A. DC Power Supply
1. Mechanism
The DC power supply PCB supplied with
turned
the DC power supply PCB, the
power
and smoothed
then
lowered by the transformer (T201);
made available
and 5V by filters and
regulator.
For 24V power, the output
checked;
fed
to the switching regulator (Q204) by way
of a photocoupler
for stabilization.
5V power stabilized by the regulator (Q207).
2. Protection Mechanism for Power Supply
The DC powersupply equipped with protection
mechanisms to
off the power should
of the
suffer a
of
error.
The protection mechanism for 24V power the
over-current detection mechanism the switching
regulator (Q204);
activation, the circuit
off 12V and 5V
For 12V power, a
current
to protect against
rent.
The protection mechanism for 5V power makes
use of the over-current detection circuit of the
activation,
off.
power,
protection circuit
isadditionallyprovidedusing aZenerdiode(ZD201)
and thyristor
The output, after activation of these protection
mechanisms, can be recovered by turning the door
switch OFF, correctingthe
load, and turning
the door switch
once again.
If only
has
out, the door switch
should be turned OFF, the relevant load should be
corrected,
should be replaced. and the
door switch should be turned
once again.
D 2 0 4
3-52
protection circuit
24V
Q207
Figure 3-52
CANON INC.
C A N O N
IN
d
Summary of Contents for NP-2120
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