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10-11-2011, 10:20 AM
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#1
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Command Sergeant Major
Join Date: Mar 2011
Posts: 321
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10-11-2011, 10:20 AM
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#2
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Commander In Chief
Join Date: Oct 2010
Posts: 1,872
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46309 2007 年 11 月 02 日 12:56 Reading (loading. ..) Comments (1) Category: sincerely
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10-11-2011, 10:21 AM
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#3
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Commander In Chief
Join Date: Oct 2010
Posts: 1,872
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, designer handbags
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46483 2008 年 01 月 13 日 01:18 Reading (loading. ..) Comments (0) Category: Original Literature
1 Fixed capacitors for testing the detection
A little less than 10pF capacitance below 10pF
Fixed capacitors for the capacity is too small to be measured with a multimeter, only qualitative checks whether there is leakage, an internal short circuit or breakdown . Measurement, it can use multimeter R? 0k block, with two tables document any connection capacitance, respectively, two pins, the resistance should be infinite. If the measured resistance (pointer to the right swing) is zero, then the capacitance leakage damage or internal breakdown. B detection 10PF ~ 0.01μF capacitors have charged a fixed phenomenon, and then judge the good or bad. Multimeter use R? K block. Β value of two transistors are above 100, and the tunneling current to be small. Choice of models, such as silicon transistor formed 3DG6 composite pipe. Multimeter's red and black table pen and composite pipe, respectively, the emitter and collector c e phase. Amplification of the composite transistor, the measured capacitance of the charge-discharge process to be enlarged, so that meter rate increase put pointer, paul smith uk, and thus easy to observe. It should be noted: In the test operation, especially in the smaller capacity of the capacitance measurement, the measured capacitance pin to repeatedly swap contacts A, B two points in order to clearly see the swing meter pointer. C for more than a fixed capacitor 001μF, available multimeter R? 0k block directly test whether the process of charging the capacitor and the availability of an internal short circuit or leakage, according to the size of a pointer to the right swing to estimate the magnitude of the capacitor capacity.
2 electrolytic capacitors because of the detection
A electrolytic capacitor is much greater than the average fixed capacitor, so measurements should be the appropriate choice of different size range. Based on experience, under normal circumstances, 1 ~ 47μF capacitor between, the available R? K block measurement, mulberry bags, the capacitance can be larger than 47μF R? 00 block measurements.
B to the red multimeter pen then negative, then positive the black pen in the new to the moment, the meter pointer deflection is greater skewness to the right (for the same power block, the greater the capacity, the greater the swing), handbags online cheap, then gradually turn to the left until stopped at a location. At this point the resistance is positive electrolytic capacitor leakage resistance, this value is slightly larger than the reverse leakage resistance. Practical experience shows that the leakage resistance of electrolytic capacitors should generally be more than a few hundred kΩ, otherwise, it will not work properly. In the test, if positive, no charge reverse phenomenon, namely Biaozhen not move, then lost the capacity or the internal circuit; if the measured resistance is very small or zero, indicating that a large capacitor leakage or breakdown damage can not be used. C for the positive and negative signs of unknown electrolytic capacitors can be measured using the above method to determine leakage resistance. That is, first measured about any leakage resistance, remember its size, and then swap table T and then a resistance test. Two major resistance measurement is that a positive connection, the black test is positive then, the red pen then is negative. D multimeter power block, to the electrolytic capacitor is used, the reverse charge method, according to the size of a pointer to the right swings can estimate the electrolytic capacitor.
3 test
A variable capacitor gently rotating shaft, paul smith sale, should feel very smooth and should not feel tight and sometimes loose even when the cable wiring. The axial load before and after, up, down, left, right and other directions promotion, the shaft should not be loosening. B rotating shaft with one hand, one hand moving light touch the outer edge of the tablet group and should not feel any loose phenomenon. Shaft and moving piece of poor contact between the variable capacitor, can not continue to use. C placed in the multimeter R? 0k block, a hand table T respectively, then the two variable capacitors and fixed film fixed chip terminal, burberry handbags, the other hand will slowly rotating shaft a few back and forth, multimeter pointer location should be fixed in the infinite. In the rotating shaft of the process, if the pointer points to zero sometimes, that action films and short circuit between the stator; If you hit a certain point, the multimeter reading is not infinite but a certain resistance, indicating that dynamic variable capacitor between the plate and stator leakage phenomenon.
