Operating Power Information; Internal Battery Operation; Battery Charging - Tektronix 213 DMM Instruction Manual

Operating lnstructions-213 Service
R1
SCOPE INPUT
RESISTANCE
SCOPE VERTICAL
DEFLECTION
MULTIPLICATION
FACTOR
(BLANK= 1)
R2
INPUT RESISTANCE
AT PROBE TIP
PROBE
ATTENUATION
PROBE TIP
RESISTANCE
R2
R1
R2 - R1
~
Tektronix
Part No.
204-0594-03
Probe Marking
1480-17A
Fig. 2-5. Probe Body Assembly identification.
OPERATING POWER INFORMATION
Internal Battery Operation
This instrument features battery operation from two inter-
nal rechargeable nickel-cadmium cells. The operating time
of the internal batteries depends upon display intensity,
battery charge and discharge temperature, and the function
(DMM or Oscilloscope) being used. When the batteries are
charged and operated at +20 to +30°C (+68 to +86°F), the
typical operating time of fully charged batteries at maxi-
mum display intensity in the DMM mode of operation is
3.5 hours.
A light-emitting diode (LED), labeled PWR (BTRY), indi-
cates that the instrument is on and the battery charge is
sufficient for operation. When the battery charge is low,
the LED extinguishes. Within 4 to 10 minutes after the
LED extinguishes, an automatic battery deep discharge
protection circuit will turn the instrument off. This pre-
vents excessive discharge which would result in battery
damage.
Battery Charging
To charge the batteries, connect the instrument to the po-
wer line and allow at least 16 hours for the batteries to
2-4
reach full charge. To obtain the longest operating life for
the batteries, the instrument should be turned on at least
once a month and the batteries discharged, and then re-
charged for 24 hours. This procedure balances the charge
on the batteries and reduces the possibility of either cell
becoming reverse charged. This instrument can be opera-
ted while the batteries are being charged.
NOTE
If the instrument does not operate with ac
power applied, and the PWR (BTRY) indica-
tor does not light, the power line fuse may
be blown. See Fuse Replacement in Section
4 for instructions.
The energy capacity of nickel-cadmium cells varies with
the temperature at which they are charged and operated.
Table 2-1 shows the percentage of full charge capaci Ly al
various charging and operating temperatures.
Nickel-cadmium cells will self-discharge when the instru-
ment is not used or is stored for extended periods of time.
The rate of self-discharge is dependent upon temperature
and humidity. When the instrument is to be stored for ex-
tended periods of time, particularly at high temperature or
REV APR 1982