Lithium-ion Battery

Lithium-ion Battery is superior in performance..

Does not contain any mercury, cadmium and toxic element, is truly environmentally friendly batteries.

In addition to the dual over-current protection of overheating, but also built-in smart IC protection circuit.
With the affordability of high-power, fully meet the camera / digital camera load power requirements of all relevant, showing the excellent characteristics of constant voltage source.
Charging process can be completed quickly, completely without memory effect.
Even if the high-power charge-discharge, high frequency used, and their life cycle than nickel-metal hydride battery is still more than 1 times.
Charge retention capability, the monthly charge retention rate of more than 92%.
With the best internal consistency, to ensure that each "charge-discharge" process consistency, to ensure that the overall battery life of up to

The working principle of lithium-ion battery 

The working principle of lithium-ion battery is that its charging and discharging. When charging the battery, the battery on the positive ion generation, generation of lithium-ion movement through the electrolyte to the cathode. As the carbon cathode layered structure, it has many pores, to reach the negative electrode of lithium-ion embedded in porous carbon layer, the more embedded lithium-ion, the higher the charge capacity. When the battery discharge, embedded in the negative ion of carbon layer prolapse, and movement back to positive. Back to the cathode of lithium-ion more discharge capacity is higher. Commonly referred to as battery capacity refers to the discharge capacity. Lithium-ion battery charge and discharge process is positive → negative → positive from the movement. Battery terms

Battery: refers to the reaction between the positive and negative chemical energy into electrical energy.
● a battery: that can not be charged, the battery can only discharge, but the battery capacity is generally greater than the same size rechargeable batteries, such as manganese, alkaline batteries, lithium button batteries, lithium batteries
● secondary batteries: Refers to rechargeable battery recycling, such as lead-acid, nickel cadmium, nickel hydrogen, lithium ion, lithium polymer, fuel, zinc, aluminum, magnesium air battery.

Electronic Amplification

Amplifier,  in electronics, device that responds to a small input signal (voltage, current, or power) and delivers a larger output signal that contains the essential waveform features of the input signal. Amplifiers of various types are widely used in such electronic equipment as radio and television receivers, high-fidelity audio equipment, and computers. Amplifying action can be provided by electromechanical devices (e.g., transformers and generators) and vacuum tubes, but most electronic systems now employ solid-state microcircuits as amplifiers. Such an integrated circuit consists of many thousands of transistors and related devices on a single tiny silicon chip.

A single amplifier is usually insufficient to raise the output to the desired level. In such cases the output of the first amplifier is fed into a second, whose output is fed to a third, and so on, until the output level is satisfactory. The result is cascade, or multistage amplification. Long-distance telephone, radio, television, electronic control and measuring instruments, radar, and countless other devices all depend on this basic process of amplification. The overall amplification of a multistage amplifier is the product of the gains of the individual stages.

There are various schemes for the coupling of cascading electronic amplifiers, depending upon the nature of the signal involved in the amplification process. Solid-state microcircuits have generally proved more advantageous than vacuum-tube circuits for the direct coupling of successive amplifier stages. Transformers can be used for coupling, but they are bulky and expensive.

An electronic amplifier can be designed to produce a magnified output signal identical in every respect to the input signal. This is linear operation. If the output is altered in shape after passing through the amplifier, amplitude distortion exists. If the amplifier does not amplify equally at all frequencies, the result is called frequency distortion, or discrimination (as in emphasizing bass or treble sounds in music recordings).

When the power required from the output of the amplifier is so large as to preclude the use of electronic devices, dynamoelectric and magnetic amplifiers find wide application.

8 MILLION GAIN!

This circuit is so sensitive it will detect "mains hum." Simply move it across any wall and it will detect where
the mains cable is located. It has a gain of about 200 x 200 x 200 = 8,000,000 and will also detect static electricity and the presence of your hand without any direct contact. You will be amazed what it detects! There is static electricity EVERYWHERE! The input of this circuit is classified as very high impedance.

SIMPLEST CIRCUIT

This is the simplest circuit you can get. Any NPN transistor can be used.

Connect the LED, 220 ohm resistor and transistor as shown in the photo.
Touch the top point with two fingers of one hand and the lower point with fingers of the other hand and squeeze.
The LED will turn on brighter when you squeeze harder.
Your body has resistance and when a voltage is present, current will flow though your body (fingers). The transistor is amplifying the current through your fingers about 200 times and this is enough to illuminate the LED.

TRANSISTORS

Introduction
In 1956 the Nobel prize for physics was awarded to Shockley, Bardeen and Brattain for the invention of the transistor. The transistor has enabled the modern telecommunications revolution.