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10-11-2011, 10:23 AM
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#4
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Commander In Chief
Join Date: Oct 2010
Posts: 1,872
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46483 2008 年 01 月 13 日 01:20 Reading (loading. ..) Comments (0) Category: Original Literature
current
directional movement is called the charge circuit, current common I said. Both DC and AC Current. The size and direction of the current does not change over time is called the DC. Current size and direction of change over time is called the exchange. Current unit is safe (A), also commonly milliamps (mA) or microamps (uA) to do unit. 1A = 1000mA, 1mA = 1000uA. Current can be measured with the ammeter. When measured, the ammeter in series in the circuit, to select the pointer close to the full deflection of the ammeter scale. This prevents excessive current damage meter.
voltage
the river was able to flow because the water level is poor; charge was able to flow because there is potential difference. Is the voltage potential difference. Voltage causes the formation of current. In the circuit, the voltage used U said. Voltage is volt (V), also commonly used in millivolts (mV) or microvolts (uV) make units. 1V = 1000mV, 1mV = 1000uV. Voltage can be measured with a voltmeter. Measurement time, the voltmeter in parallel in the circuit, the table pointer to select the voltage close to full scale deflection. If the voltage on the circuit size estimates do not come out first with a large range, a rough measurement and then with the appropriate range. This prevents excessive damage due to voltage voltmeter.
circuit resistance on the current role and through obstacles caused by the energy consumption of the part is called resistance. Resistance of common R said. Unit of resistance is the European (Ω), also commonly used kilohms (kΩ) or megohms (MΩ) made units. 1kΩ = 1000Ω, 1MΩ = 1000000Ω. Resistance of the conductor from the conductor material, cross-sectional area and length of the decision. Resistance can be measured with a multimeter ohm file. Measuring time, deflected to choose nearly half of the meter pointer Ohm file. If the resistance in the circuit, make a hot open after resistance measurement.
Ohm's law conductor current I and the conductor is proportional to the voltage U, and the conductor resistance R is inversely proportional, that is, I = U / R. This rule is called Ohm's law. If you know the voltage, current, resistance, volume two of the three, according to Ohm's law to find the third volume, that is, I = U / R, mulberry handbags, R = U / I, U = I × R
in AC circuit, Ohm's law also set up, but the impedance of resistor R should be changed to Z, that is I = U / Z
power
to other forms of energy into electrical energy device called a power supply. Generator can convert mechanical energy to electrical energy, batteries can convert chemical energy into electrical energy. Generators, batteries and so called power. Through the transformer and rectifier, the alternating current into a device called a rectifier DC power supply. To provide an electronic device called a signal source. Transistor can be amplified before the signal sent, again amplified the signal sent to the back of the circuit to go. Transistor on the back of the circuit, can also be seen as the source. Rectifier power supply, mulberry bag, sometimes called the power source.
load
to other forms of energy can be converted into a device called a load. Motor can convert electrical energy into mechanical energy, electrical energy can converted into heat resistance, light bulbs can heat and light energy into electrical energy, the speaker can sound energy into electrical energy. Motors, resistors, light bulbs, speakers, and so is called the load. Transistor source for the front, it can also be seen as a load.
circuit current flows through the road called the circuit. The simplest circuit consists of power supply, load and wires, switches and other components. Circuit is called the channel connected everywhere. Only path, the circuit current to flow in. Disconnect the circuit is called a circuit or open circuit. Circuit is directly connected to both ends of a part, so that this part of the voltage to zero, called the short circuit.
EMF EMF to reflect the power to other forms of energy into electric energy of the ability of physical quantities. Electromotive force generated across the power supply voltage. In the circuit, the EMF used δ said. Force units and units of the same voltage is volts.
force power can voltmeter. When measured, the power receiving circuit to do with the voltmeter across the power supply voltage, the voltage value obtained can be seen as equal to the power of the force. If the power supply connected to the circuit, with a voltage meter measured the voltage across the power supply will be less than the power of the force. This is because the power supply has internal resistance. In the closed circuit, current through the resistor r are within the voltage drop through the external resistor R with foreign pressure drop. Δ is equal to the power of the EMF voltage and external voltage UR of Ur, ie, δ = Ur + UR. Strictly speaking, even if the power does not access circuit, a voltmeter measuring the voltage across the power supply, voltage meter into the external circuit, the voltage is less than the measured force. However, due to a large internal resistance of voltage meter, power supply internal resistance is small, the voltage can be ignored. Therefore, the power supply voltage meter measured the voltage across the power supply can be regarded as equal to the EMF.
