HP 5501A Operating And Service Manual page 54

Model 5501A
Circuit Diagrams
TRUTH TABLE
NON-INVERTING BALANCE
INPUT
BALANCE
INPUT
Figure 7-2. IC Diagrams (cont'd)
INVERTING
INPUT
OUTPUT
4
NON-INVERTING N C
INPUT
v
-
NOTE PIN 4 CONNECTED TO CASE
1826-0035
(
LM308A)
OPERATIONAL AMPLIFIER
v-
NOTE +=NON-INVERTING INPUT (PIN 2)
MORE POSITIVE T H A N INVERTING
INPUT (PIN 3)
-=INVERTING INPUT (PIN 3) MORE
POSITIVE T H A N NON-INVERTINGGINPUT
1826-0065 (LM311)
VOLTAGE COMPARATOR