General qualifying and supplementary symbols Earth
Direct current or
steady voltage
Alternating: general symbol
Indicates suitability for
use on either direct or
alternating supply
Variability: general symbol
When it is necessary to
distinguish between
earth connections, the
symbols may be
annotated or numbered.
Example: signal earth
Frame or chassis not
necessarily earthed
I
Signal
/77I7
Pre-set adjustment
Inherent non-linear
variability
Positive polarity
Negative polarity
+
Mechanical coupling:
general symbol
Example
Impedence
Rectifier
Signal lamp:
general symbol
—ι—ζ—t—
Unclassified symbols
Primar ...
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