batteries worn, with the voltage by measuring the voltage across the battery, and sometimes still relatively high, but can not access the circuit after the load (radios, tape recorders, etc.) normal work. This is because the larger internal resistance of the battery, even bigger than the load resistance, but still better than the small internal resistance of voltage meter. With a voltmeter across the battery voltage when the battery voltage within the share of internal resistance is not large, so the voltage meter measured the voltage is still relatively high. However, access to the circuit the battery, the battery voltage within the share of internal resistance increases, the voltage on the share of the load resistance decreases, the load can not work properly. In order to determine the old battery can not be used, when the load should be measured in a voltage across the battery. Some poor performance of the power supply, a load and no load in both cases measured the voltage difference between the larger power supply, but also because the larger the power supply caused by internal resistance.
AC cycle to complete a full change is called the cycle time required, usually T said. Period is in seconds (s), also commonly milliseconds (ms) or microseconds (us) to do unit. 1s = 1000ms, 1s = 1000000us.
AC frequency
cyclical changes in the 1s to complete the number of known frequency, commonly used f said. The unit is Hz frequency (Hz), also commonly kilohertz (kHz) or megahertz (MHz) to do unit. 1kHz = 1000Hz, 1MHz = 1000000Hz. AC frequency f is the reciprocal of period T, that is
f ; = 1 / T
capacitor conductor capacitance is a measure of physical ability to store charge. In the two mutually insulated conductors, coupled with a certain voltage, they will save some power. Save one of the conductors with a positive charge, and the other conductor save the negative charge of equal size. Coupled with the greater the voltage, the more storage capacity. Storage capacity and coupled with the voltage is directly proportional to their ratio is called the capacitance. If the voltage is expressed by U, Q, said electricity use, said capacitor with C, then
C = Q / U
capacitor unit is France (F), also commonly used in microfarads (uF) or slightly Act (pF) to do unit. 1F = 106uF, 1F = 1012pF.
capacitor capacitor tester can measure, you can also file with the multimeter ohms rough estimation. Ohmmeter red, black pen were two tables of the feet touch the capacitors, Ohm table will charge the capacitor battery, the pointer deflection, charge finished, the pointer back to zero. Exchange of red and black two tables T, and then will reverse charging capacitor discharge. Capacitance greater the greater the deflection of the pointer. Compare the measured capacitance and the capacitance of the deflection of known cases, a rough estimate can be measured capacitance value. Electronic circuits in general, in addition to other needs tuning circuit capacitor capacity of more than accurate, the most used blocking, bypass capacitors, filter capacitors, capacitors do not need the capacity and accurate. Thus, a rough estimate capacitance values Ohm file is meaningful. But ordinary multimeter ohms file can only estimate the value larger capacitance value of capacitance necessary to use smaller value resistors in the transistor large files multimeter ohms to estimate, slightly less than the dozens of law The capacitance tester had measured using a capacitance.
anti
content is through ac capacitor, but the capacitance of the AC still have them back. Impediment to the AC capacitor is called capacitance. Large capacity, easy to pass the AC capacitor, indicating large capacity capacitor hinder small; high frequency alternating current, AC is also easy to pass capacitor, indicating that high frequency capacitance impediment is also small. Experimental results show that capacitance and the capacitance is inversely proportional, and the frequency is inversely proportional. If the capacitance with XC, said capacitor with a C, designer handbags cheap, said the frequency indicated by f, then
; XC = 1 / (2πfC)
capacitance of the unit is the Euro. Know the frequency f and the capacitance of the AC C, can be used for type to calculate the capacitance.
inductance inductance electromagnetic induction coil is a measure of physical ability. Pass into the current to a coil, the magnetic field is generated around the coil, the magnetic flux through the coil there. Coil power leads to greater, the stronger the magnetic field, the greater the magnetic flux through the coil. Experiments show that the magnetic flux through the coil and access to the current is directly proportional to the ratio of their inductance is called, also known as inductance. If the magnetic flux through the coil indicated by φ, the current use of I said that the inductor with L, then
; L = φ / I
unit of inductance is Henry (H), also commonly used millihenry (mH) or micro-Henry (uH) to do unit. 1H = 1000mH, 1H = 1000000uH.
anti
sense can also ac coil, designer handbags online, the coil inductance on the AC but hinder the role of the obstacles is called reactance. Inductor volume, difficult to pass the AC coil, indicating that large inductors, inductance major impediment; high frequency alternating current, alternating current through the coil is difficult to illustrate high frequency inductor impediment is also large. Experiments show that the inductance and inductance is proportional, and proportional to frequency. If the inductive reactance XL with said inductor with L said that the frequency with f, then
; XL = 2πfL
inductance of the unit is in Europe. Know the frequency f and the AC coil inductance L, can be used for type to calculate the inductance.
