Wiring Symbols:
There are many different representations for basic wiring symbols,
and these are the most common. The conventions I use for wires
crossing and joining are marked with a star (*) - the others are a
small sample of those in common use, but are fairly representative.
Many can be worked out from their position in the circuit diagram
(schematic).
Fig - 1 : Wiring Symbols
Units :
The commonly accepted units in electronics are metric. In
accordance with the SI (System International) metric specifications,
any basic unit (such as an Ohm or Farad) will be graded or
sub-graded in units of 1,000 - this gives the following diagram.:
The abbreviations and case are important - "m" is quite clearly
different from "M". In general, values smaller than unity use lower
case, and those greater than unity use upper case. "k" is clearly
an exception to this. There are others that go above and below
those shown, but it is unlikely you will encounter them. Even Giga
and Tera are unusual in electronics (except for determining the size
hard drive needed to install a Microsoft application.