211 SRI RAMAKRISHNA MISSION VIDYALYA POLYTECHNIC COLLEGE.

  Difference Between AC And DC Motor The difference between AC and DC Motor are discussed below: AC Motor vs DC Motor AC Motor DC Motor AC motor runs on alternating current. DC motors operate on direct current. There is no need for conversion of current in AC motors. Like AC. There is no need for conversion of current in AC motors. Like AC. AC motors are used where power performance is demanded for extended periods of time. DC motors are used where the speed of the motor needs to be controlled externally. AC motors can be single-phase or three-phase. All DC motors are single phase. In an AC motor the armature does not rotate while the magnetic field keeps rotating continuously. In a DC motor, the armature rotates while the magnetic field rotates. Repairing AC motors is not expensive. DC motors are very expensive to repair. Brushes are not used in AC motor. Brushes are used in DC motor. AC motors have a very long life span DC motors do not have a very long life span. The speed of AC...

One concern with nuclear energy is radiation. However, Betavolt assures users that their battery is safe, with no external radiation. They claim that it is suitable for use in medical devices inside the human body, like pacemakers and cochlear implants. After the decay period, the 63 isotopes transform into a stable, non-radioactive isotope of copper, posing no environmental threat or pollution. Notably, the BV100 battery developed by Betavolt is also more secure compared to conventional batteries. It does not catch fire or explode when punctured or exposed to high temperatures, making it a safer option. The development of miniaturized nuclear batteries has long been a goal for scientists. The Soviet Union and the United States previously explored this technology for use in spacecraft, underwater systems, and remote scientific stations. However, these batteries were expensive and bulky. Under China's 14th Five-Year Plan, efforts were made to miniaturize and commercialize nuclear ba...

  Applications of 8051 Microcontroller Even with the development of many advanced and superior Microcontrollers, 8051 Microcontroller is still being used in many embedded system and applications. Some of the applications of 8051 Microcontroller are mentioned below: Consumer Appliances (TV Tuners, Remote controls, Computers, Sewing Machines, etc.) Home Applications (TVs, VCR, Video Games, Camcorder, Music Instruments, Home Security Systems, Garage Door Openers, etc.) Communication Systems (Mobile Phones, Intercoms, Answering Machines, Paging Devices, etc.) Office (Fax Machines, Printers, Copiers, Laser Printers, etc.) Automobiles (Air Bags, ABS, Engine Control, Transmission Control, Temperature Control, Keyless Entry, etc) Aeronautical and Space Medical Equipment Defense Systems Robotics Industrial Process and Flow Control Radio and Networking Equipment Remote Sensing

  Importance of Earthing The earthing is essential because of the following reasons The earthing protects the personnel from the shortcircuit current. The earthing provides the easiest path to the flow of shortcircuit current even after the failure of the insulation. The earthing protects the apparatus and personnel from the high voltage surges and lightning discharge. Earthing can be done by electrically connecting the respective parts in the installation to some system of electrical conductors or electrodes placed near the soil or below the ground level. The earthing mat or electrode under the ground level have flat iron riser through which all the non-current-carrying metallic parts of the equipment are connected. When the fault occurs the fault current from the equipment flows through the earthing system to the earth and thereby protect the equipment from the fault current. At the time of the fault, the earth mat conductors rise to the voltage which is equal to the resistance o...

  Which motor is used in today's laser or inkjet printer? Most recent HP printers do not use stepper motors, but rather use DC motors that use external sensors for active positional feedback. These motors are designed to operate from 18-32V but can also run on 6 or 12V DC. To identify the DC motors, look for the two wires coming out of the motor. Stepper motor is identified as motors having more leads. It is employed for the movement of the cartridge. This to and fro movement is what enables ink application on the paper. The two types of stepper motors are unipolar and bipolar. Bipolar motors require a processor for precise control and are employed only in the high-end printer

  Betavolt , a Chinese startup, has announced that it has developed a revolutionary battery capable of powering smartphones for an impressive 50 years without requiring recharging. Termed as the world's first miniaturized atomic energy system, this  nuclear battery  utilizes 63 nuclear isotopes compactly arranged within a module smaller than a coin.

  Precautions in Connecting Booster Transformer The following precautions are to be taken while connecting a booster transformer in the traction circuit  1.  Booster transformer should be able to withstand severe mechanical stresses which will develop due the current of thousands of amperes under the conditions of short-circuit.   2.  Primary winding insulation of the booster transformer should be kept at 25 kV, while secondary winding insulation is kept at 3 kV because a high potential is created in the secondary winding under fault conditions. 3.  The booster transformer should not be located near the signals or the places where the train is likely to stop.

  Thin and flexible OLEDs are thinner than LEDs and can be made with flexible materials for foldable or rollable displays. Enhanced colour and contrast Individual OLED pixels generate their own light, improving colour and contrast control. OLEDs can acheive true blacks when the pixel is turned off. Fast response time OLEDs have a faster response time than LEDs. This means they can refresh faster, reducing motion blur and provide smoother transitions. Higher cost Fabricating OLED displays is more expensive than manufacturing LED displays. This higher cost is often passed on to consumers, making OLED-based devices pricier. Shorter lifespan OLEDs have a shorter lifespan than LED displays. The organic materials used in OLEDs can degrade over time, leading to colour and brightness issues.

 Comparison  Microprocessor Microcontroller Since memory and I/O are connected externally, the circuit becomes large in size. Since memory and I/O are present together, the internal circuit is small in size. It cannot be used in compact systems It can be used in compact systems. Cost is high Cost is low It is not suitable for devices that run on stored power since total power consumption is high due to external components. It can be used on devices that use stored power since total power consumption is low due to less external components. RAM, ROM, I/O units, and other peripherals are not embedded on a single chip. RAM, ROM, CPU and other peripherals are embedded on a single chip. Do not have power saving mode. Have a power-saving mode. Used in personal computers. Used in embedded systems. Less number of registers. More number of registers.  Uses an external bus. Uses an internal controlling bus. Based on the Von Neumann model Based on the Harvard architecture It is a cen...

  Self Inductance Definition:  When the current-carrying coil has the property of self-inductance, then it resists the change in the current flow is known as self-inductance.  This mainly occurs when the self-induced e.m.f is generated within  the coil . In other words, it can be defined as when the voltage induction occurs within a current-carrying wire. Self Inductance When the current increases or decreases, the self-induced e.m.f will resist the current.  Basically, the path of the induced e.m.f is reverse to the voltage applied, if the current is rising.  Similarly, the path of the induced  e.m.f  is in a similar direction to the applied voltage, if the flow of current is reducing.

  LDR Working Principle It works on the principle of photoconductivity whenever the light falls on its photoconductive material, it absorbs its energy and the electrons of that photoconductive material in the valence band get excited and go to the conduction band and thus increasing the conductivity as per the increase in light intensity. Also, the energy in incident light should be greater than the bandgap gap energy so that the electrons from the valence band got excited and go to the conduction band. The LDR has the highest resistance in dark around 1012 Ohm and this resistance decreases with the increase in Light. Light Intensity V/S Resistance As per the property of LDRs, the amount of light entering the LDR the inversely proportional to the resistance of the sensor, and the graph is hyperbolic in nature.