Resistance
with resistance, inductance and capacitance circuit, the obstacles on the role played by alternating current is called impedance. Common impedance Z said. Resistance and the resistance, inductance and capacitance composed of three, but not a simple sum of the three. If the three are connected in series, they know the frequency of alternating current f, resistor R, handbags online cheap, inductor L and capacitor C, then the series circuit impedance
;
impedance unit is Europe.
for a specific circuit, the impedance is not constant, but varies with frequency. In resistors, inductors and capacitors in series circuit, the impedance of the circuit resistivity generally large. Impedance is reduced to minimum. Inductor and capacitor in parallel circuit, paul smith uk, the resonant resistance increases when the maximum, this and the series circuit the opposite.
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10-11-2011, 10:24 AM
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#5
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Commander In Chief
Join Date: Oct 2010
Posts: 1,872
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(Tel wrong) looked to turn go, mulberry bags! Tian Tian, for his popular space Oh! Hee hee, designer handbags cheap! 【Not going to turn to Do not look】 - Qzone log
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Reprinted from alumni of the user at 10:04 on November 11, 2010 Reading (loading. ..) Comments (0) Category: Personal Diary
rings, designer handbags, the little girl picked up the phone handset ... ...
man: uncle in the upstairs room. Every time you come to work after Chen Shushu ah. > The little girl said excitedly: > The little girl did so, and soon heard a scream, designer handbags online, followed by a little girl I talk to ... ...
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man:
Man:
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10-11-2011, 10:25 AM
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#6
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Commander In Chief
Join Date: Oct 2010
Posts: 1,872
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46483 2008 年 01 月 13 日 01:24 Reading (loading. ..) Comments (0) Category: Personal Diary
First, the resistance of resistors in the circuit using
Resistance in the circuit for the shunt main role, the current limit, voltage, bias and so on.
1, parameter identification: resistance in ohms (Ω), rate units are: kilohms (KΩ), megohm (MΩ) and so on. Conversion is: 1 Mohm = 1000 = 1000000 EU
kilohms resistance Tagging There are 3 parameters, namely, direct standard method, method and digital color standard method.
a, the number of such standard method is mainly used for small size of the circuit chip, such as: 472, said 47 × 100Ω (ie 4.7K); 104 indicates 100K
b, color ring labeling method most used are for example as follows: four-color colored ring ring resistance resistor (precision resistance)
2, resistance ratio between location and color as follows: color valid number ratio tolerance (%)
silver / x0.01 ± 10
gold / x0.1 ± 5
Black 0 +0 /
Brown 1 x10 ± 1
Red 2 x100 ± 2
Orange 3 x1000 /
Yellow 4 x10000 /
5 x100000 ± 0.5
green blue purple 6 x1000000 ± 0.2
7 x10000000 ± 0.1
Gray 8 x100000000 /
White 9 x1000000000 /
Second, the capacitor
1, handbags online, capacitance in the circuit was used in the Capacitance is close to the two metal films, separated by insulating material which consists of separated components. The properties of capacitors is blocking flow of exchanges. The size of capacitance that can store energy that is the size of capacitor hinder the exchange of signals is called capacitive reactance, it flows and exchange
signal frequency and volume. Capacitive reactance XC = 1/2πf c (f the frequency of AC signal, said, C said capacitance) capacitor commonly used types of phones are electrolytic capacitors, ceramic capacitors, chip capacitors, monolithic capacitors, tantalum capacitors and polyester capacitors .
