18WuD2x

self-excited oscillator • self-sustained oscillations 617
such as the capacitance and inductance in a tank
circuit. Compare CRYSTAL OSCILLATOR, FORK
OSCILLATOR, HUMMER, and MAGNETOSTRIC-
TION OSCILLATOR.
self-excited oscillator
+
Output
self-focus picture tube A television picture tube in
which the electron gun has an automatic, electrostatic
focusing arrangement.
self-generating photocell See PHOTOVOLTAIC
CELL.
self-generating transducer A voltage-producing
transducer, such as a piezoelectric pickup or dynamic
microphone.
self-healing capacitor A capacitor, such as a wet
electrolytic unit, in which the dielectric is restored
to its normal condition after a high-voltage
breakdown.
self-heated thermocouple A thermocouple in
which the passage of an applied current produces
the heat necessary for the activation of the thermocouple.
self-heating thermistor A thermistor heated to
above ambient temperature by the current passing
through it. Also called DIRECTLY HEATED
THERMISTOR. Compare INDIRECTLY HEATED
THERMISTOR.
self impedance The effective or measured impedance
at a circuit point.
self-inductance 1. The inductance of an inductor.
2. The inherent internal inductance of a device
other than an inductor.
self-induction Induction that occurs in a single
circuit. An instance is the generation of an opposing
voltage across a coil by an alternating current
flowing through it. Compare INDUCTION.
Also see INDUCTANCE.
self-latching relay A relay that remains in the
state that it has been switched (i.e., locked open
or closed) until a subsequent signal is received.
self-modulated oscillator A circuit, such as a
blocking oscillator, in which oscillation occurs
simultaneously at two frequencies, one modulating
the other.
self-organizing Pertaining to a computer or system
that can change the arrangement of data files
for particular purposes.
self-powered device A device that requires no external
source of power (i.e., it is equipped with a
self-contained battery or a generator).
self-pulsing blocking oscillator A blocking oscillator
that produces a train of radio-frequency
pulses. Compare SINGLE-SWING BLOCKING OS-
CILLATOR.
self-quenching detector A super-regenerative detector
(see SUPER-REGENERATIVE CIRCUIT) in
which the low-frequency quenching voltage is
supplied by the regenerative detector itself. Also
see QUENCHING ACTION and QUENCH OSCIL-
LATOR. Compare SEPARATELY QUENCHED DE-
TECTOR.
self-quenching oscillator A circuit, such as a
blocking oscillator, in which oscillation is periodically
switched off automatically, resulting in a
self-interrupted wave train.
self-rectifying vibrator A vibrator-type power
supply in which one vibrator reed chops the direct-current
input to the primary winding of the
transformer, and a second vibrator reed rectifies
the alternating-current output delivered by the
secondary winding. Also see VIBRATOR RECTI-
FIER.
self-rectifying X-ray tube An X-ray tube operated
with alternating-current anode voltage.
self-regulation The ability of a circuit or device to
control its output automatically, according to
some predetermined plan, by using output error
to correct operation or to vary the input.
self reset 1. The action of a circuit breaker to reapply
power after a certain elapsed time. 2. The action
of any device, returning a circuit or system to
normal automatically.
self-resetting loop In a computer program, a loop
in which instructions cause locations used in the
loop to assume their condition prior to the loop’s
execution.
self-resistance The inherent internal resistance of
a device other than a resistor.
self-resonant frequency The frequency at which a
device will resonate naturally (without external
tuning). Thus, an inductor will self-resonate with
its distributed capacitance; similarly, a capacitor
will resonate with its stray inductance.
self-saturation In a magnetic amplifier, saturation
resulting from rectification of the saturablereactor
output current.
self-starting motor An alternating-current motor
that starts running as soon as voltage is applied
(i.e., no external mechanical force is needed). Also
see SHADING COIL.
self-sustained oscillations Oscillations maintained
by means of positive feedback (inductive
or capacitive) from the output to the input
of a circuit. See, for example, SELF-EXCITED
OSCILLATOR.