Page 41 - Bebop to The Boolean Boogie An Unconventional Guide to Electronics Fundamentals, Components, and Processes

22 ChapterThree

;"' t

I I
'I

/ I
I/

I
I
I )Time
0 Amps
TO '5TABLE
(a) Voltage characteristic of yND (b) Current flowing in the circuit

Figure 3-1 5. Voltage and current characteristics of resistor-
inductor-switch circuit

depending on its physical characteristics (size, material, etc.). Similarly, an
inductor has a natural resonant frequency depending on the diameter of the
rod, the material used to form the rod, the number of coils, etc. For this reason,
inductors may form part of the tuning circuits used in radios (they also have
many other uses that we won't go into here).
Once a circuit has reached a steady-state condition where nothing is
changing, any capacitors act like OPEN (OFF) switches and any inductors act
like simple pieces of wire. The effects of these components only come into play
when signals are transitioning between different values.

Unit Qualifiers

Engineers often work with very large or very small values of voltage,
current, resistance, capacitance, and inductance. As an alternative to writing
endless zeros, electrical quantities can be annotated with the qualifiers given
in Table 3-1. For example, 15 MQ14 (15 megaohms) means fifteen million
ohms, 4 mA (4 milliamps) means four thousandths of an amp, and 20 fF

(20 ferntofarads) means a very small capacitance indeed.

14 Remember that the Greek letter omega ''CY is used to represent resistance.