The Transistor
The transistor is an electronic device that transforms small electrical currents (and voltages) into larger copies of the original - it is what is called an amplifier and is said to have 'gain' (magnification). The transistor has three wire connections called; the emitter (E), the base (B) and the collector (C). By wiring the device up with other simple components an amplifier can easily be constructed. A typical transistor has a gain of about 100 times.
The physical theory describing the transistor involves understanding the movement of electrons (and the absence of electrons - holes) in P and / or N doped semiconductor materials. What follows here is not a detailed account of the theory but a simple set of experiments that demonstrates the transistor working.

How it works
A diode is a two wire electronic component that only conducts electricity when connected the 'correct way round' i.e. with the potentials applied correctly. It is composed of a P and N semiconductor junction. The transistor is a three wire component composed of a sandwich of either PNP or NPN junctions.

Electrically it is as if the transistor is composed of two diodes wired back to back. The common middle region (the base - B) of the transistor is much thinner than the other two regions.
 Because the diodes are opposed to each other no current would normally flow when a voltage is applied between the emitter and the collector - EC (although there may be a tiny leakage current).
If a voltage is applied across BE (B positive and E negative for an NPN transistor) this junction will be forward biased so a current will flow in this circuit. However, because the base region is very thin (and also because when wired up correctly the collector is at a high potential and so attracts electrons) as much as 99% of this current will actually flow right across the base region to reach the collector (C). So we have actually made the EC circuit of the transistor conduct by applying a current into B (set up by a small voltage across BE).
Now the current flowing from the emitter must be equal to the sum of i) the 99% arriving at the
collector and ii) the 1% that is left flowing through the base. So the base current is small, only 1%
or so. But as we have seen the collector current can not exist without the little base current and so
it is effectively controlling the collector current. This collector current is a larger copy of the base
signal and so we find the transistor produces a current gain! Current gains of 100-200 are typical
for a transistor. Usually the EC part of the circuit is used as the output and the base is used as the
input of the amplifier.
The EB circuit is low voltage and low current while the EC is at a much higher potential and higher
current. As power = voltage x current we must therefore have a higher power in EC and so a
power-gain is possible with such a simple circuit. Of course the transistor does not amplify this
small base signal by 'magic', the extra power is derived from the supply driving the transistor
circuit. The transistor needs a battery, or other supply, to work its 'magic'.

DIODE

A diode is a specialized electronic component with two electrodes called the anode and the cathode. Most diodes are made with semiconductor materials such as silicon, germanium, or selenium. Some diodes are comprised of metal electrodes in a chamber evacuated or filled with a pure elemental gas at low pressure. Diodes can be used as rectifiers, signal limiters, voltage regulators, switches, signal modulators, signal mixers, signal demodulators, and oscillators.

The fundamental property of a diode is its tendency to conduct electric current in only one direction. When the cathode is negatively charged relative to the anode at a voltage greater than a certain minimum called forward breakover, then current flows through the diode. If the cathode is positive with respect to the anode, is at the same voltage as the anode, or is negative by an amount less than the forward breakover voltage, then the diode does not conduct current. This is a simplistic view, but is true for diodes operating as rectifiers, switches, and limiters. The forward breakover voltage is approximately six tenths of a volt (0.6 V) for silicon devices, 0.3 V for germanium devices, and 1 V for selenium devices.

The above general rule notwithstanding, if the cathode voltage is positive relative to the anode voltage by a great enough amount, the diode will conduct current. The voltage required to produce this phenomenon, known as the avalanche voltage, varies greatly depending on the nature of the semiconductor material from which the device is fabricated. The avalanche voltage can range from a few volts up to several hundred volts.

When an analog signal passes through a diode operating at or near its forward breakover point, the signal waveform is distorted. This nonlinearity allows for modulation, demodulation, and signal mixing. In addition, signals are generated at harmonics, or integral multiples of the input frequency. Some diodes also have a characteristic that is imprecisely termed negative resistance. Diodes of this type, with the application of a voltage at the correct level and the polarity, generate analog signals at microwave radio frequencies.

Semiconductor diodes can be designed to produce direct current (DC) when visible light, infrared transmission (IR), or ultraviolet (UV) energy strikes them. These diodes are known as photovoltaic cells and are the basis for solar electric energy systems and photosensors. Yet another form of diode, commonly used in electronic and computer equipment, emits visible light or IR energy when current passes through it. Such a device is the familiar light-emitting diode (LED).

SEMICONDUCTORS

A semiconductor has electrical conductivity intermediate to that of a conductor and an insulator. Semiconductors differ from metals in their characteristic property of decreasing electrical resistivity with increasing temperature. Semiconductor materials are useful because their behavior can be manipulated by the addition of impurities, known as doping. The comprehensive theory of semiconductors relies on the principles of quantum physics to explain the motions of electrons through a lattice of atoms.

