Tektronix 502 series, Instruction Manual

Page: 11 / 114

PRELIM INARY INSTRUCTIONS
Cooling
A fan maintains safe operating temperature in
the Type 502 Oscilloscope by circulating air
through a filter and over the components. There­
fore, the instrument must be placed so that the
air intake is not blocked. The air filter must be
kept clean to permit adequate air circulation. If
the interior temperature should rise too high, for
some reason, a thermal cutout switch will discon­
nect the power and keep it disconnected until
the temperature drops to a safe value.
IM PO R TA NT: For p roper air circu la­
tion, the bottom and side panels
must be in place. Be sure the bottom
p an el is installed according to direc­
tions.
Power Requirements
The regulated power supplies in the Type 502
will operate with line voltages from 105 to 125
volts, at 117 nominal line volts, or from 210 to
250 volts at 234 nominal line volts. Proportionate
line voltage variations apply when other nominal
line voltage primary connections are made. For
maximum dependability and long life the voltage
should be near the center of this range.
Voltages outside of these limits, or poor line-
voltage waveforms, may cause hum or jitter on
the trace and may cause unstable operation. Be
sure to check for proper line voltage if indica­
tions such as these are present.
The Type 502 is equipped with a special
power transformer. This transformer has a group
of primary terminals whch allows you to connect
the primary windings for use on six different in­
put voltages. The line voltage for which your
transformer is connected is indicated on the
metal tag at the rear of the instrument. Fig. 2-1
shows the primary connections for all the input
voltages.
D A
M
1 4
t no v f
B
1 4
t 124 V f
• ............ m
s * s *
B C
• •
1 4
+ 220 V f
w§mmm
D A
M H i
2 3
« 2 n H M
B I
w
8 #
'mmmMmrnmmmmmmm
c •
1
4
1 4
t 234 V f
t 248 V t
Fig. 2-1. The power transformer has two extra wind­
ings permitting nominal primary voltages of 110, 117,
124, 22 0, 234 or 248 volt, 50 or 60 cycle operation.
® PRELIMINARY INSTRUCTIONS — TYPE 502
2-1