PURPOSE
OF
RELAYS,
CONTACTS
AND
SWITCHES
Motor
Control Relay
The primary function of this relay
is
to prevent
starting of the machine
by
any means other than
by
depression of the start
key.
This relay
is
picked up
when the start key
is
depressed and remains energized
as
long
as
the machine
is
running.
When
the machine
runs out of cards, the runout capacitor discharges
through this relay, holding it energized long enough
for the
MC-BL
point to keep the motor relay energized
and the drive motor running until the last card in the
machine
is
fed
to its proper pocket.
The MC-AL point, in conjunction with card lever
contact 2, completes a hold circuit to the motor control
relay.
In
its
N/O
condition, this relay point prevents
the energization of the above relay except
by
means
of the start key in the event the machine
was
stopped
with cards in the feed.
The
MC-AU point prevents a back circuit which
would make the contact roll hot
if
the machine
was
stopped with cards in the
feed
and the contact roll
cover
was
raised.
The MC-BL point completes a circuit
to
pick the
motor relay and hold it energized during automatic
machine operation.
Motor
Relay
This relay
is
a heavy duty relay. Its purpose
is
to
complete a circuit to the drive motor.
It
is
picked and
held energized under control of the motor control relay.
As
long
as
the motor relay remains energized, its points
complete a circuit to the drive motor.
Time Delay Relay
The purpose of the time delay relay
is
to
prevent
starting of the machine until the tubes have reached
their proper operating temperature. Upon closing of
the main line switch, current flowing in the
TD
heater
coils causes the TD-A contact strap to
flex,
close its
contact point, and pick the time delay relay. The time
required to close the TD-A point
is
50 to 60 seeconds.
The
TD-BL
N/C
point allows a circuit through the
TD
heater when the main line switch
is
turned on.
32
After the time delay relay has picked, opening of this
point breaks the circuit to the heater coil.
The TD-BL
N/O
point provides a hold circuit for
the time
delay
relay once it has been picked.
The
TD-BU point
r~nders
the start key inoperative
until the time delay relay picks.
Card Lever Contact 1
This contact closes
as
the leading edge of the card
enters the first feed rolls. Closing of this contact allows
sorting of the first card.
Once closed, it remains closed
during the time that cards are continuously feeding
through the machine and, in conjunction with card
lever contact
2,
furnishes circuits
to
the commutator
and the sort magnet for sorting.
Card Lever Contact 2
This contact closes
as
the leading edge of the card
leaves the second feed roll.
Once closed, it remains
closed during the time that cards are continuously
feeding through the machine, and furnishes circuits to
the commutator and sort magnet for sorting and to the
motor control relay for automatic operation. This
con-
tact maintains the necessary circuits for sorting the
last card.
Pocket Stop Contact
This contact
is
normally closed. Opening of this
contact when one or more card pockets become full
renders the runout circuit inoperative and causes
im-
mediate dropout of the motor control relay. Dropout
of this relay opens the MC-BL point, de-energizing the
motor relay and stopping the machine
as
soon
as
its
inertia
is
overcome
by
friction.
Contact Roll Cover Switches 1 and 2
These two switches are held in a closed position
when the contact roll cover
is
lowered. Raising of the
contact roll cover opens both switches, breaking all
machine circuits and removing the potential from the
contact roll. These switches are installed
as
a safety
measure for operating personnel, and their operation
must not be crippled in any
way.
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