Electronics Engineering

Impedance relays are used whenever over-current relays do not provide adequate protection. They function even if the short circuit current is relatively low. The speed of operation is independent of current magnitude.

Impedance relays monitor the impedance between the relay location and the fault. If the impedance falls within the relay setting, the relay will operate. The basic construction for impedance relays on which the principle of operation is easily explained is the balanced beam.

Low pass filters are used for various purposes in different areas.

A capacitor consists of two plates separated from one another by an insulator. These plates are normally thin foil and can be sandwiched around a very thin insulator and wrapped into a small package. Since there is an insulator between the plates, DC connected to the two plates cannot flow as long as you do not exceed the breakdown voltage of the insulator. AC current is a different story. Because the insulator is very thin and the effective plate area is relatively large, a negative charge building up on one plate causes electrons to be repelled from the opposite plate, and as the charge on the first plate reverses and becomes positive, the electrons in the opposite plate are attracted back again. This results in a matching alternating current flow on the opposite side of the capacitor.

actually what happens, capacitor provides a reactance to current.

Xc= 1/ (2*pi*f*c) ,where pi=3.14, f=frequency , c=capacitance vaue

as dc current is independent of frequency so Xc becomes infinite so dc current gets infinite resistance. so it is blocked

ummmmm... put it in series.

[1/(1+Ab)] is the expression for sensitivity...

2(frequency deviation+signal frequency)

No, the flux capacitor is at this moment in the realms of Science fiction as far as we know.

It can connect 2 pins with a very high resistance and with a quite low resistance, depending on the voltage of the corresponding input pin.

If your multimeter has a transistor check (hfe), then place the Collector,Base& Emitter in the CBE port of multimeter.

Turn the shaft to Diode mode.

If the value is zero,skip that transistor.

You can use the forward resistance of each junction, using the ohms range or diode check function.

Put the leads on the Base and Emitter, then reverse the leads. You should get about 600Ohms forward bias and open circuit (infinity) reverse bias.

Do the same between the Base and Collector. You should get the same results.

Finally put the leads between the Collector and Emitter. You should get open circuit both ways around.

Be aware that some high power transistors have a diode across the Emitter and Collector.

These tests will just be a basic 'go - no go' test. It may pass this test and yet still not perform fully.

You can see obvious faults, like a dead short both ways on each junction or across the Emitter to Collector.

Harvard Law School is the obvious answer, but if you want something that is useful, I would recommend electronics with a specialization in RF technology.

Not exactly. However flip flops of all types were originally called trigger circuits or simply triggers.

In switching power supplies.

115 is the RMS voltage. The actual voltage is a sine wave from -167 to +167 relative to ground. RMS stands for root-mean-square, and it a way of saying that 155 Volts of DC would do the same work on the same sized load.

There can be up to 3 phases, and they are the sine wave, shifted by a part of the curve. In most houses, there are 2 phases, and the voltage to ground for each is 110 to 120 V RMS. The voltage between the 2 is 230-240VRMS.

3 phase gets very complex. Each phase is 115 to ground or neutral. 3 PHASE 115V AC EACH PHASE IS 120 DEGRES PHASE SHIFTED THE EFFECTIVE VALUE IS .639 X 115 THE PEAK VALUE OF PHASE IS 1.41X RMS VALUE.

Its a big flexible rubber chicken.

Biasing is necessary in a transistor circuit to keep the transistor working. Without proper biasing, the circuit will fail

Hewlett Packard

A: A mother board contains many cards and the communication of these card is essential. What he is looking for a fast I/O BUSS and after that for potential slot expansion.

no actually dc current is more dangerous than ac because dc is a direct current and has no current zero condition ,which is very dangerous and do not leave us if we get shock while ac current leave us when we get shock

A low bandwidth signal does not have more power.

An average yearly salaryÊfor specialistsÊin the forensic portion of this field can earn almost $100,000 USD. Other areas such as those related to speech average about $45,000 USD for each year.

cheese

Absolute and Relative Error

Absolute and relative error are two types of error with which every experimental scientist should

be familiar. The differences are important.

Absolute Error: Absolute error is the amount of physical error in a measurement, period. Let's

say a meter stick is used to measure a given distance. The error is rather hastily made, but it is

good to ±1mm. This is the absolute error of the measurement. That is,

absolute error = ±1mm (0.001m).

In terms common to Error Propagation

absolute error = Δx

where x is any variable.

Relative Error: Relative error gives an indication of how good a measurement is relative to the

size of the thing being measured. Let's say that two students measure two objects with a meter

stick. One student measures the height of a room and gets a value of 3.215 meters ±1mm

(0.001m). Another student measures the height of a small cylinder and measures 0.075 meters ±1mm (0.001m). Clearly, the overall accuracy of the ceiling height is much better than that of

the 7.5 cm cylinder. The comparative accuracy of these measurements can be determined by looking at their relative errors.

relative error = absolute error

value of thing measured

or in terms common to Error Propagation

relative error = Δx

x

where x is any variable. Now, in our example,

relative errorceiling height = 0.001m

3.125m

•100 = 0.0003%

relativeerrorcylinder height = 0.001m

0.075m

•100 = 0.01%

Clearly, the relative error in the ceiling height is considerably smaller than the relative error in the

cylinder height even though the amount of absolute error is the same in each case.

Relaxation oscillators just requie a certain voltage range in which to operate, so most any schematic for one will work, providing you have enough D cells to be able to supply the proper voltage.

Buy one.