Electronics Engineering

line transformation ratio would be the turns ratio (ie voltage ratio), while the phase transformation ratio is most probably the phase shift introduced by a 3 phase transformer.

thyristor can be turned off only by reducing the anode current belaw a certain value called holding current

by abdullahi yusuf gedi

2 bit comparator = 1bit magnitude comparator +1 bit magnitude comparator

if A>B =A(~B)(B bar);

if A<B = ~A.B;

A==B = AB + (~A)(~B);

block of instruction shown above is for 1 bit comparator

means if A>B ==true then High bit is set on (A>B) output.

if A<B true then high bit is set on (A==B) output,

If we cascade two 1 bit comparator then we can design 2-bit comparator...

In monostable multivibrators Circuits (quasi stable state) is one of two states, stable state and quasi stable state which is invoked by an external trigger and it will stay there for value determined by time constant.

Yes DC is periodic with zero frequency........and undefined fundamental time period To........

When we apply reverse bias voltage to input and output sides of a BJT, then the width of the depletion layer at emitter-base and base-collection got increased. Due to which the effective base width got decreased. This phenomenon of reduction in the base width is called Early effect.

And if we go on increasing the Reverse bias voltage then at a time instant the width of the base becomes zero and this effect is called punch through effect and that reverse bias voltage is called punch through voltage.

the voltage standing wave ratio is defined (1+p)/(1-p), where p is the the reflection coefficient magnitude. p = 1 for an open circuit, therefore the VSWR will approach infinite.

Advantages: CRC is simple to implement in binary hardware, Mathematical analysis of CRC is very simple, and it is good at detecting common errors caused by noise in transmission.

Disadvantages: CRC is not suitable for protecting against intentional alteration of data, and overflow of data is possible in CRC.

Impedance is a vector sum using the formula Z = square root (XL2 + R2); where Z = impedance, XL = inductive reactance, and R = resistance. Therefor the formula for a circuit where XL = 64ohm's and R = 36ohm's is Z = square root(642 + 322); Z = 71.6ohms.

A printed circuit board. abbrev- PCB. A PCB is thin copper attached to a non-conductive material.

No, a printed circuit board is not a semiconducting material. Integrated circuits are created on a substrate, usually silicon or sapphire.

By Ohm's law, resistance is voltage divided by current, so the resistance of a light bulb can be measured by observing the voltage across it simultaneously with observing the current through it.

Interestingly, the hot resistance is significantly different that the cold resistance, so measuring resistance with an ohmmeter will not give a meaningful resistance.

This is because the resistance of a light bulb has a positive temperature coefficient. Take a typical 60 W 120V light bulb, for instance... Its cold resistance is about 16 Ohms. Calculate current and power at 120 V and you get 7.5 A and 900 W. The truth is that at 60 W, the bulb pulls 0.5 A and has a resistance of 240 Ohms.

Crossover distortion is a type of distortion which is caused by switching between devices driving a load, most often when the devices (such as a transistor) are matched. It is most commonly seen in complementary, or "push-pull", Class-B amplifier stages, although it is occasionally seen in other types of circuits as well

Most digital articles/schematics will display frequency as lowercase "f", hand written articles and some CAD software will display frequency with the more accurate lowercase "f" with hook this symbol can be generated in HTML with &#0131; or (in windows) by pressing alt+0131

Power, P, is current, I, times voltage, E. (P = IE)

Not knowing one of voltage, E, or current, I, you can apply ohm's law ...

E = IR or I = E/R

... and come up with variations ...

P = I2R

P = E2/R

It doesn't.

In a series circuit, the largest voltage drop occurs across the largest resistor; the smallest voltage drop occurs across the smallest resistor.

R = resistance = rho * L / S

rho is resisitivity in [Ohm m], it depends on the material (Copper: 2e-8 [Ohm m])

L is wire length [m]

S is wire cross section [m]

EDIT: for high frequencies, you may also wanto to take sink effect into account (~MHz)

1. The energy band gap between the cathode and anode is too small to generate photons of higher energy than far IR.
2. Silicon is opaque to visible light (and even IR).

Electronic bottleneck refers to the inability of electronic devices to process optical data at very high speeds. The term is used mostly when trying to justify the need to process ultra high speed data using all-optical devices without the need for optical-electrical-optical conversion.

Unidirectional TVS: A TVS device with asymmetrical

current versus voltage (I−V) properties. A unidirectional

TVS is best suited for protecting circuit nodes whose signals

are unidirectional or always above or below the reference

voltage, usually ground.

Bidirectional TVS: A TVS device with symmetrical I−V

properties. A bidirectional TVS is best suited for protecting

electrical nodes whose signals are bidirectional or can have

voltage levels both above and below the reference voltage,

usually ground

Never because he can't deal with his own sexuality and has a great deal of self loathing.

Fiber optic terminal box generally refer to the box shape fiber optic management products used to protect and distribute the optical fiber links in FTTH Networks. Usually the fiber optic box includes the fiber optical patch panels and fiber optic terminal box. Fiber optic patch panel is bigger size, fiber optic termination box is smaller. Actually there are too many fiber optic boxes and fiber management devices, they are hard to count the types, many manufacturers will make the fiber optic boxes according to their own design and they may give the fiber optic boxes different names and model numbers.

Many mutlimeters have this capability. You'll probably want a digital multimeter. If you do a good search, this should be easy to find. You'll need to read through the specifications carefully to make sure you find one that gives the level of accuracy you're looking for. the more accurate it is, the more you'll pay.

this always used in inverters and UPS As in standby UPS And line interactive UPS ,the output frequency must be always track the input frequency as it supply the load from utility in standby mode, for any change that will affect the load .

as example the frequency of the utility was with permitted values say 58Hz and suddenly the main power cutout, so UPS must be on same frequency so when convert to backup stored power mode ,the load doesn't affected and power continue to supply the load from the batterys through inverter , so output frequency must be always synchronized to utility frequency (mains) in case of any fault happened, hope i answered your question.

Sherif Salah

R & D Engineer at Arrow Electronics

Egypt