorted by C6 via DB1 and a large charging current (called a surge
current) flows when the power is turned on. Figure 2-13 shows the surge current.
The largest surge current flows if the power supply
FILTER
CIRCUIT
T2
TY
I
G
is turned on at the peak of the input voltage.
SURGE
I
L
CIRCUIT
v
INPUT VOLTAGE
TO
I
O N
Figure 2-12. Rectifier-Smoothing-Surge Suppression Circuit
Figure 2-13. Surge Current
The voltage across C6 increases after the
is applied, and the current is accordingly stabilized. Until
the voltage across C6 becomes stable, the surge current is limited by a resistor RI in series with capacitor
When 120
VAC is applied, the voltage
C6 increases to about 160 VDC. In this circuit, the surge
current is limited to around 23 A, based on the formula: 160 /
= 23.5 [A] .
After C6 is fully charged, resistor RI is shorted to keep its temperature low. The circuit includes
for this purpose, which shorts TI to T2 by passing current
to the gate. (When C6 is charged, power is
applied to coil
of transformer so that a voltage is induced in coil T9-10. When this voltage reaches
1.5 V,
flows to switch on
2-19
Summary of Contents for LQ-1060
Page 1: ...EPSON TERMINAL PRINTER L Q 8 6 0 1 0 6 0 TECHNICAL MANUAL ...
Page 5: ...REVISION TABLE REVISION DATE ISSUED I CHANGE DOCUMENT I I 1st issue I v ...
Page 68: ...cc o REV A N N n 1 cc b I al cc u co n4 2 1 Figure 2 14 Main Switching 2 21 ...
Page 79: ...REV A Table 2 20 State of Module 1 1 I W stay E H H L H d O s H H 4 2 32 ...
Page 203: ...Figure 5 6 MONPS MONPSE Board Voltage Waveforms 5 17 ...
Page 204: ...REV A Fiaure 5 6 MONPS MONPSE Board Voltage Waveforms z L 5 18 ...
Page 205: ...Figure 5 6 MONPS MONPSE Board Voltage Waveforms 5 19 ...
Page 248: ...REV A A 3 DRAWINGS 3 J32 J TI g 4 Figure A 27 MONPS Board Component Layout A 34 ...
Page 250: ... 2 1 1 1 1 I A b 2 Ozaz 1202 C O ZZH Z UOEE vu I 1 Figure A 29 MONPS Board Circuit Diagram ...
Page 252: ...L t g Figure A 31 JUNMM Board Component Layout A 38 ...