2.2.7 +5 V Switching Regulator Circuit
Figure 2-19 shows the +5
switching regulator. This circuit employs a hybrid type switching regulator
STR20005
which consists of a voltage regulator circuit along with coil
and capacitor
at
the external output section.
To
Voltage
Protection Circuit
t
-
4
L
ST R
2 0 0 0 5
20)
I
- - - - 1
I
R3
R4
I
I
, CIRCUIT
I
– Reference
,
●
I
R5
I
L
23
+5 v
Figure 2-19.
+5 V Switching Regulator Circuit
2.2.7.1 Activation
When the +35
rises, the start circuit
is activated, and a reference voltage is applied to the
positive terminal of comparator
in
Since the negative side of
still remains at O [V] at this
time, the
output goes HIGH, Trf is turned on so that current flows from the emitter to the collector,
and the +5 V line turns on.
2.2.7.2
Voltage Regulator Circuit
Resistors R4 and
in
regulate the
V output voltage.
and
compose a differentiation
circuit and prevent noise and abnormal oscillation.
The output voltage is fed back from two
of
and is delivered to R4 and and then input to the
negative side of
The voltage input to the negative side regulates the output voltage by controlling the on-time of Trl. It is
compared with the reference voltage, and if it is larger than +5 V, it switches on the
output so as
to turn on
This operation is called Pulse Width Modulation
control. Figure 2-20 shows the
sequence.
2-25
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 ...