Tektronix 323, Instruction Manual

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O perating Instructions— Type 3 2 3
The charging characteristics of NiCd cells vary with the
temperature existing during charge time. A cell which ob­
tained a full charge in a given thermal environment will
deliver more energy than an identical cell which was fully
charged under higher temperature conditions. Cells can be
expected to become warmer as the fully 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 de­
pendent principally upon the cell temperature during the
first three-quarters to seven-eighths of a full-charge cycle.
The Power Pack is normally put on charge without remov­
ing it from the Oscilloscope. However, it can be charged
while it is outside of the Oscilloscope. This permits better
air circulation around the pack, thus maintaining a cooler
battery temperature. Slightly more energy will therefore be
stored in the cells, providing a little longer battery-operated
cycle. In addition, the ability to be charged independent
of the Oscilloscope permits continuous internal battery pow­
ered use if a second Power Pack is obtained. Less than 1
minute is required for exchanging Power Packs.
If NiCd cells become reverse charged, their ability to
be re-charged can be impaired or destroyed. The battery
charger is designed to prevent accidental application of
reverse charging current. However, an unbalance between
cells in a battery can develop during operation or during
partial charging. It is possible for the unbalance to become
so great that during discharge the weakest cells completely
lose their charge and then become reverse-charged by the
current from the strong cells.
Considering that the battery initially consists of equal-
quality cells, the obvious method for avoiding reverse­
charging of an individual cell is to keep the cells equally
charged. This can be done by completing a full-charge
cycle, which consists of applying FULL CHG current for
16 hours. The full charge cycle should be completed in
preference to a partial charge cycle whenever possible. In
addition, approximately once a month or every 15 charge-
discharge cycles (whichever occurs first) the battery should
be charged at a FULL CHG rate for approximately 24 hours.
Once the battery has been fully charged, the Power Pack
switch should be placed at TRICKLE CHG and the AC power
cord should be left connected. This will keep the battery
in a fully charged condition.
Although partial recharging of NiCd batteries is not
recommended as a common practice, occasional partial
recharges can be tolerated. About 30 to 45 minutes of
operating time can be expected as a result of a 1 hour
charge period.
The energy-storing capability of the NiCd cells decreases
gradually with age and the number of charge-discharge
cycles. However, the battery should provide a useful operat­
ing life well in excess of several hundred charge-discharge
cycles.
Storage
NiCd cells can be stored either fully or partially charged.
Storage temperature may be between —40° and +120° F,
but the self-discharge rate increases with temperature. At
70° F, a fully charged cell can be expected to self-discharge
down to about 50% in three months. Cells and Power Packs
which are not in use should therefore be given a full re­
charge at least every three to six months to avoid their
becoming reverse-charged.
Maintenance and Repair
Additional data regarding maintenance and repair of
the Power Pack and the NiCd cells can be found in the
Maintenance section of this manual.
FIRST TIME OPERATION
This first time operation is designed to obtain a trace
and provide familiarization with the Oscilloscope controls
and responses. A control setup chart is provided in Fig. 2-4.
It can be duplicated as a convenient method of recording
specific setups in conjunction with Oscilloscope familiariza­
tion and use.
CAUTION
1. Internal battery-pow ered operation should not
be continued fo r long periods a fte r the LOW BATT
lamp starts flashing. Damage to the NiCd b a t­
tery may result. If the battery becomes sufficiently
discharged, the trace w ill disappear and the light
w ill cease flashing. The battery should then be
recharged to avoid the possibility o f individual
cells becoming reverse-charged.
Operation can
continue during recharging.
2. Alw ays operate w ithin the Oscilloscope’s a l­
low able input values, which are as follow s:
Power Source-AC
W ired fo r 1 1 5 V
operation:
W ired fo r 230 V
operation:
Power Source-DC
VERT INPUT
EXT TRIG OR
HORIZ INPUT
EXT BLANK
48 to 440 Hz
90 to 136 V
180 to 272 V
6 to 16 V
500 V DC +
peak AC
300 V DC +
peak AC
150 V DC +
peak AC
WARNING
Unless the Type 323 Oscilloscope is connected
to a common ground, its m etallic parts w ill be ele­
vated to the signal potential to which it is con­
nected. The ground loop must always be com­
pleted fo r normal operation o f the Type 323
Oscilloscope. Unreliable results and unsafe con­
ditions w ill otherwise exist. Connect a lead be­
tween Oscilloscope ground and equipment ground
before connecting the Oscilloscope inputs to equip­
ment test points. Do not remove the ground lead
until a ll other connections are removed.
1. Preset the controls as follows:
VOLTS/DIV 5 DIV CAL
VARIABLE (VOLTS/DIV) CAL
INPUT GND
X 10 VERT GAIN In
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