Automatic Block Signalling System in Railways: The purpose of automatic block signalling system in railways is to keep trains apart but permit spacing as close as safety permits. For optimum utilization of track capacity with…
Auto Transformer Starter - Working Principle, Advantages and Disadvantages: In auto transformer starter method the reduced voltage is obtained by taking tappings at suitable points from a three phase auto-transformer, as shown in Fig. 1.70(a).…
Auto Reclosing Scheme: Auto Reclosing Scheme - It is well realized that the transient faults which are most frequent in occurrence do no permanent damage to the system as they are transitory in nature. These…
Audio Power Amplifier using IC Amplifier Driver: The LM391 integrated circuit Audio Power Amplifier using IC Amplifier Driver contains amplification and driver stages for controlling an externally-connected Class-AB output stage delivering 10 W to 100…
Audio Frequency Transformer: Audio Frequency Transformer is used at the output stage of Audio Frequency electronic amplifier for matching the load to the output impedance of the power amplifier stage. Here the load is fixed…
Audio Amplifier Frequency Response: The Audio Amplifier Frequency Response is essential for filters, couplings circuits, amplifier stages and overall audio circuits. An amplifier stage is used as an example. A test setup for this amplifier…
Attenuators in Network Analysis: In various transmission equipments, it is many times required to supress or reduce the levels of the currents and voltages at certain points. To fulfill the need of attenuation, a four…
Attenuators: Attenuators are designed to change the magnitude of the input signal seen at the input stage, while presenting a constant impedance on all ranges at the attenuator input. A compensated RC attenuator is required…
Attenuator Network: An attenuator network must fulfil following conditions. It must give correct input impedance, It must give correct output impedance and It must provide specified attenuation. In general, attenuation is expressed in decibel as…
Atomic Hydrogen Welding Working Principle and Applications: The principle of atomic hydrogen welding is based on (i) the possibility of obtaining atomic hydrogen by means of an electric arc between the two tungsten electrodes, in…
