Difference Between AC and DC Currents | AC and DC Waveforms

AC and DC Currents:

Conductive materials contain free electrons that move from one atom to another when the potential difference between them is applied. This flow of electrons in a closed circuit is called current. Based on the direction of motion of the electrons in a closed circuit, the electric current is mainly classified into two types, namely alternating current and direct current.

Difference between AC and DC

Electric current can be generated in two ways, AC (alternating current) and DC (direct current). Electricity can be defined as the flow of electrons through a wire-like conductor. The main difference between AC and DC is mainly in the direction in which the electrons are supplied. In direct current, the flow of electrons is in the same direction and in alternating current; The flow of electrons changes their directions as they move forward and then backward. The difference between AC and DC mainly consists of the following.

What is AC Current?

The AC current changes its polarity and magnitude periodically and continuously with respect to time. The Ac current can be produced with a device named alternator that produces the alternating current.

AC Wave Form

 

AC Current Circuit

What is DC Current?

The DC current is a unidirectional flow of current or electric charge unlike AC it does not change the magnitude and polarity with time. The DC current has constant magnitude and direction and as the direction and magnitude not changes so the frequency of DC current is zero. The electrons in DC current flow from high electron density to low electron density.

Application of AC

• AC is used for long-distance transmission for Offices and Homes
• Energy Loss in AC is less so widely used in transmission
• The AC current can be converted into a high voltage to low voltage and low to high voltage efficiently using the transformer
• AC power is used in larger applications and appliances like Freezers, AC. Dishwashers, washing machines, Fans, Bulbs.

Application of DC current

• DC current is widely used in small electronic devices and gadgets
• DC current is not good for long-distance transmission but storage of dc current is easy in form of Battery.
• DC power is used in Cell phones, laptops, radio and other electronic gadgets
• DC Current are used in flashlights
• DC current are used in EV and hybrid cars and automobile

Difference between AC and DC

• Ac current changes its direction during flow while the DC current does not changes its direction during flow and remains constant.
• The AC current has a frequency that shows how many times the direction of current flow changes during flow while the frequency of the direct current is zero as it do not change the direction of flow.
• The power factor of AC is 0 to 1 While DC is Constant Zero.
• The AC current is generated by the alternator while DC current is generated by Photovoltaic cells, generators and batteries.
• The AC load can be capacitive, inductive or resistive but the load on DC is always resistive.
• The DC current graph has a constant line showing magnitude and direction is constant while the AC current can be a sinusoidal wave, square wave or triangular wave.
• The AC converted into DC using a device named rectifier while the DC converted into AC named inverter.
• AC is widely used in industrial equipment and consumer electronics like AC, Freezer, Cooler, washing machine, lights, fans While DC is used in electronic gadgets and small devices like clocks, laptops, cell phones, Sensors.
• Ac can be transmitted over long distance with some loss while DC can be transmitted very long distance with very low loss using HVDC

Difference Between Latch and Flip-Flop | Latch vs Flip-Flop MCQ

In this article, we discuss both latch and flip-flop are considered as the fundamental elements of the electronic system. The crucial difference between Latch and Flip-Flop is that a latch changes its output regularly according to the change in the applied input signal when it is enabled. As against in a flip flop, the output changes with input in conjunction with the clock signal. This means the clock signal acts as the control signal to display the output according to the changed input.

Latches are something in your design that always needs attention. There are tools that help designers pinpoint the existence of latches in their design as ‘must know’ information. Thus, latches and flip flops are considered as the derived sequential circuits that are used to store information. Here we will discuss all those factors which differentiate a latch from a flip-flop.

Latch:

The latch is an electronic circuit, which changes its output immediately based on the applied input. It is used to store either 1 or 0 at any specified time. It consists of two inputs namely “SET” and RESET and two outputs, which are a complement each other.

Flip-Flop:

Flip-Flop is a basic digital memory circuit, which stores one bit of information. Flip flops are the fundamental blocks of most sequential circuits. It is also known as a bistable multivibrator or a binary or one-bit memory. Flip-flops are used as memory elements in sequential circuits.