Current conduction in a semiconductor occurs via mobile or "free" electrons and holes, collectively known as charge carriers. Doping a semiconductor with a small amount of impurity atoms greatly increases the number of charge carriers within it. When a doped semiconductor contains excess holes it is called "p-type", and when it contains excess free electrons it is known as "n-type". The semiconductor material used in devices is doped under highly controlled conditions to precisely control the location and concentration of p- and n-type dopants.

Semiconductors are the foundation of modern electronics, including radio, computers, and telephones. Semiconductor-based electronic components include transistors, solar cells, many kinds of diodes including the light-emitting diode (LED), the silicon controlled rectifier, photo-diodes, and digital and analog integrated circuits. Increasing understanding of semiconductor materials and fabrication processes has made possible continuing increases in the complexity and speed of semiconductor devices, an effect known as Moore's Law.

INDUCTORS, What do they do?

             The electronic component known as the inductor is best described as electrical momentum. In our water pipe analogy the inductor would be equivalent to a very long hose that is wrapped around itself many times . If the hose is very long it will contain many gallons of water. When pressure is applied to one end of the hose, the thousands of gallons of water would not start to move instantly. It would take time to get the water moving due to inertia (a body at rest wants to stay at rest). After a while the water would start to move and pick up speed. The speed would increase until the friction of the hose applied to the amount of pressure being applied to the water. If you try to instantly stop the water from moving by holding the plunger, the momentum (a body in motion wants to stay in motion) of the water would cause a large negative pressure (Suction) that would pull the plunger from your hands.
           Since Inductors are made by coiling a wire, they are often called Coils. In practice the names Inductor and Coil are used interchangeably. From the above analogy, it is obvious that a coiled hose will pass Direct Current (DC), since the water flow increases to equal the resistance in the coiled hose after an
elapsed period of time. If the pressure on the plunger is alternated (pushed, then pulled) fast enough, the water in the coil will never start moving and the Alternating Current (AC) will be blocked. The nature of a Coil in electronics follows the same principles as the coiled hose analogy. A coil of wire will pass DC and block AC. Recall that the nature of a Capacitor blocked DC and passed AC, the exact opposite of a coil. Because of this, the Capacitor and Inductor are often called Dual Components.
         The Inductor prevents current from making any sudden changes by producing large opposing voltages. Magnetic coupling can be used to transform voltages and currents, but power must remain the same. Coils and transformers can be used to select frequencies.

INDUCTANCE SYMBOLS AND MARKINGS
       Most inductors are custom made to meet the requirements of the purchaser. They are marked to match the specification of the buyer and therefore carry no standard markings. The schematic symbols for coils and transformers are shown in fig . These symbols are the most commonly used to represent fixed coils, variable coils, and transformers.

CAPACITORS

A capacitor stores electrical energy when charged by a DC source. It can pass alternating current (AC), but blocks direct current (DC) except for a very short charging current, called transient current.

          Capacitors are components that can store electrical pressure (Voltage) for long periods of time. When a capacitor has a difference in voltage (Electrical Pressure) between its two leads it is said to be charged. A capacitor is charged by forcing a one way (DC) current to flow through it for a short period of time. It can be discharged by letting an opposite direction current flow out of the capacitor.

Introduction

There are many different types of capacitors in use in electronics. Although all perform the same basic function, factors such as the type of construction, tolerance, working voltage and temperature coefficients need to be taken into account when selecting a capacitor. This tutorial is a practical guide to selecting the right capacitor for any circuit. 

Value

Capacitors are available in sizes from 1pF (1 x10-12 F) to 100,000mF. Depending on the type of capacitor, it may not be available in every value.

Working Voltage

The general rule is always use a capacitor with a higher working voltage than the circuit it is used in. This is of particular importance in power supply circuits with high value electrolytic capacitors. The working voltage should always exceed the peak working voltage of the circuit by a minimum of 20%. 

Polarisation

Capacitors that are polarised, have marked positive and negative terminals. They must never be connected the wrong way around or used in a circuit where the voltage may reverse polarity. Some electrolytics may explode if connected incorrectly.

Tolerance

Some circuits e.g. timing or oscillators may require a high precision capacitor. If the capacitor used does not have the same tolerance as stated in the parts list, then the circuit may not give the desired results or may not work.

Temperature Coefficient

This is the variation of capacitance with temperature. Sometimes called Tempco and may be expressed as a percentage or as a variation in parts per million per degree Celsius. Capacitors may have positive or negative temperature coefficients; i.e. their value increases or decreases with temperature or NPO (Negative Positive Offset). NPO capacitors are often used in radio and tuned circuits.

