Electronics Engineering

SL100

lED, or light emitting diode, chips an others

df

LEDs, known as light emitting diodes, are comprised of two lead semiconductor light sources. Laser transmitters, also known as laser diodes are comprised of an electrically charged semiconductor laser.

Summary: An FM transmitter has an oscillator that generates the carrier RF signal. Frequency modulation takes place at the oscillator stage. The modulated signal is then sent through some filters and then finally amplified by a class C power amplifier, and then delivered to the antenna. An FM transmitter has an oscillator that generates a carrier signal on a desired frequency. But something like a voltage controlled oscillator is used so that the oscillating frequency can be changed by a modulating signal. When there is no modulation, the oscillator runs at it assigned frequency (called a center frequency). The voltage that is controlling the frequency at which it is running is constant. By applying the volage of a modulating signal to that "controlling" voltage, the frequency of the signal can be caused to vary above and below its assigned center frequency in a way that is directly proportional to the modulating signal. It is shifted above and below its assigned center at a rate proportional to the frequency of the modulating signal and at an amount proportional to the amplitude of the modulating signal. This takes up a bit of what is called bandwidth on the electromagnetic spectrum. The modulated FM signal appears as a "group" of frequencies around that center frequency with the sub-group of frequencies about the center being called the upper sideband, and that sub-group below the center being called the lower sideband. Almost all of the power in the generated signal is carried in these sidebands. This RF signal is them amplified by a high power RF amp, and the (now) high-powered FM signal is then sent via a transmission line to an antenna, from where the signal radiates into space. A link is provided to the Wikipedia article on FM modulation. Surf on over and check out the drawings and the little "moving pictures" to get a handle on FM. (No static at all!)

The secondary.

Is the 12V AC or DC?

If it's AC, you find a transformer that can step up voltage by approximately a factor of 10, and adjust the output as necessary (e.g. with a voltage divider).

If it's DC, then you can build an oscillator that runs on 12V DC and then put it into a transformer. Be sure to know how your oscillator's waveform is effected by the transformer.

a differential amplifier helps to increase the CMRR which in turn helps avoid unwanted signals that couple into the input to get propagated. IT also helps to increase the signal to noise ratio. furthermore it provides larger output voltage swings.

If the integrated circuit in some kind of device has 5,000 transistors on it, then

before integrated circuits were available, the same function might have been

performed by 100 individual transistors. And before transistors were available, the

same function might have been performed by 30 vacuum tubes, a fan and air system

to keep them cool, and a large power system to operate the tubes and the cooler.

In electronics DC stands for direct current. There are three types of circuits in this current. They are the closed, open, and series circuits.

1,000,000,000,000,000,000,000 = 1021 = 1 sextillion

Q: What is the difference between 'Open Loop' and 'Closed Loop'? A: When the engine is first started, and rpm is above 400 rpm, the system goes into 'Open Loop' operation. In 'Open Loop', the ECM will ignore the signal from the Oxygen (O2) sensor and calculate the air/fuel ratio based on inputs from the coolant and MAF sensors, but mostly from a pre-programmed table in the memcal. The system will stay in 'Open Loop' until the following conditions are met: 1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)

2. The coolant sensor is above a specified temperature about 40oC/104oF.

3. A specific amount of time has elapsed after starting the engine. The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.

Military Occupational Specialty. Specifies what your function in the military will be.

Voice comes in 8000 Hz frequency, so 16000 samples required each seconds.

1 sample if of 8 bits.

16000 sample if of 128000bits.

these bits is send per second.

so bandwidth required is 128kbs for single voice.

for 24 it is 24 x 128 kbps

= 3072 kbps

= 3.1 mbps

A vacuum tube is an instrument used to control the flow of electrons. The simplest form of this is called the triode and has three elements. An anode, a cathode, and a grid. The flow of electrons is always from anode to cathode the grid can influence the flow of the electrons. Like the light bulb the tube needs to be a vacuum or filled with gas to prevent the metals they are made of from catching on fire and melting.

The first person to discover that a grid could have an electric charge was Lee De Forest.

See also:

Lee De Forest

Edwin Armstrong

David Sarnoff

When you work in the field of microcontrollers, you have to deal with the hexadecimal code. Some people find it very confusing, but if you know the basics, it will be really easy for you to understand. The Intel Hex format is a standard for storing binary code in text format. It is widely used in programming microcontrollers. The Intel Hex code is used on manufacturers’ websites to provide firmware upgrades and data sheets. The Intel Hex format is also referred to as Bin HEX, u-code, or u-hex.

Typically you can call the other number and it will be disconnected but if another person answers the company may have already assigned the number to another person. The way to get around this is be direct and ask the person what their number is

FR-4 glass-reinforced epoxy. In fact, FR-4 is the grade of the fiber.

Zener diodes are widely used as voltage references and as shunt regulators to regulate the voltage across small circuits. When connected in parallel with a variable voltage source so that it is reverse biased, aZener diode conducts when the voltage reaches the diode's reverse breakdown voltage.

The only difference between a shock load and a gradually applied load is something called an impulse; defined as the integral of a force with respect to time. When a force is applied to a rigid body it changes the momentum of that body. A small force applied for a long time can produce the same momentum change as a large force applied briefly, because it is the product of the force and the time for which it is applied that is important.

S stands for slew and L stands for low frequency... and 100 is the gain of the transistor

An amplifier will amplify a signal. For example, the antenna in a radio will receive an extremely weak signal; before it can be converted to a sound, it must be amplified (made stronger), by a factor of several million.

Of course, since you can't produce energy out of nothing, an amplifier doesn't actually produce the energy for the strong version of the signal - it requires a power supply.

A race condition occurs when the output of a logic circuit is fed back into the input in such a way as to change the output, such that settling of the inputs delays the final stabilization of the outputs. It can also occur when two inputs to a circuit change at the same relative time, but the result depends on time sequence, such as in a D-FlipFlop where the clock is edge triggered.. In a full adder, for instance, propogation of carries can delay the final output, resulting in performance (speed) degradation. That is why many full adders have look-ahead carry logic. In essence, to avoid a race condition, you want to design the circuit so that propagation delay does not accumulate in series. A striking example in my memory was where an 8085 microprocessor system used WR/ to drive the databus drivers, while at the same time using WR/ to strobe the destination latches. That was a race condition, and it made the final contents of the latches indeterminant.