 

Difference Between Latch and Flip-Flop

Latch	Flip-Flop
The latch is transparent – because the input is directly connected to output when enable is high. It means Latch is sensitive to pulse duration (also called soft barrier)	Flip-flop is a pair of latches (master and slave flop). Flip-flop is sensitive to pulse transition. The signal only propagates through on the rising/falling edge (also called hard barrier)
Less Area (fewer gates)	More Area (more gates) because flip-flop contains two latches.
Less Power (fewer gates)	More Power (more gates)
Fast –(The longer combinational path can be compensated by shorter path delays in the subsequent logic stages. That’s why, for higher performance, circuits designer are turning to latched-based design.)	Slow –(The delay of a combinational logic path of a design using edge-triggered flip-flops always less than the clock period except for those specified as false paths and multiple-cycle paths. Hence the longest path of a design limits the circuit performance.)
Require more tool manipulation and more hand-calculations to verify that they meet timing	Easy to check design timing using Static Timing Analysis (STA) tools
Cycle-borrowing to gain more setup time on the next register stage, as long as each loop completes in one cycle To meet the timing in the design, Designers consider latches to adjust timing mismatch.	Data launches on one rising edge, so it must set up before the next rising edge. If it arrives late, the system fails. If it arrives early, time is wasted due to hard edges in Flops
For ASICs with large clock skew, latches have substantial benefits for reducing the clock period	Even for the high-speed pulsed flip-flops with zero setup time, as they are not transparent, the impact of the clock skew is not reduced
Level-sensitive latches reduce the impact of the inaccuracy of wire load models and process variation.	Flip-flops demands the highly accurate wire load model and process
In DFT, Latches needed as a lockup state at the clock domain crossings in the scan chain to avoid unpredictable behavior	In DFT, use flops that can be scanned (controllable and observable)
In FPGA, level-sensitive transparent latches should be avoided in FPGAs	In FPGA, edge-sensitive flip-flops are used exclusively. Timings analysis is more appropriate with flops for FPGA tools
Circuit analysis is complex. You may see last minutes timing mismatch surprises at the implantation stage.	Circuit analysis is easy
High-speed microprocessor designs typically use master-slave latches instead of flip-flops so that logic can be added between the rising and falling clock edges. Most of these companies have written their own specialized STA tools to verify latch-based designs.	The most commonly used flop in the design world is the D-type flip-flop. FSM implementation mostly involves D Flip-flops due to a minimum number of logic gates and lesser cost as compared to other types of flip-flops.
For non-timing-critical configuration registers, latches work great, due to fewer gates and less power consumption	For non-power aware design, Flip flops are preferred over Latches
The latch is an asynchronous block. Therefore you must ensure that the combinational functions, which generate input signals for the latch, are race-free. Otherwise, they may generate glitches, which may be latched, causing hazards in your system.	A flip-flop, on the other hand, is edge-triggered and only changes state when a control signal goes from high to low or low to high
Latch-based design is noisy because any noise in the enable signal disrupts the latch output easily.	Flip-flop based design is robust

Digital Circuits Questions and Answers – Latch vs Flip-Flop MCQ:

1. Latches constructed with NOR and NAND gates tend to remain in the latched condition due to which configuration feature?
a) Low input voltages
b) Synchronous operation
c) Gate impedance
d) Cross-coupling

A) d

2. One example of the use of an S-R flip-flop is as ___________
a) Transition pulse generator
b) Racer
c) Switch debouncer
d) Astable oscillato

A) c

3. The truth table for an S-R flip-flop has how many VALID entries?
a) 1
b) 2
c) 3
d) 4

A) c

4. When both inputs of a J-K flip-flop cycle, the output will ___________
a) Be invalid
b) Change
c) Not change
d) Toggle

A) c

5. Which of the following is correct for a gated D-type flip-flop?
a) The Q output is either SET or RESET as soon as the D input goes HIGH or LOW
b) The output complement follows the input when enabled
c) Only one of the inputs can be HIGH at a time
d) The output toggles if one of the inputs is held HIGH

A) a

6. A basic S-R flip-flop can be constructed by cross-coupling of which basic logic gates?
a) AND or OR gates
b) XOR or XNOR gates
c) NOR or NAND gates
d) AND or NOR gates

