Chapter 16 Electromagnetism
... (4) Slightly move the semiconductor slice inside the solenoid and record the maximum Hall voltage to ensure that the slice is perpendicular to the magnetic field in the solenoid. (5) Repeat the procedure at different positions along the solenoid, so as to obtain the variation of magnetic flux densit ...
... (4) Slightly move the semiconductor slice inside the solenoid and record the maximum Hall voltage to ensure that the slice is perpendicular to the magnetic field in the solenoid. (5) Repeat the procedure at different positions along the solenoid, so as to obtain the variation of magnetic flux densit ...
mk484 am radio receiver with varicap tuning
... Next, L2 is fed in to pin 2 of U1, an MK484 Tuned Radio Frequency (TRF) IC which contains around ten transistors on board providing all the necessary RF and IF amplification and an AM detector. This IC requires only a maximum of 1.8V to operate, so this is biased at pin 3 via R3 to provide the neces ...
... Next, L2 is fed in to pin 2 of U1, an MK484 Tuned Radio Frequency (TRF) IC which contains around ten transistors on board providing all the necessary RF and IF amplification and an AM detector. This IC requires only a maximum of 1.8V to operate, so this is biased at pin 3 via R3 to provide the neces ...
Magnetic Measurements - Spontaneous Materials
... hysteresis loop. Again, a nickel standard is used for calibration. A typical configuration is shown in figure 9. This method can measure the entire hysteresis loop very quickly. Measurements can be made from -40 to 200 °C, without too much difficulty. Since this is a dynamic measurement, eddy curren ...
... hysteresis loop. Again, a nickel standard is used for calibration. A typical configuration is shown in figure 9. This method can measure the entire hysteresis loop very quickly. Measurements can be made from -40 to 200 °C, without too much difficulty. Since this is a dynamic measurement, eddy curren ...
Principles of Electronic Communication Systems
... Ripple is a term used to describe the amplitude variation with frequency in the passband. Shape factor is the ratio of the stop bandwidth to the pass bandwidth of a bandpass filter. A pole is a frequency at which there is a high impedance in the circuit. Zero is a term used to refer to a frequency a ...
... Ripple is a term used to describe the amplitude variation with frequency in the passband. Shape factor is the ratio of the stop bandwidth to the pass bandwidth of a bandpass filter. A pole is a frequency at which there is a high impedance in the circuit. Zero is a term used to refer to a frequency a ...
Eddy Current Losses
... connected in parallel across a supply. Secondaries are connected in series such that emf's of them are opposite to each other. Another low voltage supply is connected in series with secondaries to get the readings In above diagram, T1 and T2 are identical transformers. Secondaries of them are connec ...
... connected in parallel across a supply. Secondaries are connected in series such that emf's of them are opposite to each other. Another low voltage supply is connected in series with secondaries to get the readings In above diagram, T1 and T2 are identical transformers. Secondaries of them are connec ...
RF Energy Harvesting, Maximum Power Point Tracking, Energy
... which has no battery on it. The fact that passive tags need no power supply makes it much cost-effective and long-lasting than active tags[10]. RFID devices provide a real-t ime co mmun ication with numerous distant objects at a time through radio waves, with increased accuracy, efficiency and proce ...
... which has no battery on it. The fact that passive tags need no power supply makes it much cost-effective and long-lasting than active tags[10]. RFID devices provide a real-t ime co mmun ication with numerous distant objects at a time through radio waves, with increased accuracy, efficiency and proce ...
Single-chip detector for electron spin resonance spectroscopy
... 共PLL兲 circuitry for frequency-to-voltage conversion. The signal at the output of the PLL is demodulated by a lock-in amplifier. The lock-in internal reference signal is amplified and delivered to the field modulation coil. The spin sensitivity of the realized microsystem is evaluated by measuring th ...
... 共PLL兲 circuitry for frequency-to-voltage conversion. The signal at the output of the PLL is demodulated by a lock-in amplifier. The lock-in internal reference signal is amplified and delivered to the field modulation coil. The spin sensitivity of the realized microsystem is evaluated by measuring th ...
High End Fed
... Tuning : The trick to tune this transformer is to find the working frequency first by tuning the capacitor. Then we look for the the 50 Ohm point on the coil . Connect a 3300 Ohm resistor from the top of the coil to the ground of the antenna plug. Adjust the length of the open coax line until you re ...
... Tuning : The trick to tune this transformer is to find the working frequency first by tuning the capacitor. Then we look for the the 50 Ohm point on the coil . Connect a 3300 Ohm resistor from the top of the coil to the ground of the antenna plug. Adjust the length of the open coax line until you re ...
Simulated Inductance
... • Inductors are far from ideal devices – Parasitic resistance because of the length of wire used to form the inductor. – Parasitic capacitance because of coupling between parallel loops of wire. ...
... • Inductors are far from ideal devices – Parasitic resistance because of the length of wire used to form the inductor. – Parasitic capacitance because of coupling between parallel loops of wire. ...
Bab 3
... If more power is required, use the SCR with a full wave bridge circuit (Fig. 7-9). In control application, the controller output signal would be used to drive a circuit that changed the time at which the pulses were applied to the gates, and thus changed the power applied to the load. The volt ...
... If more power is required, use the SCR with a full wave bridge circuit (Fig. 7-9). In control application, the controller output signal would be used to drive a circuit that changed the time at which the pulses were applied to the gates, and thus changed the power applied to the load. The volt ...
The Electromagnetic Pulse Technology (EMPT
... The electromagnetic pulse technology (EMPT) provides non-contact processes for joining, welding, forming and cutting of metals by application of strong, short pulsed magnetic fields. This technique came up in the 1960’s and was adopted by many researchers within the following decade. The research wo ...
... The electromagnetic pulse technology (EMPT) provides non-contact processes for joining, welding, forming and cutting of metals by application of strong, short pulsed magnetic fields. This technique came up in the 1960’s and was adopted by many researchers within the following decade. The research wo ...
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.