Controls And Their Functions - Philips Pm 3342 Manual

13
Controls and their functions
(Fig. 2)
O
MODE selector SKS
~ ~ ~ i ~ ~
~ ~ i i i i
~~
~~` ~~`
~ `~
~~
Trigger mode selector SK6
Input circuit
The working mode of the unit can be selected with the
six-position mode selector.
channel A is switched in,
channel B is out of action
channel B is switched in,
channel A is out of action
CHOPPED both channels are switched in. The volt-
ages applied to sockets A and B are elec-
tronically switched. The frequency in
which the channels are switched, can be
adjusted to 20 kc/s or 500 kc/s with switch
SK 11, located on aprinted-wiring board
at the right-hand side of the unit.
"ALTER-
channels A and B are alternately dis-
NATE" played.
Switching occurs during the flyback of
the time-base voltage.
"ADDED"
the voltages at the output of both ampli-
fiers Aand Bare added. Dependent on
the position of the polarity switches, the
sum or the difference of the input signals
is applied to the Y-amplifier of the basic
oscilloscope.
"EXT.
The channels are switched with a voltage,
CHOPPED the frequency of which is equal to that of
BU3"
the voltage applied to socket "EXT.
CHOPPED".
TRIGG A
The trigger signal is equal to the voltage
applied to socket A.
B
The trigger signal is equal to the voltage
applied to socket B.
When the MODE selector is in position
"ADDED", the "TRIGG." switch is out
of action. In that case the trigger signal is
taken from the output amplifier.
AC-DC
Via this switch, the input socket is con-
switch
nected to the V/cm switch. In the DC-
(SK3; SK9) position, the entire input signal is fed to
the V/cm switch; in the AC-position, the
DC-component is blocked.