2.2.6 Over Voltage Protection Circuit
As described in 2.2.5, the power supply circuit of this
unit not only uses the voltage regulator circuit to
stabilize the output voltage
and provide feedback to the switching circuit, but it also contains an over
voltage protection circuit to protect against malfunctions of the voltage regulator circuit.
Figure 2-18 shows the over voltage protection circuit.
If the voltage regulator circuit malfunctions and the output voltage
goes over the limit:
+
= 4 0 [ V ] ,
then the photodiode in PC2 receives current. Consequently, the gate of the thyristor
on the receiver
side conducts to pass the base current of
off so that the Potential at
reduces to O [V] and no voltage is induced in the secondary side winding T1-3. The power supply must
be switched off to reset the protection circuit.
the same way, over voltage protection is
for the output
of the +5
regulator
to Section 2.2.5.). When the
reaches 6 V or
the
is Performed.
1 4 T 2
o
“
TY1
Q“
R7
I
C14
, D20
●
C20 z
22
3
Vo
.. .
Figure 2-18. Over Voltage Protection Circuit
2-24
Содержание LQ-1060
Страница 1: ...EPSON TERMINAL PRINTER L Q 8 6 0 1 0 6 0 TECHNICAL MANUAL ...
Страница 5: ...REVISION TABLE REVISION DATE ISSUED I CHANGE DOCUMENT I I 1st issue I v ...
Страница 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 ...
Страница 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 ...
Страница 203: ...Figure 5 6 MONPS MONPSE Board Voltage Waveforms 5 17 ...
Страница 204: ...REV A Fiaure 5 6 MONPS MONPSE Board Voltage Waveforms z L 5 18 ...
Страница 205: ...Figure 5 6 MONPS MONPSE Board Voltage Waveforms 5 19 ...
Страница 217: ... n 3 m I BUS CONTROL 1 LJ Pc II SYSTEM CONTROL I I L 1 I PERIPHERAL BUS IIF u lJ Figure A 2 PD78213 Block Diagram A 3 ...
Страница 248: ...REV A A 3 DRAWINGS 3 J32 J TI g 4 Figure A 27 MONPS Board Component Layout A 34 ...
Страница 249: ... J30 33r J32 d m b13 G a TI 7 IC20 r El m J24 C2 L cl mow B L U E u Figure A 28 MONPSE Board Component Layout A 35 ...
Страница 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 ...
Страница 251: ...REV A 1 UXZO xl OX 9 xl Onz b 8M 118 en A N J 93 T 818 Figure A 30 MONPSE Board Circuit Diagram A 37 ...
Страница 252: ...L t g Figure A 31 JUNMM Board Component Layout A 38 ...