Service manual

2
OTP
“One
Time
Programmable”
A type of (E)prom which can not be
erased.
P.C.
“Personal
Computer”
PD
“Phase
Detector”
This PLL pin provides a pulsed output
whose
average
voltage, after
filtering
and
smoothing, controls the frequency of the
VCO.
PGM
ProGraM”
A
suitable
voltage
pulse on this Eprom
pin will enter into an Eprom the code on
its output data pins,
according
to the
location
code on its input or address pins.
PLL
“Phase
Locked
Loop”
In this context, refers to an
Integrated
Circuit
which controls the frequency of
an
oscillator
according
to the "
Nt'
code
on its inputs.
Quartz
A
mineral
which is
transparent
to
light
and, more
importantly,
to
ultra-violet
light.
Regulator
A
device
or
circuit
which produces a
constant
voltage
output even if the input
voltage
varies.
Skip
...
see
“A”
channel.
Software
Refers to a microprocessor or
computer
program, rather than the
circuit
components themselves.
Switch
codes
The binary outputs of a
channel
switch.
•UV
Ultra
Violet
light
which is
invisible
to the
human eye and can be harmful.
Vcc
The IC pin which requires a
positive
supply voltage.
Vdd
The IC pin which is
connected
to
ground.
VCO
"Voltage
Controlled
Oscillator"
Vpp
The IC pin which must be
connect
ed to a
specified
voltage
in order to allow
programrning of the device.
Zener
A type of diode which produces a
specific
voltage
when current flows through it in
the reverse direction, that is, with the
anode more
negative
than the cathode.