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Diodes I
here. We needn’t know any more about it here because we’re
only concerned with the practical aspects at the moment;
and all we need to remember is that a forward biased diode
conducts, allowing current to flow, while a reverse biased
diode doesn’t.
What we do need to consider in more detail; however, is the
value of the current flowing, and the small, but nevertheless
apparent, voltage which occurs across the diode, when a diode
is forward biased (the voltage we said earlier we needn’t
then worry about). The following experiment will show how
the current and the voltage are related.
Figure 6.7 shows the circuit you have to build. You’ll see that
two basic measurements need to be taken with your meter.
The first measurement is the voltage across the forward biased
diode, the second measurement is the current through
it. Each measurement needs to be taken a number of times
as the preset is varied in an organised way. Table 6.1, which
is half complete, is for you to record your results, and Figure
6.8 is a blank graph for you to plot the results into a curve.
Do the experiment the following way:
Figure 6.7
A circuit to test the operation of a forward biased diode
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