Electrical Engineering

since i doesnt take any feedback and the bread pops out as soon as the time is over. whether the bread was toasted or not is not seen, hence it is open loop.

to reduce core reluctance..

If the synchronous motor is single phase then there are two slip rings & if this motor is three phase so the slip rings are three in number.

Correction;

I have never seen a single phase synchronous motor. It would cost more that it was worth.

A synchronous motor has a separately excited field. If the excitation comes from a stationary DC source it has 2 slip (collector) rings.

A brushless induction motor has no slip rings because the exciter armature rotates and so do the rectifiers.

A permanent magnet motor, used with variable frequency drives, is another type of synchronous motor that has no slip rings.

A three phase motor with 3 slip rings is a Wound Rotor motor. Wound rotor motors are variable speed motors that were used for such applications as bridges and cranes before variable speed drives.

The rated voltage of a motor listed on the nameplate is called the terminal voltage. This indicates the actual voltage on the motors terminals at which at which the manufacturer designed to operate. Whereas, Nominal voltage is the design or configuration voltage of the electricity distribution system.

we know that ratio of holding current to latching current in scr is 0.4.

The "effective" value of an alternating voltage is generally considered to be the RMS (Root-Mean-Square) value. The best way to measure that is with a True RMS voltmeter.

Lacking that, if the voltage is sinusoidal, you can use an older style peak measuring voltmeter that estimates RMS value by dividing internally by the square root of 2. Any other shaped waveform will be measured incorrectly, depending on the amount of deviation from sinusoidal. (Square wave is the best example of error in this case - RMS and peak should be the same, but they won't read the same except on a True RMS voltmeter.)

Follow the related link, below, for detailed in information.

That's like asking how many meters in a liter.

Ampere and Volt are two DIFFERENT measurements.

Ampere is how much electricity you are using, while volts are how much pressure the electricity is under(Think water).

If you want to figure out how many amperes your appliance is using you could use this formula: P=UxI (Watt=Volt x Ampere) or U=RxI(Volt=Resistance x Ampere).

Sure - an unconnected power supply of any kind - a battery is + at one end and - at the other.

you run the voltage up to 2x the operating voltage + 1000v

this detects exposure to moisture and pinholes in insulation

if it cant pass a hi-pot test chances are it wont pass signals reliably either

The auxiliary contact is to be utilized for interlocking of another relay or contactor or indication signal from another equipment.

Primary current is a flow to be measured that cannot be safely passed through the measuring device. A current transformer is used to provide a lower level, secondary current that can be passed safely through the measuring device. Primary current is measured as a secondary current, multiplied by the turns ratio in the current transformer.

60HZ

Turn on all the electric divices in a circuit!

voltage sensor, alarm circuit, Pulse generator, counter,

register and timing circuits.

Zener diodes attempt to keep terminal voltage constant. If the load is fairly small, a single zener diode can be used for this purpose. If the load is large enough that the zener cannot hold the voltage within desired margins, I suggest using the zener to control the base of a power transistor; the emitter or collector (depending on transistor type) will be used as the output to the load.

There are different national and international standards for symbols and abbreviations. You will need to check out the national standards for the drawings you are referring to.

Depends upon the capacitance. The time of holding charge can analyse by transient analysis.

This is a class of current transformers, and is a fairly low class. This has to do with what kind of burden can be placed on the secondary. A general rule is a C200 current transformer can supply ~200 volts at full ratio to its' secondary. If the burden (the CT resistance + cable resistance + relay or instrument resistance) times the maximum expected current is higher than 200 volts, the CT is likely to saturate.

During multiple fault events, a CT may keep some magnetizing current causing CT saturation to be higher on a reclose event. Typically CT's are sized and their ratios are chosen to minimize saturation when feasible.

The ampere-hour rating of series connected batteries is the same as that for one battery, so the ampere-hour rating of four 65 Ah batteries in series is still 65 Ah.

The reason for this is Kirchoff's current law - the signed sum of the currents entering a node is zero - or - the current at every point in a series circuit is the same.

The purpose of a voltmeter is to indicate the potential difference between two points in a circuit.When a voltmeter is connected across a circuit, it shunts the circuit. If the voltmeter has a low resistance,it will draw a substantial amount of current. This action lowers the effective resistance of the circuit andchanges the voltage reading.

a substation go to http://www.chacha.com/question/what-are-small-buildings-containing-Transformers-and-electrical-equipment is where i found the anser

The maximum supply voltage per the data sheet is 5.25 volts. This is a common max for TTL type IC's.

Not all the loads in an electrical installation operate at their nominal power all the time. A good example are the plug sockets which are rarely used at their maximum output (which in this case would be the limit of the protective fuse of 10 or 16 amps). So, in order to get a realistic image of the power demand, there is also a simultaneity factor applied. But each tipe of consumer can have its own factor depending on the tipe of load, ratio of its usage and also on the interpretation of the engineer. Coming back to the example with sockets, usually a coefficient of 0.2 is taken into consideration but for other loads that are operating at their nominal current/power(like lighting) a higher factor up until 1 would be assumed.

By multiplying the nominal power with simultaneity factor you will get the power demand.