A) c

7. The logic circuits whose outputs at any instant of time depends only on the present input but also on the past outputs are called ________________
a) Combinational circuits
b) Sequential circuits
c) Latches
d) Flip-flops

A) b

8. Whose operations are more faster among the following?
a) Combinational circuits
b) Sequential circuits
c) Latches
d) Flip-flops

A) a

9. How many types of sequential circuits are?
a) 2
b) 3
c) 4
d) 5

A) a

10. The sequential circuit is also called ___________
a) Flip-flop
b) Latch
c) Strobe
d) Adder

A) b

Related:

difference between latch and flip flop with the timing diagram
difference between latch and flip flop waveform
difference between latch and flip flop ppt
difference between latch and flip flop MCQ

Difference between Microprocessor and Microcontroller Applications

The two words Microcontroller and Microprocessor look alike but there is a lot of difference between these two ICs. The chip on the microprocessor has the same CPU as most Intel processors, but the microcontroller includes the CPU or processor as well as RAM, ROM and other peripherals. The two ICs (Microcontroller and Microprocessor) have different applications and have their own advantages and disadvantages. They can be distinguished in terms of applications, architecture, internal parameters, power consumption and cost. Let’s look in detail at the difference between a microprocessor and a microcontroller.

 

Difference between Microprocessor and Microcontroller

Applications of Microcontroller and Microprocessor:

The Microcontroller is designed for a specific task and the program is built into the MCU chip, it cannot be easily modified and you may need special tools to re-record it. The microcontroller process is fixed according to your application. So it does some processing based on the input given to the microcontroller and gives pre-defined results as output. Input can be given by the user or by sensors.

The Microcontroller used in many electronic devices such as washing machines, microwaves, and timers. On these machines, the process is pre-defined, which may require some user input to give a pre-defined output. Tell the washing machine, after the user has set the input parameters, to wash the clothes according to the input parameter. So the basic task for the washing machine is solved. You can do nothing more than wash the machine.

The Microprocessor used in applications like where the task is not pre defined by user. It is used in Electronic equipment’s like Mobiles, Computers, Video Game Consoles, Televisions, etc., where the work is not static and depends on the user. Generally, a microprocessor is used where intensive processing is required. The laptop is the best example of using a microprocessor. The laptop can be used for media streaming, emulation, image editing, web browsing, gaming, document creation and more.

Difference Between Microprocessor and Microcontroller: Applications

Microprocessor	Microcontroller
A microprocessor is a controlling unit of a micro-computer wrapped inside a small chip.	A microcontroller is a chip optimized to control electronic devices.
Microprocessor consists of only a Central Processing Unit.	Micro Controller contains a CPU, Memory, I/O all integrated into one chip.
Microprocessor is used in Personal Computers whereas Micro Controller is used in an embedded system.	Micro Controller is used in an embedded system.
Microprocessor uses an external bus to interface to RAM, ROM, and other peripherals.	Microcontroller uses an internal controlling bus.
Microprocessor is complicated and expensive, with a large number of instructions to process.	Microcontroller is inexpensive and straightforward with fewer instructions to process.
Microprocessors are based on Von Neumann model	Micro controllers are based on Harvard architecture

 

Types of Microprocessor

types of Microprocessors are:

• Complex Instruction Set Microprocessors
• The Application Specific Integrated Circuit
• Reduced Instruction Set Microprocessors
• Digital Signal Multiprocessors (DSPs)

Types of Microcontroller

types of Microcontroller:

• 8 bit Microcontroller
• 16 bit Microcontroller
• 32 bit Microcontroller
• Embedded Microcontroller
• External memory Microcontroller

Applications of Microprocessor

Microprocessors are mainly used in devices like:

• Calculators
• Accounting system
• Games machine
• Complex industrial controllers
• Traffic light
• Control data
• Military applications
• Defense systems
• Computation systems

Applications of Microcontroller

Microcontrollers are mainly used in devices like:

• Mobile phones
• Automobiles
• CD/DVD players
• Washing machines
• Cameras
• Security alarms
• Keyboard controllers
• Microwave oven
• Watches
• Mp3 players