Output - Casio CZ-1 Service Manual And Spare Parts List

21-3.
Thrte-Phase
LFO (Low
Frequency
Oscillator)
The
left
figure
shows
three inverters serially
connected.
If
LOW
level
input enters the
circuit,
the output
becomes
HIGH
level.
Because of the transfer characteristic
of the
inverter*
the inverted input voltage appears
on
the
output
with a time
lag.
Hence, the circuit oscilates
and
the oscillation
frequency
is
determined by
the
time
lag.
The
following
shows
the actual circuit
of the Three-Phase
LFO. The
time
lag
is
controlled
by
the parallel
connected
capacitor
and the
resistors.
Model CZ-1 employs
two LFOs whose
oscillation
frequencies are
0.56
Hz
and 7.14Hz.
The output
differs
120 degrees
in
phase.
i\
—
|
II
—
I
|
lr
* *
it
OSC1
OSC2 OSC3
OSC3
'120"
120*
Both
0.56
Hz
and 7.14
Hz
triangle
waveforms
are
mixed
to
give variational delays of the
sound
in
the
BBO.
7.14Hz
3-phatt
LFO
18K
>
ToVCO
0.56HI
3-PtiM*
LFO
AAA
Ti.e
0.56
Hz
and 7.14
Hz
waveforms
are
mixed
in
the
ratio of 10:1
as
they pass through
18Kohm
and
180Kohm
resistors, respectively.
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