Page 853 - Mechanical Engineers' Handbook (Volume 2)
P. 853

844   Mechatronics

           2.3 Other Common Op Amp Circuits
                          Some other useful op amp circuits are described in Fig. 29 (page 843).



           3 BINARY NUMBERS
                          Computers and digital electronics used in mechatronic systems are described by binary ar-
                          ithmetic. Therefore, it is important to understand binary numbers to fully understand the
                          function of computers. First, consider a base-10 number as in standard mathematics. Base-
                          10 numbers have 10 possible digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). Consider a number such as
                          234. Here the 4 represents the 1’s digit, the 3 represents the 10’s digit, and the 2 represents
                          the 100’s digit. The number 234 represents four 1’s and three 10’s and two 100’s(4 * 1
                          3 * 10   2 * 100   234). The value of each digit increases by a factor of 10 as you move
                          to the left and decreases by a factor of 10 as you move to the right. Consider a number such
                          as 234:
                                                       2    3    4
                                                                        1’s digit
                                                                   10’s digit
                                                                  100’s digit

                             4 represents the sum of nine 1’s
                             3 represents the sum of seven 10’s
                             2 represents the sum of one 100
                             Now, consider a base-2 number, or a binary number. Base-2 numbers have two possible
                          digits (0, 1). Again, consider the number 234. With binary numbers the value of each digit
                          increases by a factor of 2 as you move to the left and decreases by a factor of 2 as you
                          move to the right. To write this number as a binary number requires zero 1’s and one 2’s
                          and zero 4’s and one 8’s and zero 16’s and one 32’s and one 64’s and one 128’s (234
                          11101010   0 * 1   1 * 3   0 * 4   1 * 8   0 * 16   1 * 32   1 * 64   1 * 128):
                                              Binary base 2: two possible digits (0, 1)

                                                       234 	 11101010

                                                         0      1’s
                                                         1      2’s
                                                         0      4’s
                                                         1      8’s
                                                         0     16’s
                                                         1     32’s
                                                         1     64’s
                                                         1    128’s


           3.1  Binary Numbers of Different Size
                          Each digit in a binary number (either a 0 or a 1) is called a bit—‘‘binary digit.’’ A nibble
                          is a group of 4 bits, a byte is a group of 8 bits, a word is a group of 16 bits, and a double
                          word (dword) is a group of 32 bits. Each bit is numbered starting with zero and moving to
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