Electronics Engineering

unit of internal resistasnce is ohms too. V = I(R+r) V voltage across the circuit I current in the circuit R external resistance r internal resistance unit of internal resistasnce is ohms too. V = I(R+r) V voltage across the circuit I current in the circuit R external resistance r internal resistance

In a circuit, either in Parallel or in Series with other components.

Ohm's law gives the relationship between current, voltage, and resistance. The law states that I=V/R, where I is current, V is voltage, and R is resistance.

Source: university digital fundamentals

An electromotive force is the potential difference developed by a voltage source, and is necessary to cause current to flow through a circuit. Strictly-speaking, it is the open-circuit potential difference of a battery, generator, etc. An alternative definition is that an e.m.f. is equal to the sum of the voltage drops around any closed loop, including any internal voltage drop.

by growing an array of different color LEDs and driver transistors on a glass sheet. each pixel gets a square array of 4 LEDs: red, green, blue, green. the glass sheet is then wired to the TV circuits.

the glass sheet (screen) is effectively a super giant IC.

another name for diode is "pn" junction.

Short answer, no.

Not so short answer, it depends on the battery's chemistry. In all cases, you're not going to charge it completely no matter the chemistry, but you might charge it anywhere from nothing to ~75% depending on the chemistry and the 6 volt charger's top voltage(It's not 6 volts! If it's a lead charger, you might expect a top voltage of ~6.8 volts). Also, you want to make sure the charger's amperage doesn't exceed the battery's charging current's ability or you might overheat the battery and destroy it.

In a longer answer, it is possible to convert a 6 - 7 volt supply to 8-9 volts with a "boost up" converter but that's either going to require buying the device or making it yourself. Even if you we're to do that, you need to make sure the battery's chemistry's safe limits aren't exceeded. NiMH, for example, has a quick downtown in its voltage near the end of its charging, and if the charging isn't cut-off there, the battery will keep absorbing charge until it overheats and explodes. another comment: yes if it fits into the device normally though it would take a little longer to charge

The primary difference is that the microwave signal is of a much higher frequency than an AM signal, if that AM signal is speaking to AM broadcast radio. In general, AM, or amplitude modulation, is not generally used as a modulation technique on microwave frequencies because there are other ways to put a signal on a microwave carrier that allow more information to be transmitted. AM is "low frequency" RF, while FM is a bit higher on the radio frequency spectrum, and microwaves are further on up.

if it is a three phase motor it can be run an the single phase mains but it woild require a hand start in either direction, if you put a capacitor on line two and three and the live and neutral on line one and two then it should work

In a parallel circuit the failure of one bulb reduces the light of that one bulb. In a series circuit the failure of any bulb causes all bulbs to stop producing light because the circuit itself fails. A break in a series circuit stops the current flow to the whole circuit. A break in a parallel circuit stops the flow only in that parallel branch, not the whole circuit. This independence from system loss by one failure is a parallel advantage.

An analog meter will respond to linearly as current is present . digital meters cannot do that not until the conversion is complete. in essence an analog meter is human friendly as compared to a digital meter. both have their places in applications.

Radio Detection And Ranging

The true advantage of digital wattmeters over electromechnical wattmeters is the cost to operate the meter. Also, virtually all digital meters can emitt a radio signal to forward the power useage for a certain time period to a recording device. This means that a utility can drive around the block rather than manually walking up to each house and recording the power usage every month. The best electromechanical wattmeter has a power consumption of 24Watts. The leading Centron digital meter has a starting power of less than 5Watts. The operating power consumption for electromechanical meters is also more than that of digial meters. Loss of electromechanical meters is ~ .7Watts Loss of digital meters ~.5Watts The display could be considered an advantage also because people who are not trained in reading a scaled meter can read a digital meter easily, however, if they aren't trained in reading a meter they most likely will not understand what they are reading anyway.

Phase-shift oscillator

Armstrong oscillator

Cross-coupled LC oscillator

RC oscillator

As with all things, temperature does change things.

With amplifiers, the changing temperature in the power transistors running the speakers can become a ruining experience.

The louder you play, the more heat is generated in these transistors.

The hotter they get, the less current do they stand.

Some transistors may be able to push forward 160-200 Watts of music at 25 degrees Celsius. As they get warmer, their level of 'performance' must be put down according to temperature. At 50 degrees Celsius, they may be able to withstand 120 Watts of music. at 100 degrees, they may only be able to give 60 watts of music. At 120 degrees, they are close to the transistors internal breakdown temperature and only 10 watts of music may be destructive.

Good cooling of power transistors in amplifiers help avoid destroying an amplifier but it does not fully solve the problem of temperature drift.

A mayor issue is that an amplifier that does not consume power (like when no music is played) will not be able to start instantaneously to play good music. We will experience a delayed action that is very well audible. In a class B or a class AB amplifier, this is fixed by always having the amplifier to work, they just work on making silence, constantly having a small current over the power transistors.

This small current however is dangerous for the transistors. The transistors try to 'amplify' and in this process, all of this current is transformed into heat. The big problem is that as transistors get warmer, their ability to amplify increases.

A small current of 25 mA may generate 2 Watt of heat at 25 Degrees Celsius, but at 75 Degrees Celsius, the same small current of 25 mA may generate 20 Watt of heat. The process is self destructive. As transistors heat up, they generate more and more heat and get more and more out of the little start current of 25 mA. In the end, they burn up internally.

It is important that the small current decreases with the increase of temperature, otherwise your amplifier will quickly be destroyed. This can happen in a matter of minutes only, even with quite a decent cooling profile and even a fan attached.

In a series circuit, if you open a bulb, current loop will be broken. So, current cannot travel all the wayback, hence no output. But in a parallel circuit, current will be only shared with parallel circuit, but the loop remains closed even if you remove the bulb. So, no change occurs.

PN means pressure rating of a pipe....PN is just a symbolic representation....

When a circuit is in off condition then it is called an open circuit..

FET is abbreviation of Field Effect Transistor. This is a transistor in which current is controlled by voltage only and no current is drawn. It is a high input impedence device and is used in computers, telecommunication and control circuits. This transistor is better in certain parameters as compared to BJT, that is Bipolar Junction Transistor.

The Quickest easiest way is going to be with a battery or jumper pack. Ground the body and touch the two terminals one at a time with the positive lead from a battery or jumper pack. One makes it turn the other makes it stop, the one that makes it turn is the starter or armature, the one that does nothing is the field. To go one step further to see if you are getting a good generator start it to full rpm and remove from the armature terminal and quickly touch the field terminal if the charging part is working correctly it should forcibly stop the pulley from rotating, you will notice a difference from just letting it spin to a stop.

The 555 timer is commonly used in IC electronics and in electronic circuits. In the monostable multivibrabor mode, the 555 works as a pulse generator. In astable mulitvibrator mode, the 555 is free running, and goes back and forth between frequencies.

EHV and VHV substations tend to have a signature hum; this is due to small electrical arcs. This is normal. Most of the time this will not be audible on VHV and EHV power lines. If you are hearing this from the power line, it could be bad and the utility may want to know. It shouldn't be a risk to you, however the hum may be resulting from arcing, which can be fairly high frequency, which can mess with electronics's signals such as cell phones and radio (won't damage them, just bad reception).