Operating Instructions—Type 324
Slip-on connectors in the Power Pack must be connected
in accordance w ith the line voltage to be used. The internal
fuse must also be changed when the AC line voltage is
changed. Spare fuses are contained inside the oscilloscope
adjacent to the side panel. The foliowing procedure ex
plains the Power Pack removal, connection changes, and
Power Pack replacement.
Power Pack Removal.
Disconnect all cables from the
oscilloscope and set the oscilloscope Power Pack switch at
EXT DC.
color code agrees w ith that w ritten on the terminal m ount
ing. See Fig. 2-1C. Be careful to avoid pinching your fingers
at the fro n t panel when the oscilloscope cover is replaced.
IM P O R T A N T
The oscilloscope w ill n o t operate fro m the in te rn a l
batteries o r fro m an A C source i f the Power Pack
sw itch is le ft in the E X T DC p o sitio n . However, i f the
sw itch is le ft in this p o s itio n and A C is
, the
batteries w ill charge a t a full-charge
Remove the cover-securing screw from the back of the
case. See Fig. 2-1 A.
Grip the fro n t edge of the oscilloscope w ith one hand,
and the cover assembly with the other hand as shown in
Fig. 2-1B. Pull the cover assembly o ff the chassis, main
taining a firm grip on the fro n t of the chassis.
Set the oscilloscope chassis down on a fla t surface. Dis
connect the three interconnecting leads and release the
Power Pack securing clamp. See Fig. 2-1C.
Move the Power Pack approximately one-quarter inch
toward the rear of the chassis to release the positioning
lugs. Then remove the Pack sideways from its mounting
area. Use caution to avoid striking transformer wires or the
circuit board against the oscilloscope chassis.
The batteries used in the Power Pack are capable o f
delivering a large a m o u n t o f energy in a sh o rt time.
Rings, watch bands, o r o th e r m e ta llic item s which
s h o rt-c irc u it the b a tte ry can ra p id ly become h o t
enough to cause severe burns. Keeping the Power
Pack sw itch a t E X T DC m inim izes the num ber o f
p o in ts in the c irc u itry to which the b a tte ry voltage is
applied.
L in e V o lta g e C o n v e rs io n .
F ig. 2-1C illustrates
the location of the jumper wires and Fig. 2-1D illustrates
the details of the Power Pack. The two possible circuit
arrangements, accompanying fuse sizes and the locations of
spare fuses are indicated in Fig. 2-2. Re-install the insulated
tubing over the unused AC terminals.
Charging
Although the batteries contained in the Type 324
Oscilloscope are charged before packaging, they should re
charge fo r 16 hours at a FU LL CHG rate when put into
service.
The charging characteristics of NiCd cells vary w ith the
temperature existing during charge time. A cell which ob
tained a full charge in a given thermal environment w ill
deliver more energy than an identical cell which was fu lly
charged under higher temperature conditions. Cells can be
expected to become warmer as the fu lly charged point is
approached, despite ambient conditions. This is a natural
phenomenon which has little effect upon the energy which
the cell can retain, since the amount of total charge is
dependent principally upon the cell temperature during the
first three-quarters to seven-eighths of a full-charge cycle.
Location of spare fuses for AC line circuit and Power Regula
tor circuit.
(A ) Spare fuse location.
Low
Line
C
□
□
E
High
Line
(B) Low Line connection
Fuse size—0.4 A
(C) High Line connection
Fuse size—0.2 A
Power Pack Replacement.
Replace the Power Pack by
reversing the removal procedure, insuring that the wire
Fig. 2-2. (A) Location of spare fuses. (B) Connection changes for
nominal AC line voltages.
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