Oversættelse af Tekniske Tekster - OpenArchive@CBS
Oversættelse af Tekniske Tekster - OpenArchive@CBS
Oversættelse af Tekniske Tekster - OpenArchive@CBS
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V To modulate [modulation]<br />
Modulate ses benyttet med to indholdssider, den ene svarer til control i betydningen at styre. I<br />
teksteksemplerne nedenfor kan vi tænke på en spænding eller strøm fra fx en mikrofon der<br />
tilføres styreelektroden i en transistor og får en kr<strong>af</strong>tigere strøm til at variere i takt med<br />
lydbølgerne der påvirker mikrofonen:<br />
Transistor. A multielectrode semiconductor device in which the current flowing<br />
between two specified electrodes is modulated by the voltage or current applied to<br />
one or more specified electrodes (Illingworth 91: 493)<br />
Field-effect transistor (FET). A unipolar multielectrode semiconductor device in<br />
which current flows through a narrow conducting channel between two electrodes and<br />
is modulated by an electric field applied at a third electrode (Young 88:186)<br />
Der ses tilsvarende tekster, hvor control erstatter modulate:<br />
By changing the very small current in the base of the transistor, a much larger current<br />
flowing in the collector and emitter may be controlled Britannica Student<br />
Encyclopedia. 2004. Encyclopædia Britannica Online. 22.10.04<br />
In a field-effect transistor (FET) the currents are controlled [styres] by an applied<br />
electric field, generated by a voltage at a control electrode (the gate)<br />
AccessScience@McGraw-Hill, http://www.accessscience.com 22.10.04<br />
I den typiske betydning <strong>af</strong> modulate påtrykkes den forstærkede spænding fra fx mikrofonen<br />
en højfrekvent bærebølge (’radiobølger’)for at signalet kan transmitteres:<br />
Modulation. In general, the alteration or modification of an electronic or acoustic<br />
parameter by another. In particular, the process of varying one electronic signal, called<br />
the carrier, according to the pattern provided by another signal, as when an<br />
audiofrequency signal is impressed onto a higher-frequency carrier wave for radio<br />
transmission (Illingworth 91: 305)<br />
Første del <strong>af</strong> definitionen beskriver hvordan én fysisk størrrelse (fx spænding eller strøm)<br />
styrer en anden og her er det mere almindeligt at se vary, control eller regulate. Om control<br />
grid kan man fx se i praktiske tekster at a signal is impressed to regulate/control the plate<br />
current.<br />
Anden del <strong>af</strong> definitionen beskriver den typiske forekomst <strong>af</strong> modulation: en bærebølge<br />
moduleres så den kommer til at indeholde information:<br />
FM receiver. A radio or television receiver that detects frequency-modulated signals<br />
(Young 88: 201)<br />
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