Electrical Engineering

RKVAH stands for Rated Kilo Volt Amperes per Hour. It basically refers to the reactive power and is commonly seen in industrial energy meters.

There is no one formula to guide construction of a coil used in a DC application. There are far too many different ones, and each has special considerations. Is the coil being used in an automobile to fire the spark plugs? Or in the solenoid to release the trunk lid of said automobile?

Check the wattage of the device that plugs into the adapter. If the device's wattage is lower that 25 watts then the answer is yes. If the device's wattage is higher that 25 watts then the answer is no.

Call your local utility.

Exciter controls the magnetic field in the generator system and controls the output voltage and/or current.

A capacitor that consists of thin dielectric layers interleaved with staggered metal-film electrodes; after leads are connected to alternate projecting ends of the electrodes, the assembly is compressed and sintered to form a solid monolithic block. -From http://www.answers.com/topic/monolithic-ceramic-capacitor?cat=technology

Yes, 100 MFD and 80 MFD capacitors will work in parallel, assuming they have the same voltage rating. The net capacitance will be 180 MFD.

Inrush is due to the saturation of the core of the transformer.

When the highside device closes to energize the transformer, it does not always do so right at a voltage peak. The transformer core B (magnetic field) will be 90 degrees out of phase with the applied voltage, so a peak voltage close is ideal. Once it is closed, the B will continue up and down 90 degrees out of phase with the voltage. Assuming there is no residual magnetic field (B starts at zero), it will be offset by the initial non - peak close. This offset in magnetic field will cause the core to go into saturation; depending on the core design it may be further or less into saturation on different transformers.

When the core saturates, large currents flow, and these currents (normally) have a high 2nd harmonic component which is used in protective relaying to restrain for inrush.

No, even though these are parallel circuits, the voltage drop across each device is not the same in house hold circuits, or anywhere, for that matter. Different devices pull different currents. A toaster, for instance, pulls many times what a light bulb pulls. Since wires do not have truly zero resistance, those differing currents result in different voltage drops across the wires that lead to the devices. That small voltage drop in the wires results in a different voltage drop across each device, even though the device/wire is connected to the same voltage source.

200 ~300 V

In 2001 the industry's products consisted of four primary product groups: fractional horsepower motors, integral horsepower motors and generators, land prime mover generator sets, and parts and supplies for motors and generators.

Electrical energy can be formed by solar, wind or hydro energy. This energy is transformed into electrical energy.

If it isn't a straight 6 you will have to find the casting number on the back of the block with the year and date. Most likely its a 283.

The failure mode of a capacitor depends to some extent on it's construction. Ceramic capacitors can crack and go open circuit whereas large electrolytic capacitors can gradually fall in capacitance as they age and exhibit an increase in leakage current or they can fail suddenly and short circuit - particularly if they have been stressed by a higher working voltage than they are designed for. Tantalum bead capacitors in particular had a reputation for shorting out. In some circumstances, the rush of current can remove the short circuit making it appear to be OK. Damage such as this will be cumulative and the capacitor may exhibit warning signs such as fluctuations in capacitance and leakage current prior to breakdown but in most cases once a capacitor fails, it fails permanently and suddenly and should be replaced. Most things cannot be fixed by "turning them off and then on again" - in fact this is the kind of thing which is most likely to stress components and the most likely time for them to fail.

Dave Baxter BSc Electronic Engineering

A think TANK is a concept where several people with differing specialties get together to solve a problem. Everybody brings their specialty and everybody gets to throw in an idea. There are no such things as "bad ideas", and everything gets a chance to be discussed. Think tank turns out to be a great way to solve a problem.

Closed-core and shell-core transformer (1885) The development of the electrical industry was hindered by the fact that the dynamo could only supply electricity trouble-free to short distances; to longer distances a large portion of electric energy got "lost" through overheated cables. The electrical engineers of that period were well aware that cheap electrical transmission could only be achieved by increasing the voltage. However, the experiments with DC (direct current) constantly ended in failure. Between 1884 and 1885 three engineers at the Ganz factory, Ottó Titusz Bláthy, Miksa Déri and Károly Zipernowsky developed a new current distribution system based on the use of the induction apparatus called transformer. Their joint patent described a transformer with no poles and comprised two versions of it, the "closed-core transformer" and the "shell-core transformer." In the closed-core transformer the iron core is a closed ring around which the two coils are arranged uniformly. In the shell type transformer, the copper induction cables are passed through the core. The core consists of iron cables or plates. Based on this invention, it became possible to provide economical and cheap lighting for industry and households.

to convert a 100mv to 1volt u will have to multiply it by 10. so u will need a stepup amplifier to do that. u can depend on am op-amp based amplifier to do it if u r allowed to use external supply, else u will need a transformer for the same.

Ashish.K

voltage drop deviding accure

yes

The fuse blowing is caused by an over current condition. Something is causing this. If it blows immediately when you turn it on there is likely a dead short in the circuit. Could be in the motor (most usual), in the heating element, in the control system or in the wiring itself. If you can get visual access to the underside of the dishwasher look for blackened areas. Also observe the underside when turning power on and look for a flash.

With a volt/ohm meter you can trouble shoot if you are comfortable working with electricity. With power off disconnect the AC black wire from the dish washer. When set on Ohms, with power off you should read an open circuit looking back to the supply side. If this is indeed open, that is what it should be. Then take a measurement of Ohms at the appliance between black and white wires. It will likely be reading close to zero Ohms, causing the short circuit.

You need to start disconnecting things like the motor from the supply and look for the input resistance to rise.

The original idea was to add 10% to the nominal voltage to allow for a voltage drop in transmission. The voltages used in power transmission follow that tradition so that common transmission voltages are 11, 33, 132 and 275 kV, although voltage drops of 10% would be against the regulations in most countries now.