S6V Over Current Protection Circuit; Output On/Off Circuit; On/Off Control Circuit - Toshiba TLP411E Technical Training Manual

2-10. +6V, +S6V Over Current Protection
Circuit
As shown in Fig. 1-12, this circuit detects the over current
by differential amplifier consisting of Q102 and Q103.
The reference voltage is produced by voltage division of
R105 and R106 using the +S6V as voltage source. This
voltage called VA (+S6V x R106/R105 + R106) is
compared with Voltage VB (Ioc x R108) generated by over
current. Q101 and Q102 turn on under the VA < VB
condition, by means of which the current is supplied to
PC001. This is transferred to the primary control circuit.
The rest of operation is the same as item 2-9.
To +15.5V
Q101
R104
Q102
PC001
R106
R108
VA
Fig. 1-12

2-11. Output ON/OFF Circuit

+15.5V and +10V outputs can be turned on/off by 4-ter-
minal regulators IC401 and IC201. +5V and +6V outputs
can be turned on/off by POWER MOSS FET (Q106,
Q302). ON/OFF signal is given by the following ON/OFF
control circuit.

2-12. ON/OFF Control Circuit

This circuit controls the circuit of item 2-11, which de-
lays the external signal by the integration circuits (R118
and C108) to send signals to each output circuit. Signal
level is TTL level. Each output becomes off at "L" and
becomes on at "H" approximately 300 ms later.
The ON/OFF signal of +12V is input from pin 2 of CN104
and turns Q302 ON/OFF passing through Q301 and PC101.
+S6V, +6V line
R105 R107
Q103
C103
VB
G
+S6V, +6V current
1-6