In some cases it beneficial to have a circuit that has an odd number of inputs and for the output to take the state of the majority of the inputs. With a 5-input majority circuit, for example, the output is high if any 3 or 4 or all 5 inputs are high.
TYPES OF INDUCTOR
There are many kinds of components that posses self-inductance. Such as, Solenoid coils, the loudspeakers and other few other devices that include a coil. Even the leads of a capacitor, resistor or transistor, though they do not have coil, possess few self-inductance at radio frequencies. In these cases the Inductance is very low and is thus ignorable, or may cause problems.
Inductance is a useful attribute of certain other type of components. These include the following:
Chokes:
The chokes are effectively applied for blocking high-frequency signals so that they cannot pass through from one part of a circuit to another. Low-frequency signals or DC voltage levels has the ability to pass through. Large chokes look like transformers, but contain only one coil. Small chokes has beads or collars that are composed of ferrite, and are threaded on to the wire that is carrying the high frequency signals.
HALF ADDER
HALF ADDER
Arithmetical operations are often an essential function of logic circuits. This truth table describes the simplest possible operation, adding two 1-bit binary numbers A and B:
The half adder circuit generally needs two outputs, these inputs are sum (S) and the carry-out (Co). The logic of each of these inputs is normally determined separately. Comparing the output values in the S column with those in the truth tables tells us that the operation for summing is equivalent to exclusive-OR. The operation for producing the carry-out digit is AND. The complete half adder needs only two gates. If required, the half adder can be built entirely from NAND gates by using an exclusive-OR circuit to produce S. The exclusive-OR circuit
FULL ADDER
The half adder is called half because it is in-complete. It cannot accept a carry-in Ci from a previous stage of the addition. The truth table related to the full adder is shown below. The addition of A and B is shown by the first four lines when the carry-in is zero. The values of A, B, S and Co are identical with the values contained in the half adder table. The last four lines of the table show the addition when carry-in is 1.
DATA-TYPE FLIP-FLOP
Diagtam 12. 10 show the symbol used for the data-type (or D-type) flip-flop and the action of ehis flip flop is plotted in the graphs. For the purpose of clocked mode operation like this, the Set input (S) and Reset input (R) are held low. Buy there are few kinds of D-type flip-flop that do not have the R input.
12
The graphs that are shown below are drawn on the basis of a simulator, modelling a 74LS74 D-type flip-flop. This clock is running at the frequency of 10 MHz and the time scale measures in nanoseconds. When The graph lowest it shows the output Q. The simulator is stepped manually so that it enables you to make the data input high or low when we desire.
TOGGLE FLIP-FLOP
Toggle flip-flop is represented by T-type-flip-flop. The output of this type of flip-flop changes every time the clock goes high. T-type-flip-flops are not manufactured in this way. It is easier to create one from a D-type flip-flop. This is done by connecting the Q output to the D input. See the following diagrams.
SIGNAL-TO-NOISE RATIO
We can express the amount of noise present in a signal in many different ways. We need not usually the absolute power of the noise, but the power of the noise relative to the power of the signal itself is important. Keeping this reason in view, one of the most commonly used ways of expressing the amount of noise is the signal-to- noise power ratio. A ratio of two powers is most conveniently stated on the decibel scale. As the power is directly proportional to voltage squared, the signal-to- noise ratio is defined as:
In equation shown above, vs is the rms signal voltage and vn is the rms noise voltage. The equation has the standard form that is used for expressing a ratio of powers in decibels.
