Circuit
Description
—Type 3B5
Fig.
3-28. Operating Mede Power logic block diagram.
pressed,
SW914
raises
the
base
of
Q915
positive
enough
to
turn
it
on
and
its
collector
goes
negative.
Q905
is
turned off
through
D901
and
Q915
controls
the
circuit (except
in
External
Mode; see
External
Mode Control
discussion).
Changing
the
MANUAL
TIME/DIV
switch
returns
the
unit to
the Manual
Mode of
operation
when
in
the
Seek
Mode.
The
base
level
of
Q905
is
established
by
a
divider
to
ground
through
the
MANUAL
TIME/DIV
switch
(note
that
only
part
of
this
switch
is shown
on
this
diagram;
see
diagram
5
for
complete
switch).
As
this
switch
is
rotated
between
steps,
the
ground
connection
for
the
divider
is
momentarily
opened.
The
base
of
Q905
goes
negative
and
it
shuts
off.
Then,
Q915
comes
on
and
locks
off
Q905
to
establish
Manual
Mode
operation.
Divider
R91
1
-R912-R913 holds
the base
of
Q915
slightly
more
positive
than
the
base
of
Q905
to
return
the
unit
to
Manual
Mode
operation
when
the
external
mode
command
is
disconnected.
Seek
Mode
Control
Fig.
3-30
shows
circuit
conditions for
the
Seek
Mode
of
operation.
In
this
mode
of
operation,
Q905
determines the
output
from
this
circuit.
Q905
is
forward
biased
by
the
level
at its
base
established
by
divider
R901-R902-R903.
This
bias
level
is
interrupted
to
return
the
unit
to Manual
Mode
opera
tion
when
the
MANUAL
TIME/DIV
switch
is
rotated
(see
Man
ual
Mode
Control
discussion).
The
collector
current
of
Q905
flows
through
B905
and
the
SEEK
pushbutton
lights
up.
This
bulb
drops
about
six
volts
of
the
—
12-volt level
at
the
col
lector
of
Q905
to provide
current
to
the
—
6-volt
output line
Current
also
flows
through
D909
to
provide
Seek/Manual
Power
output
and
through
D91
1
to
lock Q915
off.
With
Q915
off,
K915-1
connects
—12.2
volts
to
the
Seek/External
Power
output.
The
Seek
Mode
of
operation
can
be
obtained
from four
sources;
front-panel SEEK
button,
remote
seek
command
through
the
front-panel
PROGRAM
connector,
seek command
from
a
remote-seeking probe
through
an
automatic/program-
mable
amplifier
unit
and
remote
seek
command
through
the
amplifier
unit program connector.
When
the
Type
3B5
front-panel SEEK button is pressed,
SW604
raises
the
base
of
Q905
positive
enough
to
turn
it
on
and
its
collector
goes
negative.
Q915
is
turned
off
through
D91
1
and
Q905
con
trols
the
circuit
(except
in
External
Mode;
see
External
Mode
Control
discussion).
The
seek
command
from
the
amplifier
unit or
the
remote
seek
command
similarly
raises
the
base
level
of Q905
to
allow
it
to
come
into
conduction.
External
Mode
Control
External
Mode
operation
is
provided
only
when
the
EXT
button
is
held
depressed
or
when
an
external
mode
com
mand
is
applied
through
the
PROGRAM
connector. The
circuit
is
connected so
that
this
stage
over-rides
the
other
two
control
stages.
Fig. 3-31
shows
circuit
conditions
for
External
Mode
operation.
Q925
is
on
when
the base
is
held
positive enough
to
forward
bias
the
transistor
either
by
holding
the
EXT
button
depressed or
by
external
mode
com
mand
through
terminal
21
of
J30.
When
Q925
is
on,
col
Содержание 3B5
Страница 4: ...Fig 1 1 Type 3B5 Automatic Programmable Time Base unit Type 3B5...
Страница 15: ...Operating Instructions Type 3B5 TYPE 3B5 CONTROL SET UP CHART Fig 2 2 Control set up chart 2 7...
Страница 48: ...CO I o Fig 3 13 Delay and Timing Circuit logic block diagram Circuit Description Type 3B5...
Страница 61: ...GO i GO GO Fig 3 22 Seek Ciicuit Logic block diagram Circuit Description Type 3B5...
Страница 70: ...u k KJ Fig 3 29 Circuit conditions for Manual Mode operation Circuit Description Type 3B5...
Страница 71: ...w K w Fig 3 30 Circuit conditions for Seek Mode operation Circuit Description Type 3B5...
Страница 72: ...w I u U Fig 3 31 Circuit condition for External Mode operation Circuit Description Type 3B5...
Страница 88: ...Maintenance Type 3B5 Fig 4 9 Location of components on Logic Card 4 14...
Страница 89: ...u Oi Fig 4 10 Location of components on Counter Card Maintenance Type 3B5...
Страница 92: ...NOTES I...
Страница 104: ...NOTES...
Страница 106: ...Calibration Type 3B5 Fig 6 1 Recommended calibration equipment...
Страница 160: ......
Страница 176: ...J400 RtADOUT BOARD 3B5 PLUG IN A READOUT...
Страница 182: ...397 R E A D O U T B O A R D 10 6b READOUT BOARD...
Страница 184: ...FIG 1 FRONT SWITCHES TYPE 3B5 AUTOMATIC PROGRAMMABLE TIME BASE...
Страница 185: ...FIG 2 CHASSIS REAR 3 GS to TYPE 3B5 AUTOMATIC PROGRAMMABLE TIME BASE...
Страница 186: ...OPTIONAL ACCESSORIES...