Hammond L series User Manual

thru
-9). All necessary
DC
supply
voltages
for
the
rhythm
unit
are supplied
by this
chassis.
The
output
voltages
are 30
V DC,
15
V DC, and
5.5 V
DC. The 5.5
V
output
is
not used
in
the
Model
L-
100-1
organ.
120
V
AC
50/60
Hz
is
supplied to
the
power
transformer
from an
external source.
The
secondary
AC voltage is 40
V AC,
which is
then
rectified
by
the
full wave
bridge
of diodes
D
1
00,
D 1
0
1
,
D
1
02
and
D103. This
DC voltage is
then
filtered
by
the
combination
of
RlOl,
R103,
ClOOA,
CI 01
and
appUed across the 30
V DC
Zener
diode
D104.
The
30
V DC is the supply
voltage
for the
amplifier
stages
Q106,
Q107
and
Ql 08 on the
rhythm
PWB
and
the
reference
voltage for
the 1 5
V
DC and
5.5 V DC suppUes.
The 30 V DC
is
supplied
to
the voltage
divider of
R107
&
R108
and
fed to
the voltage regulators Ql
00 &
Ql
02,
the output
of
which is the
1
5 V
DC which
is
used to supply all
other
circuits
on the
rhythm device.
The 30
V
DC is also supplied
to the
voltage
divider
R106
&
R105, and
fed
to
the
2-
emitter
follower QlOl
,
the emitter
output
of
which is
5.5
V
DC.
QlOl
is used as a
voltage
regulator and in conjunction
with
ClOOB provides the
filtering
for
the 5.5
VDC.
2-17.
PUSH
BUTTON CIRCUITS (See
Figure
5-6).
One side
of each push button is connected
thru R200,
2.2K ohm
resistor
to
the
15
V
DC
supply.
The 1
5 V DC
is
available to the
push buttons at
all times, and
if one
is
de-
pressed
at
any time,
that
particular voice
will
appear at the output.
When any
of
the
push buttons
is
depressed, that button
apphes 1
5 V DC
to
the base input
of
a
phase shift oscillator.
As
an example, if
the
BLOCK
push button
is depressed, 1 5
V DC
is
apphed to
the
junction of RIOOB and capacitor ClOOB.
This signal
is
differentiated by
CI
OOB and
the
resulting
pulse
is
fed thru DIOOB
and
Rl 05 to the
base
of Ql
OOB, turning
it
on.
This signal
is
fed
back to
the
base,
inverted
by
the phase shift network
C103B, C102B,
C104B, R106B,
and
R107B,
and
will
be
regenerative
for
a
period
of
time
determined
by
RIOOB,
ClOOB, and RIO IB.
The
decay-
time
of
the
collector output depends
upon
the values
of ClOlB,
R105B
and
R102B.
2
The
output
is
coupled through capacitor
C105B,
resistor
R104B, and
capacitor
CI 20
to
the base
of
ampUfier
stage
Ql
07,
and
after
amplification
by
Q
107
and
Q108,
it
is
connected to
R203, the
volume control.
TOM-TOM,
BONGO,
and
CLAVES
are
similar
in
operation.
The
frequencies
of
the
oscillators
are determined by
the
values
of
the
components in
the
phase shift
network.
When
the
BRUSH push
button is
depressed,
+
1
5 V DC
is
suppUed
to
the junction of
Rl 16 and
CI 1
1
,
and this
supphes
bias
through
D102 to
the base
of
Q103,
tuming
"on"
the
one shot
multi-vibrator stage,
Q103
and
Q104
for
one complete
cycle.
The
Brush Gate
transistor
Q
105 is
turned
"on"
for
a
period
determined
by
CI 13 and
R120
of the
multi-vibrator stage.
This
apphes
positive
bias
through R123, D104,
R124
to
base
of
Q105,
turning on
Q105
and
allowing
white
noise to
appear
on col-
lector
of Ql
05,
tuned by
CI
15 and
LI
01,
and
this
signal
is
then
routed through
CI
1
7
and
output level
control
R126
and
R127
to
hiss
amplifier
Q106.
LOWER
MANUAL KEYING CIRCUITS (See
Figure
5-6).
-
The lower manual
buss
line
is
connected
through
CI 24
and the
base
of
Q109,
which
is a
pulse
ampUfier
stage.
Re-
sistor
R147
provides base bias
to
the
stage,
so
that with
no key depressed,
the collector
is
at
approximately
4.5
V
DC. CI
24
and
R145 is a
differentiating
network
which
puts
a
pulse on the base
of
Q109.
This
pulse
is
amphfied
by
Q109,
and instanta-
neously the
collector of
Q
109 rises
from
4.5 V DC to
approximately
1 1
V DC This
change
is
routed through
R149
to
the
base
of Ql
10,
which at
an emitter
voltage
of
5.5
V and base
bias
of 4.5
V
was
"off".
With
1
1 V on
its base,
QUO turns
"on", and
its
collector, which was
at
1
5
V
drops to
5.5 V. This
change is
coupled
through
CI
26
and
R153 to
the base
of Qlll,aPNP
which
has
been
biased
"off" through
R152
and
R153. The change in bias turns "on"
QUI
and the
collector has an
instanta-
neous
output
of
+
1 5
V DC of
about 2
milliseconds
duration. This
trigger pulse
is
defined as
the
lower manual
trigger pulse.
The
pulse
is
routed
through
whichever
LOWER
tabs
are "on" to
trigger
the
selected
voices.
Output is
obtained
as
described
in
Paragraph
2—17.
19.
PEDAL KEYING
CIRCUIT (See
Figure
5-B).
-
A signal
of
approximately
75
mV

Hammond L series Specifications

General

Brand	Hammond
Model	L series
Category	Musical Instrument
Language	English