Tektronix 321A Instruction Manual page 8

Preliminary Instructions - Type 321 A
1s set to LOW or HIGH, the ac rectifier is connected to the
battery charger circuit which, in turn, provides charging cur-
rent to the internal rechargeable batteries.
NOTE
If dry cells
ore
used instead of rechargeable bat-
teries, then the Charger switch must be set to DRY
CELLS to disconnect the charger circuit. For further
information about battery operation, refer to the
topics tilled "Battery Operation" and "Battery
Charger" appearing in this section of the manual.
If the Type 321 A is being operated exclusively from the
oc line and the internal batteries ore removed, the Charger
switch can remain in the DRY CELLS position to disconnect
the charger circuit. If you prefer to completely turn off
oil power to the Type 321 A, set the POWER switch to
TRICKlE and either disconnect the power cord from the
ac line or turn off the power at o wall switch (or equiv-
alent).
Battery Operation
Operation from the internal battery source can be accom-
plished by using:
1. Ten size D flashlight cells (approximately
1 /
1
-hour con-
tinuous operation, more with intermittent operation), or
2.
Ten size D Alkaline cells such as Eveready E95, Burgess
Al-2, or Mallory MN-1300 (about
2
1
/ 2
hours continuous
operation), or
3. Ten size D nickel-cadmium rechargeable cells (up to
about 5 hours continuous operation, depending on the
type used).
The nickel-cadmium cells ore the most practical type where
considerable battery operation is planned .
To install the cells, ftrst open the battery cover as illus-
trated in Fig. 2-3. Next, install the batteries by following
the procedure given in Fig. 2-4.
CAUTION
Be sure to observe cell po larity indicated on the
battery cover.
To turn on the Type 321A when operating from the internal
batteries, set the POWER switch to BATT ON. To turn off the
oscilloscope, set the POWER switch to one of the OFF posi-
tions-FULL or TRICKLE. These OFF positions disconnect
the batteries from the oscilloscope load (1 0-volt regulated
supply) so there is no battery drain. To charge the recharge-
able batteries, refer to the next topic titled " Battery Charger" .
Fig. 2·3 • .Removing lhe baii••Y cover from the Typ• 321 A Oscllloltope.
2-2