Tektronix 422, Instruction Manual

Page: 105 / 213

Performance Check/Calibration—Type 422 AC-DC
TABLE 5-1
Power Supply O utput Voltage and Ripple
Power Supply Output Voltage Range Maximum Ripple2 (peak to peak)
High Frequency
AC Line Frequency
— 12 volt
—11.9 to —12,1 volts
20 m illivolts 8 m illivolts
+ 12 volt
+ 11.7 to + 12.3 volts
20 m illivolts 8 m illivolts
+ 55 volt
+ 53.9 to 50.3 volts
2 volt
+ 95 volt
+ 93.1 to + 97 9 volts
0.4 volt
+ 10.5 volt
+ 10.3 to + 10.7 volts
1 m illivolt 1 m illivo lt
-8 1 volt
—80 to —82 volts
20 m illivolts 8 m illivolts
2 Disregard fast spikes; see Fig. 5-5.
Fig. 5-4. Location of +10.5-volt and -81-volt power supply test
points (Calibrator and Regulators board).
f. CHECK—Each supply w ith the precision DC voltmeter
fo r the tolerances given in Table 5-1.
g. Disconnect the voltmeter.
4. Check DC Ripple
a. Set the test oscilloscope for a vertical deflection
factor of 10 m illivolts/division, AC coupled, at a sweep rate
o f 20 microseconds/division ( IX probe connected to
vertical input connector).
b. CHECK—Test oscilloscope display fo r maximum
ripple of each supply as listed in Table 5-1. Fig. 5-5 shows a
typical display of ripple and the levels between which the
ripple measurement should be made. Power supply test
points are shown in Fig. 5-2 and 5-4. Change the test
oscilloscope vertical deflection factor as necessary to
provide the correct display of ripple.
c. Set the variable DC power supply fo r +22-volts
output.
d. CHECK—Ripple of each supply fo r tolerances given in
Table 5-1.
c. Set the variable DC power supply fo r +22-volts out­
put.
d. CHECK—Each supply w ith the precision DC vo lt­
meter fo r the tolerances given in Table 5-1.
e. Set the variable DC power supply for +35-volts
output.
e. Set the variable DC power supply fo r +11.5-volts o u t­
put.
f. C H EC K-R ipple of each supply for tolerances given in
Table 5-1.
g. Disconnect the variable DC power supply and the test
oscilloscope.
5-11