Evolution of Television Technology: From Analog to Hybrid
Special Circuits and Synchronization
Synchronization is achieved by recovering the video signal’s sync pulses. Synchronization and horizontal sweep are responsible for image deployment, providing a horizontal signal. Functions are related to the high voltage generator, exciting the anode in the kinescope.
Modern TVs use switching power supplies to generate various voltages for different circuits. Erase and sync pulses function by sending a signal that occupies all the time, with thin sync pulses directly
Read MoreSpeed, Temperature, and Pressure Transducers
Speed Transducers
The measurement of angular velocity in industry is commonly achieved using tachometers, which can be either mechanical or electrical. The measurement result directly expresses the angular velocity in revolutions per minute. Tachometers can measure the average speed over a time interval or the instantaneous velocity.
Mechanical Tachometers
A revolution counter uses a screw shaft coupled to the engine whose speed is to be measured. This screw is rotated through a gear system with two
Read MorePolymer Processing and Material Properties: A Comprehensive Look
Polymer Forming Processes
- Extrusion: Circulating granulated plastic inside a heated tube. The plastic mass is pushed out at one end of the tube, where it is given shape and cooled.
- Blow Molding: A tube is extruded and enclosed inside a mold under pressure.
- Injection Molding: Granulated plastic is circulated inside a heated tube. When the melt reaches the end of the tube, the screw is removed, and then the finished piece is ejected.
- Foam Molding: The material is placed within a mold and heated. The
Capacitors, Magnetic Fields, and Transistors: Electrical Components
Capacitors
Condensers are composed of two metal plates, called armatures, separated by an insulating material called the dielectric. When a voltage is applied, the dielectric prevents current flow, causing charge accumulation on the armatures. Negative charge accumulates on the armature connected to the battery’s negative pole, and positive charge accumulates on the armature connected to the positive pole.
The dielectric becomes polarized due to the accumulated charge. When the voltage is disconnected,
Read MoreMeasurement and Detection Devices: Types and Uses
Types of Measurement and Detection Devices
Detection Devices
Detection devices are responsible for perceiving the proximity of an object or its position. If the detection is performed by physical contact with the object, they are electromechanical switches. These are the most used position switches and they detect the position of an object. If the detection is done without physical contact, it is called proximity detection. Within the latter, there are AC, DC, and photoelectric types.
Measuring Apparatus
These
Read MoreKey Alloying Elements in Steel: Properties and Uses
Nickel
Nickel was one of the first metals used as an alloying element in the manufacture of special steels. This element was first used in the late nineteenth century. It was noted that adding 2-5% nickel to carbon steels increased their strength and yield strength without reducing toughness.
Nickel is an extremely important element in the manufacture of stainless steel and provides resistance to high temperatures. These steels are austenitic at room temperature and do not support tempering. The iron-
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