1.
To convert a Boolean expression to a logic diagram, the technician must first identify the
overall type of circuit associated with the expression. This is necessary for two reasons:
(1) to determine where the expression must first be separated and (2) to determine which
logic symbol must first be drawn to represent the final output Boolean expression
correctly.
To convert a Boolean expression to a logic diagram, the first step for the technician is to
__________________ the __________________ __________________
of circuit associated with the expression.
identify
overall type
2.
To construct a logic diagram from a Boolean expression, begin drawing at the right and
work left. If letters in the expression are grouped (by parentheses, brackets, braces,
vincula, etc.), first, separate the group from other groups or letters. For example, Boolean
expression (A+B)(C+D) indicates that the quantity (A+B) grouped together by
parentheses must first be separated from the other group (C+D). Examination of the
expression reveals that it is a two-input AND gate with inputs (A+B) and (C+D). If the
letter X were substituted for the quantity (A+B) and the letter Y were substituted for the
quantity (C+D), the expression would then be represented by XY, a more obvious
expression for a two-input AND gate. Substituting single letters for grouped quantities is
an aid in determining the overall type of circuit the expression represents.
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IT 0343
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