Telecommunications Signals and Transmission Media
Mathematical Concepts
A signal is only the manifestation of a physical quantity. In the case of signals used in telecommunications, this signal has a characteristic: it can spread through various means and channels. This suggests the idea of mathematically representing the signal as a function variable over time.
- Frequency: The frequency reports on the number of sections of the horizontal axis function per unit time, measured in hertz (Hz).
- Period: The period reports the time needed for a repetition
Lithium-ion vs. Lead Acid Batteries: Degradation, Safety, and Applications
Lithium-ion Battery Degradation
Lithium-ion battery degradation has two primary effects:
- Decrease in rated capacity
- Reduction in the ability to deliver power
Calendar Life
Avoid storing batteries fully charged or discharged. A State of Charge (SOC) of around 40% at 3-8 degrees Celsius is optimal.
Cycle Life
High and low temperatures accelerate cell aging. Avoid charging in extreme temperatures.
High Depth of Discharge (DoD) also contributes to cell aging.
High discharge currents degrade the cell more rapidly.
Read MoreKey Concepts in Signal Modulation and Transmission
Modulation and Its Types
Modulation is a process where the time function that describes the information signal is multiplied by another signal, most often called a carrier.
- Angular Modulation
- Amplitude Modulation
- DSB-SC (Double Sideband Suppressed Carrier)
- AM (Amplitude Modulation)
- SSB (Single Sideband)
- VSB (Vestigial Sideband)
- Frequency Modulation
- NBFM (Narrowband Frequency Modulation)
- VBFM (Very Narrowband Frequency Modulation)
- Phase Modulation
- Narrow Band
- Broadband
Selectivity
Selectivity measures the ability
Read MoreElectrochemical Accumulators: Types, Parameters & Usage
Electrochemical Accumulators
Electrochemical accumulators store energy. Common types include nickel-cadmium and lead-acid.
Lead-Acid Accumulators
Lead-acid accumulators consist of 2V independent vessels or a 6-cell monoblock (12V total), connected in series. The electrolyte is a diluted sulfuric acid solution (density between 1.1 and 1.30 g/cm³) acting as a conductive element between the battery plates. A single cell has a voltage of 2V (2.6V when loaded, 1.7V when discharged), while a monoblock has
Read MoreIndustrial Sensors: Types, Uses, and Connectivity
Industrial Sensors
There are different types of detectors, all of which have a functioning electronic circuit. Their functions include:
- Detecting items
- Determining position
- Discriminating by size, color, and type of material
- Detecting levels of liquids and solids
Types of Detectors
- Inductive
- Capacitive
- Photoelectric
- Fiber-Optic
Inductive Sensors
- Inductive detectors can detect a target at a close distance (from 0 to 60 mm) without the need for physical contact.
- The target to be detected must be metallic.
- They
Electrical Motors and Control Systems: Types, Operation, and Applications
Three-Phase Asynchronous Motors: Rotor Winding
Three-phase asynchronous motors comprise a stator winding and a rotor winding, star-connected at one end, with three free terminal ends connected to three collector rings. These rings have three brushes that slide across them. The terminals of the brushes are connected to three-phase resistances external to the motor, allowing for regulation of the motor start. This type of motor has been widely used in medium-power applications (above 50 HP), achieving
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