W A R N I N G I
Change o f ac voltage must be accomplished by
qualified service personnel.
AC Power Source Operation
The AC Input Voltage Selector switch permits the 305
to be operated from a 115 or 230 volt ac nominal line vo lt
age source, at 48 to 440 hertz I Figure 1) The Power Source
Selector switch must be set to the proper AC position. The
ac line voltage fuse must be changed when selecting a d if
ferent nominal line voltage. A n y fuse change requires re
moval o f the instrument cabinet and must be accomplished
by qualified service personnel.
INTERNAL BATTERY OPERATION
W A R N I N G I
Change o r replacement o f batteries must be accom
plished by qualified service personnel
I ne
j u d
teatures oattery operation irom six recuarye-
able nickel-cadmium cells (1.2 volts each, total nominal
voltage o f 7.2 Vdc). The operating tim e o f the internal
batteries depends upon display intensity, state o f battery
charge, discharge temperatures, and the instrument function
being used; oscilloscope, DMM, or both. When the instru
ment is operated at +20°C to +303C (+C8 F to +86°F),
the typical operating time o f fu lly charged batteries w ith
both oscilloscope and DMM in operation is approximately
1.6 hours.
A light-em itting diode (LED), labeled 'ON (FLASHES
WHEN LOW)', is steadily illum inated to indicate that the
instrument oscilloscope function is on, and the battery
charge is sufficient fo r operation. When battery charge is
low, the LED flashes on and o ff indicating that batteries
require recharge or possible replacement. An automatic
battery over-discharge protection circ u it w ill turn the instru
ment o ff to prevent excessive discharge, which could result
in permanent battery damage.
During DMM operation, the digital readout alternates
between a normal display a n d ---------------i f the power
source voltage drops to o low for proper DMM operation.
4
305 Operators
REV A SEP 1979