Sound Recording and Reproduction
... In a home audio system, the term 'preamplifier' may sometimes be used to describe equipment which merely switches between different line level sources and applies a volume control, so that no actual amplification may be involved. In an audio system, the second amplifier is typically a power amplifie ...
... In a home audio system, the term 'preamplifier' may sometimes be used to describe equipment which merely switches between different line level sources and applies a volume control, so that no actual amplification may be involved. In an audio system, the second amplifier is typically a power amplifie ...
• - No Brain Too Small
... The two forces shown here are equal and opposite, but they are displaced vertically, so they exert a torque. (The forces on the other two sides of the coil act along the same line and so exert no torque.) The split ring ensures this is a DC motor. When the plane of the rotating coil reaches horizont ...
... The two forces shown here are equal and opposite, but they are displaced vertically, so they exert a torque. (The forces on the other two sides of the coil act along the same line and so exert no torque.) The split ring ensures this is a DC motor. When the plane of the rotating coil reaches horizont ...
Downloadable Full Text - DSpace@MIT
... in a transformer, where the magnetic field is typically confined to a high permeability core, also functions when the region between the primary and secondary coils is simply air. Inductive coupling without high permeability cores is used, for example, to power RF ID tags and medical implants [1]–[3 ...
... in a transformer, where the magnetic field is typically confined to a high permeability core, also functions when the region between the primary and secondary coils is simply air. Inductive coupling without high permeability cores is used, for example, to power RF ID tags and medical implants [1]–[3 ...
Instrumentation and Measurement Techniques
... voltage level to ac electrical energy at another voltage level, but with the same frequency. In general, transformers operate on the same principles as generators and motors, and are usually studied together with generators and motors. These 3 types of devices are inevitable in modern daily life. *M ...
... voltage level to ac electrical energy at another voltage level, but with the same frequency. In general, transformers operate on the same principles as generators and motors, and are usually studied together with generators and motors. These 3 types of devices are inevitable in modern daily life. *M ...
Electromagnetic Induction3
... d) Two coils of self – inductances L1 and L2, placed far away (i.e., without coupling) from each other. i) For series combination: L = L + L ....... L ...
... d) Two coils of self – inductances L1 and L2, placed far away (i.e., without coupling) from each other. i) For series combination: L = L + L ....... L ...
Inductors - ECE Labs
... • Inductance is measured in Henries (H) • 1 Henry is the inductance level that will establish a voltage of 1 volt across the coil ...
... • Inductance is measured in Henries (H) • 1 Henry is the inductance level that will establish a voltage of 1 volt across the coil ...
Abstract and References
... ABSTRACT The structure of power supply system for autonomous underwater vehicle is analyzed. Topicality of the use of contactless electrical power transmission method is detailed. Specific character of this method is described. It is connected with the use of high-frequency transformer. Its primary ...
... ABSTRACT The structure of power supply system for autonomous underwater vehicle is analyzed. Topicality of the use of contactless electrical power transmission method is detailed. Specific character of this method is described. It is connected with the use of high-frequency transformer. Its primary ...
Two ways of looking at a transformer
... 1/(2 x 0.1) = (4 x 10-7) x 1/(2 x 0.1) = 2 x 10-6 T. This flux density can cause a force of BIL = 2 x 10-6 x 1 x 0.1 = 2 x 10-7 N to act in an 0.1-m long wire carrying 1 A. This does not seem to be a very large force, so we need either lots of wire, or more current, or a stronger field, or prefer ...
... 1/(2 x 0.1) = (4 x 10-7) x 1/(2 x 0.1) = 2 x 10-6 T. This flux density can cause a force of BIL = 2 x 10-6 x 1 x 0.1 = 2 x 10-7 N to act in an 0.1-m long wire carrying 1 A. This does not seem to be a very large force, so we need either lots of wire, or more current, or a stronger field, or prefer ...
10.3 The ideal transformer
... ① Used for changing AC voltage levels. ② Transmission line : high voltage levels are used to decrease power loss due to ...
... ① Used for changing AC voltage levels. ② Transmission line : high voltage levels are used to decrease power loss due to ...
Resonant inductive coupling
Resonant inductive coupling or electrodynamic induction is the near field wireless transmission of electrical energy between two magnetically coupled coils that are part of resonant circuits tuned to resonate at the same frequency. This process occurs in a resonant transformer, an electrical component which consists of two high Q coils wound on the same core with capacitors connected across the windings to make two coupled LC circuits. Resonant transformers are widely used in radio circuits as bandpass filters, and in switching power supplies. Resonant inductive coupling is also being used in wireless power systems. Here the two LC circuits are in different devices; a transmitter coil in one device transmits electric power across an intervening space to a resonant receiver coil in another device. This technology is being developed for powering and charging portable devices such as cellphones and tablet computers at a distance, without being tethered to an outlet.Resonant transfer works by making a coil ring with an oscillating current. This generates an oscillating magnetic field. Because the coil is highly resonant, any energy placed in the coil dies away relatively slowly over very many cycles; but if a second coil is brought near it, the coil can pick up most of the energy before it is lost, even if it is some distance away. The fields used are predominately non-radiative, near fields (sometimes called evanescent waves), as all hardware is kept well within the 1/4 wavelength distance they radiate little energy from the transmitter to infinity.One of the applications of the resonant transformer is for the CCFL inverter. Another application of the resonant transformer is to couple between stages of a superheterodyne receiver, where the selectivity of the receiver is provided by tuned transformers in the intermediate-frequency amplifiers. The Tesla coil is a resonant transformer circuit used to generate very high voltages, and is able to provide much higher current than high voltage electrostatic machines such as the Van de Graaff generator. Resonant energy transfer is the operating principle behind proposed short range (up to 2 metre) wireless electricity systems such as WiTricity or Rezence and systems that have already been deployed, such as Qi power transfer, passive RFID tags and contactless smart cards.