2, identification: Identification of capacitance and resistance identification method is basically the same, sub-standard method until the color standard method and several standard method 3. The basic unit of capacitance with Farah (F), said other units are: mm method (mF), microfarad (uF), mobility method (nF), skin method (pF). Where: 1 = 103 cents Law Farah micro-method = 109 = 106 = 1012 picofarads satisfied law
capacity value of capacitance capacitor capacity directly marked, such as 10 uF/16V
small capacity capacitor capacity value of the capacitor to a letter or number that
letter notation: 1m = 1000 uF 1P2 = 1.2PF 1n = 1000PF
numerical representation: the capacity for general use, said the size of three digits, said first two digits , the third digit is the magnification.
such as: 102, said 10 × 102PF = 1000PF 224, said 22 × 104PF = 0.22 uF
3, Table
capacitance symbol FGJKLM
error tolerance ± 1% ± 2% ± 5% ± 10 % ± 15% ± 20%. such as: a ceramic capacitor that capacity for the 104J 0. 1 uF, error is ± 5%.
Third, the crystal diode
crystal diode circuits used in
1, role: The main characteristics of the diode is a one-way conductivity, which is under the effect of the forward voltage, burberry bags, resistance is very small; in reverse voltage resistance under maximum or infinite. Because the diode has the characteristics of cordless telephones often use it in the rectifier, isolation, voltage, polarity protection, coding control, frequency modulation and suppression and other circuits.
telephone in accordance with the role of the crystal diode can be divided into: rectifier diode (eg 1N4004), isolation diode (eg 1N4148), Schottky diode (such as BAT85), light emitting diodes, voltage regulator diodes.
2, identification: Identification of the diode is very simple, low-power diode N pole (negative), most of the diode appearance marked by a color ring out, and some special symbols diode diode is also used to represent the P pole (positive) or N pole (negative), mulberry bag, there is also symbol for the Positive and negative light-emitting diodes from pin
not know the length of long leg is positive, the short leg is negative.
3, test Note: use the digital multimeter to test diodes, the red pen then the positive terminal of the diode, the black pen then the negative terminal of the diode, when the measured resistance is the resistance of the diode is forward, which Analog Multimeter table with the pen connection just the opposite.
4, used the 1N4000 series diode voltage is as follows:
Model 1N4001 1N4002 1N4003 1N4004 1N4005 1N4006 1N4007
voltage (V) 50 100 200 400 600 800 1000
Current (A) are 1
IV
regulator diode zener diodes used in the circuit 1, paul smith wallet, the voltage regulator diode principle: that the breakdown voltage characteristics of diode, its voltage across essentially unchanged. Thus, when access to the circuit after the regulator, if the supply voltage fluctuation, or other points in the circuit causes power
pressure changes, the voltage across the load will be basically unchanged.
2, fault characteristics: Zener diode fault mainly in the open, short and unstable voltage values. 3 failures in this, the first of a failure to show increased supply voltage; failure after 2 to low performance of the supply voltage to zero volts or output instability.
common voltage regulator diode model and values as follows: Type 1N4728 1N4729 1N4730 1N4732 1N4733 1N4734 1N4735 1N4744 1N4750 1N4751 1N4761
voltage value 3.3V 3.6V 3.9V 4.7V 5.1V ; 5.6V 6.2V 15V 27V 30V 75V
V.
inductor used in the circuit inductance inductor that number is 6. Inductance coil is insulated wire around the insulation of the skeleton made of a certain number of laps. DC through the coil, DC resistance is the resistance wire itself, a small pressure drop; when the AC signal through the coil, the coil inductance force will be generated, self force in the direction opposite the direction of the applied voltage and hinder the exchange of passed, so the characteristics of the inductor DC resistance is through communication, the higher the frequency, the greater the coil impedance. Inductor and capacitor in the circuit can be composed of oscillation
circuit.
inductors generally have direct standard method and color standard method, standard method and the resistance of a similar color. Such as: brown, black, gold, gold that 1uH (error 5%) of the inductor. The basic unit of inductance
: Henry (H) conversion units: 1H = 103mH = 106uH.
VI
varactor varactor diode in accordance with ordinary internal Varactor is mainly used in cordless phone base in the mobile phone or high-frequency modulation circuit, low frequency to high frequency modulated signal, and launch out. In the working state, the varactor modulation voltage is generally added to the anode, so that the internal junction varactor capacitance changes with the modulation voltage changes.
varactor failure, mainly for the leakage or performance variation:
(1) leakage phenomenon occurs when the frequency modulation circuit will not work or modulation performance deteriorated.
