Keithley 486 Instruction Manual page 175

SECTION 7
Maintenance
Table 7-8. V-Source Checks (Model 487 Only)
step Item/Component Required Condition Remarks
1 V-Source Contiols
Standby operation OO.oOOV setting (5OV range) lnitlal conditions
2 Reference point Connect DMM LO on scope LO to V-SOURCE
Au voltages referenced to V-Source
OUTPUTLO common.
3 UlcQ, pin 1
+15v, rt5% +15vB supply
4 um, pin 3 -15v, 6%
-15VB supply
i
u102, pin 1 +5v, f5%
+5vB supply
VRlCO, anode +8ooV, k15% +SOoVB supply
7 V-Source Controls Set to lO.CMW (5OV range) Place in OPERATE
Source +lOV on 50V range to open
output terminals
8 u151, pin 5 +1.54v
DAC output
9 UN!, pin 6 -1.54v Inverting Xl buffer output
10 UllO, pin 6 -7v High impedance amplifier output
11 QlOl, gate
+13v Power PET
12 QlO5, source -3v
Power PET
13 V-Source output +10.000V*14mV Voltage source output
14 V-Source Controls Set to OlO.OOV (5OOV range). Place in OPERATE Source +lOV on 5COV range
15 u151, pin 5 +153mv DAC output
16 U143, pin 6 -153mv Inverting Xl buffer output
17 UllO, pin 6 -7v High impedance amplifier output
18 QlOl, gate c13v Power FET
19 QlO5, source -3V
Power PET
20 v-source output
+lO.cnNV, f55mv
Voltage source output
21 - Short output, set I-Limit to 2.5mA
-
22 4103, source +0.7v Power PET
23 -
set I-Limit to 25pA
-
24 U119, pin 6 -9v
25&A I-Limit control
25 VRlO6,cathode -3v Line voltage protection
26 QlOl, gate +3v Power FET
27 QlO5, source -3v Power PET
28 V-Source
Controls
Place in Standby
7-18