What is the function of a power source in an electrical circuit?
A power supply is an electrical device that supplies electric power to an electrical load. The primary function of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load.
Why are resistors used in circuit boards?
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
What is the difference between a diode and a resistor?
A diode is a type of electrical device that allows the current to move through it in only one direction. A resistor is an electric component that is used to provide resistance to current in the circuit. They are mostly used to produce heat or light.
Can a diode act as a resistor?
A diode can act as a resistor for small signal AC circuits. In fact, it can act as a variable resistor. The dynamic resistance of a diode depends on its forward bias. The resistance is for very small excursions above and below this bias point.
What is the principle of Zener diode?
A Zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.
What is the difference between a diode and a transistor?
One of the major difference between the diode and the transistor is that the diode converts the alternating current into direct current while the transistor transfers the input signals from the low resistance circuit to high resistance circuit.
Can you use a transistor as a diode?
Since a bipolar transistor is essentially two diodes, it can function as such. However, since bipolar transistors are not designed to be used as diodes, using them as diodes might cause a problem in terms of current and other ratings. Use dedicated diodes for typical diode applications instead of bipolar transistors.
When would you use a diode?
The key function of an ideal diode is to control the direction of current-flow. Current passing through a diode can only go in one direction, called the forward direction. Current trying to flow the reverse direction is blocked. They’re like the one-way valve of electronics.
Can we use two semiconductor instead of a diode?
No. Two back to back diodes is NOT a transistor. The special property that makes a PNP or NPN sandwich a transistor rather than just two diodes is that the base layer is very thin. In semiconductor physics terms, there aren’t two separate depletions regions in the base.
How can a transistor be used as a diode?
For example, a 3904 type transistor will have <1pA of reverse leakage using the Base Emitter junction. However, it turns into a zener diode at around 6.8V. Works great for 5V and lower voltage logic circuits. Higher current and reverse voltage is achieved by using the Base as anode and the collector as the cathode.
What does a diode do?
A diode is a semiconductor device that essentially acts as a one-way switch for current. It allows current to flow easily in one direction, but severely restricts current from flowing in the opposite direction.
What is the difference between diode and thyristor?
A diode is a two-layer device having a p and an n region. While a thyristor is a four-layer semiconductor device formed by alternate arrangement of p and n type material. Due to 2 layers in diode, there exist a single junction in case of diode. Whereas due to 4 layers, the thyristor has 3 junctions.
Where is thyristor used?
Thyristors may be used in power-switching circuits, relay-replacement circuits, inverter circuits, oscillator circuits, level-detector circuits, chopper circuits, light-dimming circuits, low-cost timer circuits, logic circuits, speed-control circuits, phase-control circuits, etc.
How does a thyristor work in a circuit?
Thyristor are current operated devices, a small Gate current controls a larger Anode current. The thyristor acts like a rectifying diode once it is triggered “ON”. Anode current must be greater than holding current to maintain conduction. Blocks current flow when reverse biased, no matter if Gate current is applied.
Why is germanium not used for SCR?
Ability to withstand at high temperature: silicon crystals have capability to withstand at higher temperature compare to germanium crystals . So if leakage current is produced in SCR it heats up the device then silicon crystals can withstand but not germanium crystals.
Which is better silicon or germanium?
The structure of Germanium crystals will be destroyed at higher temperature. However, Silicon crystals are not easily damaged by excess heat. Peak Inverse Voltage ratings of Silicon diodes are greater than Germanium diodes. Si is less expensive due to the greater abundance of element.
Why silicon is used in Zener diode?
Silicon does not get damaged easily due to excess heat. Variation of Ic0 with temperature is not much hence thermal stability is maintained. Also reverse voltage of silicon diode is higher. Therefore silicon is the most used material for manufacturing diodes.
What is the difference between silicon and germanium?
Each has four valence electrons, but germanium will at a given temperature have more free electrons and a higher conductivity. Silicon is by far the more widely used semiconductor for electronics, partly because it can be used at much higher temperatures than germanium.
Why Germanium is a semiconductor?
Germanium atoms have one more shell than silicon atoms, but what makes for the interesting semiconductor properties is the fact that both have four electrons in the valence shell. As a consequence, both materials readily constitute themselves as crystal lattices. Substituted atoms alter the electrical properties.
Why is si a semiconductor?
A Silicon crystal lattice has a diamond cubic crystal structure in a repeating pattern of eight atoms. Each Silicon atom is combined with four neighboring silicon atoms by four bonds. Silicon, a very common element, is used as the raw material of semiconductors because of its stable structure.
What is the use of silicon and germanium?
Silicon-germanium is an important material that is used for the fabrication of SiGe heterojunction bipolar transistors and strained Si metal-oxide-semiconductor (MOS ) transistors for advanced complementary metal-oxide-semiconductor (CMOS ) and BiCMOS (bipolar CMOS) technologies.
What is germanium used for?
In addition to its applications in electronic devices, germanium is used as a component of alloys and in phosphors for fluorescent lamps. Because germanium is transparent to infrared radiation, it is employed in equipment used for detecting and measuring such radiation, such as windows and lenses.
Are silicon and germanium metals?
A series of six elements called the metalloids separate the metals from the nonmetals in the periodic table. The metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium. These elements look metallic; however, they do not conduct electricity as well as metals so they are semiconductors.
Which has higher resistivity Ge or Si?
Pure germanium has a resistivity of 60 ohm–centimeters. Pure silicon has a considerably higher resistivity, in the order of 60,000 obm-centimeters.
Which conductor has highest resistivity?
Resistivity and Temperature Coefficient at 20 C
| Material | Resistivity ρ (ohm m) | Conductivity σ x 107 /Ωm |
|---|---|---|
| Silver | 1.59 | 6.29 |
| Copper | 1.68 | 5.95 |
| Copper, annealed | 1.72 | 5.81 |
| Aluminum | 2.65 | 3.77 |
What is the resistivity of germanium?
Table of resistivity for common materials
| Table of Electrical Resistivity for Common Materials | |
|---|---|
| Material | Electrical Resistivity at 20°C Ohm metres |
| Germanium | 4.6 x 10-1 |
| Iron | 1.0 x 10-7 |
| Lead | 1.9 x 10-7 |
Is arsenic a donor or acceptor?
Elements like phosphorus, antimony, bismuth, arsenic etc. are donor impurities. While boron, gallium, aluminium etc. are acceptor impurity atoms.
Is indium a donor or acceptor impurity?
Antimony, Phosphorous and Arsenic are 15 group element, having 5 valence electrons. Thus these are donor impurities. Whereas Indium is a 13 group element, having 3 valence electrons. Hence Indium is an acceptor impurity.
Why N type semiconductor is called donor?
Donor impurities donate negatively charged electrons to the lattice, so a semiconductor that has been doped with a donor is called an n-type semiconductor; “n” stands for negative. Free electrons outnumber holes in an n-type material, so the electrons are the majority carriers and holes are the minority carriers.