Definition: An open-loop system is a type of control system in which the output of the system depends on the input but the input or the controller is independent of the output of the system. These systems do not contain any feedback loop and thus are also known as non-feedback system. In open-loop systems, the output is neither measured nor fed back to the input for further consideration. Open-loop System In our previous article, we have discussed about control system. We know that a … [Read more...] about Open-loop Control System
Control System
Definition: A combination of various elements connected as a unit to direct or regulate itself or any other system in order to provide a specific output is known as a Control system. We know controlling is basically known as the act of regulating or directing. So control system is used to direct the functioning of a physical system to carry out the desired objective. For example, from a television system, refrigerator, air conditioner, to automobiles and satellites everything needs a … [Read more...] about Control System
Programmable Logic Array (PLA)
Definition: Programmable Logic Array, abbreviated as PLA is a programmable logic device having programmable AND gates and OR gates. These devices are basically programmed to implement the Boolean functions. The fundamental components of PLAs are input buffer, programmable AND gate matrix and programmable OR gate matrix. PLA allows the implementation of any random boolean function present in SOP form using programmable technique. Components of PLA Input Buffer: Basically buffers at the … [Read more...] about Programmable Logic Array (PLA)
Shift Register
Definition: A shift register is a sequential logic circuit that acts as a unit to store and transfer binary data. Basically shift registers are bidirectional FIFO circuit, that shifts every single bit of the data present in its input towards its output on each clock pulse. We know registers are the circuits constructed using flip-flops for storing binary data. One-bit of data is stored by each flip-flop at a time. So, the storage of multiple bits of data requires multiple flip-flops. Thus … [Read more...] about Shift Register
Freewheeling (Flyback) Diode
Definition: Freewheeling diode is used to protect the circuit from unusual damage caused due to abrupt reduction in the current flowing through the circuit. It is also known as Flyback diode and forms connection across the inductor to remove Flyback voltage generated across it. Freewheeling diodes are also known as kickback diode, clamp diodes, commutating diodes, suppression diodes, or snubber diode etc. Here in this article, we will discuss the factors responsible for the need of such … [Read more...] about Freewheeling (Flyback) Diode
Digital Comparator – Magnitude and Identity Comparator
Definition: A Digital Comparator is a combinational logic circuit that is used for comparison of two binary values. Basically it generates the desired signal (either low or high) at the output when compares two digital values provided at its input. We all know that combinational circuits (like adder and subtractor) produce addition and subtraction of binary values present at the input terminals. But, along with addition and subtraction, some applications require a comparison of two values … [Read more...] about Digital Comparator – Magnitude and Identity Comparator
Phase-Locked Loops (PLL)
Definition: Phase-locked loops are the circuits used to maintain synchronization between input and output frequency of oscillator circuits by comparing the difference in phase of the two signals. With the evolution of IC, it has emerged as the basic building block of electronic circuits. Phase-locked loops are abbreviated as PLL and are basically a feedback circuit comprising of a phase detector (or comparator), a low pass filter and voltage-controlled oscillator along with an … [Read more...] about Phase-Locked Loops (PLL)
Synchronous Counter
Definition: The synchronous counter is a type of counter in which the clock signal is simultaneously provided to each flip-flop present in the counter circuit. More specifically, we can say that each flip-flop is triggered in synchronism with the clock input. Unlike asynchronous counter where separate clock pulses are used to trigger the flip-flop, all the flip-flops in synchronous counters are triggered using a single clock pulse. We know designing an asynchronous counter is easy then … [Read more...] about Synchronous Counter
Asynchronous Counter
Definition: Asynchronous counters are those counters which do not operate on simultaneous clocking. In asynchronous counter, only the first flip-flop is externally clocked using clock pulse while the clock input for the successive flip-flops will be the output from a previous flip-flop. This means that only a single clock pulse is not driving all the flip-flops in the arrangement of the counter. Asynchronous counters are also known as ripple counters and are formed by the successive … [Read more...] about Asynchronous Counter
Companding
Definition: Companding is a technique of achieving non-uniform quantization. It is a word formed by the combination of words compression and expanding. Companding is done in order to improve SNR of weak signals. We know if the characteristics of the quantizer is non-linear then it causes the step size to be variable despite being constant then it is known as non-uniform quantization. As we know in non-uniform quantization, the step size varies according to the signal level.If the signal … [Read more...] about Companding