Philips SCOPEMETER PM93 Service Manual page 35

CIRCUIT DESCRIPTIONS
r - - - - - - - - - - - - - - - - - - - - - - - -
I
I
I
ANALOG CONTROL
CIRCUIT
I
I
I I I
I I I
CONNECTORS
I
I
I I
I
I
t
GREY BNC
I
(CHANNEL B)
CHANNEL B
0
.
ATTENUATOR
I
I
(+
PROTECT JON)
I :
I
1
I I
I I
l
I
1
t
RED BNC
ANALOG ASIC
(CHANNEL A)
I
CHANNEL A
0
ATTENUATOR
I
(+
PROTECT) ON)
-AMPLIFICATION
-CHANNEL SELECTION
-TRIGGER SELECTION
-DELTA-T CIRCUIT
I
I
mV
I
I
DIODE
L
I
Ohm
-
- 1 -
-
- - - ..
-
-~
- -
-
- - - - - - - -
.~
-
+
RED
,...
EXTERNAL (BANANA)
....,
BANANA
INPUT/OUTPUT
GENERATOR
,...
--'"
CIRCUIT
....,
V
BLACK
(+
PROTECT ION)
- - - - - - - - -
-
- - - - - - -
-
---
ON/OFF
CIRCUIT
BATTERY
SENSE
CIRCUIT
KEYPAD
OPTICALLY
COUPLED
RS-232-C
TRANSCEIVER
v
KEYPAD
DRIVERS
-
Figure 3. 1 Overall Functional Block Diagram ScopeMeter
RESET
CI RCUIT
v
MICRO-
PROCESSOR
I
-
A
DATA
ADDRESS
t