Category: Electronics
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Basic Features of Crystal Oscillators
The crystal oscillators are implemented using the piezo-electric effect. This is actually realized when a voltage source is applied to a small thin piece of crystal quartz. The quartz crystal begins to change shape. This piezo-electric effect is the property of a crystal by which an electrical charge produces a mechanical force by changing the…
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Power MOSFET Motor Control
Because of the very high input gate resistance of MOSFETs, MOSFET’s fast switching speeds, and the ease at which they can be driven makes them ideal to interface with op-amps or standard logic gates. Nevertheless, care must be taken to ensure that the gate-source input voltage is correctly chosen because when using the MOSFET as…
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Metal Oxide Semiconductor FET (MOSFET)
The Metal oxide semiconductor FET (MOSFET) also known as the insulated-gate FET (IGFET) is similar to JFET but exhibits even larger resistive input impedance due to the thin layer of silicon dioxide that is used to insulate the gate from the semiconductor channel. This insulating layer forms a capacitive coupling between the gate and the…
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The Junction Field Effect Transistors (JFET)
The bipolar transistor has several disadvantages: it has low input impedance because of forward biased emitter junction, it has small high-frequency gain, it has considerable noise level and it is non-linear when |VCE| < 2V. Although low input impedance problem may be improved by careful design and use or more than one transistor, even so…
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Bipolar Junction Transistors (BJT)
By placing two PN junctions together we can create a bipolar junction transistor. In a PNP transistor the majority charger carriers are holes and typically germanium is favored for these devices. In NPN transistors the majority charger carriers are electrons; for this case, silicon is typically used. The thin and lightly doped central region is…
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Multiplexers and Demultiplexers in Digital Circuits
Multiplexers and demultiplexers are devices that route signals. A multiplexer also called a data selector takes one of several inputs and connects it to a single output. The input line that is connected is determined by the binary applied to the address lines. The diagram below shows a multiplexer with four input lines: The two…
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The Different Applications of Diodes
Diodes are used in many applications for example diodes are employed in reverse-polarity protection, used in voltage regulators, etc. We discuss these applications plus more in this article. Here are some of the different applications of diodes: Transient Suppression with Fly-back diodes Transient Protection When current flowing through an inductor is suddenly switched off, the…
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Semiconductor Diodes
A diode is a device that allows current to flow only in one direction. It is made from p-type or n-type semiconductors joined together. It has a depletion layer/p-n junction/potential barrier. How the depletion layer is formed The depletion layer is formed when a p-type and n-type are joined. The electrons in the n-type semiconductor…
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The Basic Principle of Operation of an Oscillator
An oscillator is the basic element of ac signal sources and generates sinusoidal signals of known frequency and amplitude. The main applications of oscillators are as sinusoidal waveform sources in electronic measurements. Oscillators can generate a wide range of frequencies (from a few Hz to many GHz) as per the application’s requirement. Even though, an…
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Optoelectronics
Optoelectronics deals with the study of all the electrically driven light-emitting devices, all devices which produce electrical effects when exposed to light, and all methods of conducting light through fixed pathways. Photometry units When a current is passed through a light source, a portion of the power dissipated appears in the form of light radiated…