Leakage Current

In some capacitors, a leakage current flows through the dielectric and it may not hold its charge for long enough. Low leakage capacitors are available such as Tantalum Bead, and find use in applications like timing circuits.

 Polyester

Polyester capacitors are available from 1nF to 15uF. Sometimes packaged in colour bands matching the resistor colour code (above) and sometimes plain (below). Working voltages between 50V and 1500V and are available in 5%, 10%, 15% tolerance. Often used in decoupling circuits.

Polycarbonate

These capacitors are available from 100pF to 10uF, working voltages up to 400V and tolerance 5% or 10%. They have a temperature coefficient of about 100 ppm / °C. Often used in filtering and timing circuits.

Ceramic Disc

Ceramic disc are available from 1pF to 220nF, working voltages up to 100V and available in wide tolerance ranges. They are used for many purposes including decoupling circuits and have high capacitance for their small size.

 Electrolytic

Electrolytics are available from 1uF to 47000uF, working voltages up to 600V and available in wide tolerance ranges. They are used extensively in power supplies, audio amplifiers and decoupling work. Care must be taken to connect with the correct polarity, otherwise gas can form and case explode.

Variable and Trimmer

Variable capacitors are used extensively in radio circuits, RF oscillators and transmitters. Often available as single gang or multi gang and are available from 25p to 1000pF. The trimmer capacitor is the smaller brother and once adjusted is left fixed. Trimmers are available from 5p to 100pF.

RESISTORS, Types

There are many different types of resistors used in electronics. Each type is made from different materials. Resistors are also made to handle different amounts of electrical power. Some resistors may change their value when voltages are placed across them. These are called voltage dependent resistors or nonlinear resistors. Most resistors are designed to change their value when the temperature of the resistor changes. Some resistors are also made with a control attached that allows the user to mechanically change the resistance. These are called variable resistors or potentiometers.

The value of wirewound resistors remain fairly flat with increasing temperature, but change greatly with frequency. It is also difficult to precisely control the value of the resistor during construction so they must be measured and sorted after they are built.
1.THE CARBON COMPOSITION RESISTOR
      By grinding carbon into a fine powder and mixing it with resin, a material can be made with different resistive values. Conductive leads are placed on each end of a cylinder of this material and the unit is then heated or cured in an oven. The body of the resistor is then painted with an insulating paint to prevent it from shorting if touched by another component. The finished resistors are then measured and sorted by value . If these resistors are overloaded by a circuit, their resistance will permanently decrease. It is important that the power rating of the carbon composition resistor is not exceeded.

Resistor

2.THE WIREWOUND RESISTOR

     The first commercial resistors made were formed by wrapping a resistive wire around a non-conducting rod . The rod was usually made of some form of ceramic that had the desired heat properties since the wires could become quite hot during use. End caps with leads attached were then placed over the ends of the rod making contact to the resistive wire, usually a nickel chromium alloy.

Resistor

3.CARBON FILM RESISTORS

      Carbon film resistors are made by depositing a very thin layer of carbon on a ceramic rod. The resistor is then protected by a flameproof jacket since this type of resistor will burn if overloaded sufficiently. Carbon film resistors produce less electrical noise than carbon composition and their values are constant at high frequencies. You can substitute a carbon film resistor for most carbon composition resistors if the power ratings are carefully observed. The construction of carbon film resistors require temperatures in excess of 

1,000OC.

Resistor

4.THE VARIABLE RESISTOR

      When a resistor is constructed so its value can be adjusted, it is called a variable resistor. Figure 6 shows the basic elements present in all variable resistors. First a resistive material is deposited on a non-conducting base. Next, stationary contacts are connected to each end of the resistive material. Finally, a moving contact or wiper is constructed to move along the resistive material and tap off the desired resistance. There are many methods for constructing variable resistors, but they all contain these three basic principles.

Resistor

5.METAL OXIDE RESISTORS

           Metal oxide resistors are also constructed in a similar manner as the carbon film resistor with the exception that the film is made of tin chloride at temperatures as high as 5,000OC. Metal oxide resistors are covered with epoxy or some similar plastic coating. These resistors are more costly than other types and therefore are only used when circuit constraints make them necessary.

6.METAL FILM RESISTORS

          Metal film resistors are also made by depositing a film of metal (usually nickel alloy) onto a ceramic rod. These resistors are very stable with temperature and frequency, but cost more than the carbon film or carbon composition types. In some instances, these resistors are cased in a ceramic tube instead of the usual plastic or epoxy coating