HP 8112A, Operating, Programming And Servicing Manual

Page: 223 / 406

Note
Slope Generator
Width vernier current can be checked by measuring the voltage
across R245.
7. Set HP 81 12A PE R to 20 ms
8. Check signal levels against Table 10.3- 1 5
Table 1 0.3-15. Width Generator Signal Levels
WID Setting Voltage across R245
1 ms +0.125 v
5
ms
+0.004 v
9.99
ms
-0.02 v
1 .
Set the HP 8112A to R CL 0 and press the � key:
2. Check the input signal from the width generator at pin 1 of U301
against Figure 10.3- 16
3.
Check the ramp current input at pins 9 and
12
of
U301
against
Figure 10.3-16
4 .
Check the signals being sent to the shaper IC (waveforms at TPl ,
TP4 and pin
21 of U301 ) against Figure 10.3-16.
P i n s 9 & 1 2
P 1 n 1
TP 4
TP 5
+ l
. B V
OV
l
ms
----�1
+0.
1 4 V
+0.
2 5 V
+0.
1 4 V
-0
-
0
.
3 9 V
I
I
I
I
I
r100us
I
I
I
I
Figure 1 0.3-1 6. Slope Generator Input and Output signals
Servicing the Timing and 1 0.3-2 1
Slope Generators