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What are the difference between carrier signal modulating signal modulated signal baseband and passband?
carrier signal- use for the purpose of conveying information. modulating signal- causes variations in some characteristics of carrier signal. modulated signal - carrier signal after altration in its characteristics is called modulated signal. example- if you want to see an object (suppose it is an modulating signal),you need light(light is carrier signal) and when light will reflect on object you will be able to see if (that is modulated signal)
Why you need modulation?
It might be helpful to have a working definition of modulation before making a statement as to why it is needed. In fact, with an understanding of what modulation is, it will be obvious why it is included in electronic communications.Modulation is the "message" or the "intelligence" that is impressed on a radio frequency (RF) carrier. When we transmit a signal, we generate a carrier frequency, and then we modulate it. We "add" the message or the information we wish to transmit by modulating the carrier in some way. There are at least a dozen different modulation schemes ranging from simple to real head scratchers. They either modify the amplitude, the frequency or the phase of the carrier. Let's look at a few.The simplest modulation technique is taking the transmitted signal and turning it on and off. It is "keyed" to send a series of pulses. Morse code uses on-off keying. In this method of modulation, no modification of the RF carrier signal itself is made. It is simply switched on and off. (It could be looked at as amplitude modulation with the carrier either at zero amplitude or at "maximum" amplitude with nothing in between.) A series of pulses can be transmitted. With Morse code, a short "on" period will send a dot or "dit" out. If we extend the "on" period a bit, we can send a dash or "dah" out. Nothing real sophisticated here, but basic and effective communication. There are obvious limits to how fast information can be transmitted with this modulation scheme. (But don't tell the hams who still use it!)Most of us are familiar with AM radio. AM is amplitude modulation. The amplitude of the RF carrier is modified to modulate it. The amplitude of the modulating signal will determine the amount that the amplitude of the carrier is changed. (The volume of the modulation determines how much the amplitude of the carrier is changed. The frequency of the modulating signal determines the rate of change of the amplitude of the carrier. (The frequency of the modulation determines how fast the amplitude of the carrier is changed.). The frequency of the carrier is held constant through all this.How about FM? In frequency modulation, the amplitude of the carrier is constant. It's left alone. But the frequency of the RF carrier is changed. It is swung above and below where it sits (it's assigned center frequency) at a rate proportional to the frequency of the modulating signal, and at an amount proportional to the amplitude of the modulating signal. In FM single sideband, the carrier frequency and the frequencies above the carrier are transmitted and the frequencies below the carrier are suppressed (upper sideband transmission). Or the frequencies below the carrier are transmitted with the carrier and the upper frequencies are suppressed (lower sideband transmission). In conventional television, the video signal is single sideband, suppressed carrier. It's like "regular" upper sideband transmission except the carrier signal is suppressed. Sideband transmission "saves" space on the RF spectrum. And it works because we really don't need "all" of the FM signal to demodulate the signal at the receiver.Other forms of modulation become more complex. CDMA (code division multiple access), TDMA (time division multiple access) and other methods are used in cell phones to modulate the carrier so the digital data stream can be impressed on the carrier.Modulation is the addition of intelligence to a carrier signal. It's the message. Modulation is necessary because the point of communication is getting the message through.A Simple answer:Simply this... Any communications medium: e.g. Free space - radio waves, Air - Sound waves or radio waves, Optical Fibre - Light, Copper Wires Electrical Anergy (with frequency limits of the copper wire construction) is made for a certain type of signal. But if the signal we want to send is not compatible with the medium, then it does not travel well.Modulation changes the information we want to send from it's original form, into one that is more compatable with the medium we are trying to use.For example, your computer speaks digital over a TCP/IP LAN which requires CAT 5 or better rated cables,, but to connect to your internet service provider (ISP), you need to send the signal over the wires of the telephone company (made for voice tones). To make this connection, and ADSL modem (modulator/demodulator) is used to convert the data into audio tones, which pass over the telephone line, and at the far end are converted back to digital to join the service providers network. in the reverse direct the ISP does the same, and the signals are de-modulated, back to data for your network.Or in simple terms, Its about best use of the medium. Everything else is just a away of doing it. And there are a lot of possible ways to choose.
What is light activated SCR?
A light-driven semiconductor device that prevents current flow in either direction until it receives a signal.
What is amper in traffic signals?
Amber in the traffic signal means caution. Generally, it is best to stop on an amber light.
Why are light fixtures made of non combustible material?
Because traditional incandescent light bulbs generate significant heat that could cause flammable materials to ignite.
What are the difference between carrier signal modulating signal modulated signal baseband and passband?
carrier signal- use for the purpose of conveying information. modulating signal- causes variations in some characteristics of carrier signal. modulated signal - carrier signal after altration in its characteristics is called modulated signal. example- if you want to see an object (suppose it is an modulating signal),you need light(light is carrier signal) and when light will reflect on object you will be able to see if (that is modulated signal)
Is light the only signal carrier in optical fibers?
yes
Brake lights do not work all the time replaced brake light switch?
If you have the same bulb for brake and signal, brake light power needs to be interrupted by the signal lights, The brake circuit has to go through the signal light switch so the problem could be there.
Toyota camrey 1998 why wont my signal lights work?
Check the signal light fuse, the signal light relay, and the signal light switcher.
Why does your left brake light burn at all times?
It could be the turn signal switch.
Where is the turn signal on a 2002 Pontiac Sun fire?
We could use a little more info here. The turn signal light? In front? In the rear? The turn signal switch?
What could be the problem if its not the front parking bulb on Mercedes c180?
If you are getting an indicator of a burned out light, but don't see a burned out light, it must be a turn signal light. On a Mercedes, you'll actually get a "burned out light" indicator if the turn signal is not working.
What is the 'carrier' in the EM spectrum?
The carrier could be light, radio waves, almost any of the wave energies in this spectrum that are not hazardous to life. When used to convey information they are called carriers because one or more characteristics of the wave are varied to encode the information. One of the simplest forms of encoding or modulating a carrier is amplitude modulation which is used to make radio frequencies carry sound. The amplitude of the radio frequency signal is varied in step with the sound.
How do you fix a turn signal when the hazard lights blink left turn signal blinks but when using right turn signal it just stays solid.?
It means that a light bulb is out on the side where the light solid (not blinking) it could be in the front or rear of the vehicle.
Will a bad signal light flasher stop the brake lights from working on a 1983 dodge d 150 pick up?
Assuming the signal lights still work, no. But a bad brake light switch or a blown brake light fuse could.
Why would my ABS and check engine light and left turn signal light come on only when I turn my headlights on?
You have a faulty ground to one of the tail light bulbs and there is a reverse current flow back through the brake light circuit. It could be either front or rear turn signal light.
Why doesn't your turn signal flash or light up?
Check the signal relays and fuses under the hood. Because of the battery is not sufficient to light up the signal light.
