Internal Checks And Adjustments - HP 8082A Operating And Service Manual

INTERNAL CHECKS
AND ADJUSTMENTS
The internal checks and adjustments section
(Tables 6-14 to 5-26) gives the procedure for adjusting
a serviceable instrument to bring it within specification.
The checks should be performed in the order in which
they appear. A summary of adjustments and selectable
components is presented in Table 5-14. Figure 5-2 at
the end of this section gives the locations of the
adjustments.
NOTE:
Ensure that BDTH outputs of the 8082A are
terminated by a 50 52 load whenever pulse measure-
ments or adjustments are to be made.
USING THE 15266A TEST BOX
The Test Box is designed to facilitate
troubleshooting and adjustments of the current sources
in Board A5 It is connected in place of Board A4 and
simulates the load presented to Board A5. A switch on
the Test Box sek?cts the parameter for monitoring on the
externally-connected DVM. The checks and adjustments
which can be performed by the Test Box are sum-
marized in Table 5-16.
To connect the Test Box, refer to Figure
5 - 4 5
5-l and use the following procedure:
Switch 8082A off. Remove the 8082A top cover.
Remove the two screws from the Output Amplifier
(board A4) heat sink on the rear of the 8082A. Unplug
the Dutput Amplifier from its connector by about 2 cm
and carfully push the connector-end of the board to one
side.
WARNING
Any interuption of the protective (grounding) conduc-
tor inside or outside the instrument or disconnection of
the protective earth terminal is likely to make the appa-
ratus dangerous. fntentional
Any adjustment, maintenance, and repair of the opened
instrument under voltage should be avoided as much as
possible and, when inevitable, should be carried out
only by a skilled person who is aware of the hazard in-
volved. The opening of covers or removal of parts,
except those to which access can be gained by hand, may
expose live parts, and also accessible terminals may be
live.
ADJUSTMENTS
interruption is prohibited.
Disconnect the three ribbon cables:
A5 W8 from A4 Jl
A5 W7 from A4 J2
A9 W9 from A5 J-ATT
Connect the extender board to the X4 socket (socket
from which board A4 has been disconnected).
Connect the other extender cable to the J-ATT connec-
tor on board A5
Connect the ends of cables Jl, 52, J-ATT
Test Box as shown in Figure 5-l.
Connect DVM (floating mode, auto range) and verify
operation of Test Box by performing first check in
Table 5-16.
6-46 SAFETY CHECK
5-47 This check (Table 5-27) should be per-
formed following the internal checks and adjustments to
verify the instrument safety.
5-49
The quadruple AND gate A3 U6 in the rep
rate circuit can be damaged if the -5V or -lOV supplies
are shorted to ground
Instruments with serial numbers
switching transition times from 5-50~
occurs, insert diode CR 37 (partnumber
in series with A5 Q37 (anode to collector).
Capacitors inside the instrument may still be charged
even if the instrument has been disconnected from its
source of supply.
Make sure that only fuses with the required rated cur-
rent and of the specified type (normal blow, time delay,
etc.) are used for replacement. The use of repaired
fuses and the short-circuiting of fusehoiders
avoided.
Whenever it is likely that the protection has been
impaired, the instrument must be made inoperative
and be secured against any unintended operation.
and X5 to the
to 50p--05m.
must be