(2) modulation in poor performance, the high frequency modulation circuit of job insecurity, the modulated high frequency signal is sent to each other after the other receivers distortion. One of the above circumstances, it should be replaced with the type of varactor diodes.
seven
transistor transistor commonly used in the circuit
1, features: transistor (the transistor) is the interior includes two PN junction, and a special device with amplification. NPN and PNP type is sub-type of two types, both types of transistor characteristics from the work on each other to make up the so-called OTL circuit is on the tube by the PNP type and NPN type paired. Telephone in the PNP-type transistors are commonly used: A92, 9015 and other models; NPN-type transistor are: A42, 9014,9018,9013,9012 models.
2, transistor amplifier is mainly used for amplification played in three common circuit connection. For comparison, three connection transistor circuit with the characteristics listed in the table below, for your reference. Name of the common emitter circuit common collector circuit (emitter)
common base input impedance of the circuit (a few hundred ohms to several thousand Euro) Large (more than tens of thousands of Euro) small (a few European ~ dozens of Europe)
output impedance (~ tens of thousands of thousands of Europe Europe) small (a few ohms to tens of Europe) large (tens of thousands of ohms to hundreds of thousands of Euro)
voltage magnification size (less than 1 and close to 1) a large current amplification factor
large (tens of) large (dozens) of small (less than 1 and close to 1)
power magnification of large (about 30 40 dB) small (about 10 dB) in (about 15 ~ 20 dB)
difference between a good high frequency characteristics of multi-stage amplifier applications
intermediate frequency amplification input, paul smith uk, output, or for impedance matching high frequency or broadband circuit and constant current source circuit
eight field-effect transistor amplifier
1, field-effect transistors with high input impedance and low noise, etc., which are also widely used in various electronic devices. In particular, effective use of electronic equipment to do the whole tube input stage, can be difficult to achieve the general performance of the transistor.
2, junction field effect transistor and insulated gate is divided into two major categories, the control principle is the same.
3, FET transistors compared with
(1) field effect transistor is the voltage control device, while the transistor is a current control device. The only source to take less from the current case, the FET should be used; in the signal voltage is low, but also allows more current from the source under the conditions of access should be used in transistors.
(2) FET is the use of majority carrier conduction, so called unipolar device, the transistor is that a majority carrier, also used minority carrier conduction. Known as bipolar devices.
(3) some of the FET source and drain can be used interchangeably, the gate voltage can be positive or negative, flexibility, designer handbags cheap, better than transistors.
(4) FET in a very small current and low voltage conditions, work, and its manufacturing process can be easily integrated into many a piece of silicon FET, so FET large-scale IC has been widely used.
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10-11-2011, 10:28 AM
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#7
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Commander In Chief
Join Date: Oct 2010
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46483 2008 年 01 月 13 日 01:23 Reading (loading. ..) Comments (0) Category: Personal Diary
Inductors coil wire is looped around a circle by insulating pipe, wire insulation each other, and insulated pipes can be hollow, also contain iron core or magnetic core, referred to as inductance. With L said that the unit has Henry (H), mg Henry (mH), micro-Henry (uH), 1H = 10 ^ 3mH = 10 ^ 6uH.
one inductor inductor in the form according to the classification of
Category: Fixed inductors, variable inductors.
magnet according to the nature of Category: Air Core Coil, Ferrite coil, designer handbags cheap, iron core coil, copper coil.
classified by the nature of work: the antenna coil, the oscillation coil, choke coil, notch coils, handbags online, deflection coils.
by winding of structure: single-coil, multi-layer coil, honeycomb coil.
Second, the main characteristic parameters of the inductor coil
1, inductance L
coil inductance L that the inherent characteristics, and current size. In addition to a special induction coil (color code inductance), the inductance of the coil is generally not specifically marked, while the name of a particular label.
2, the inductor coil inductance XL
hinder the size of the AC current, said inductive reactance XL, unit is the ohm. It is with the inductance L and the relation between the AC frequency f XL = 2πfL
3, quality factor Q
said coil quality factor Q is the quality of a physical quantity, Q for the inductive reactance XL the ratio of its equivalent resistance, that is: Q = XL / R. The higher the Q value of the coil, mulberry bags, the smaller the loop loss. Q value of the coil wire DC resistance, the skeleton of the dielectric loss, caused by shield or core loss, high frequency skin effect and other factors. Q value of the coil is usually tens to hundreds.
4,
distributed capacitance between coil turns and turns, the coil and the shield, the coil and the capacitance between the bottom plate is known as distributed capacitance. The presence of distributed capacitance coil Q value decreases, the stability of variation, and thus the distribution of capacitance of the coil as small as possible.
Three commonly used coil
1, single-coil
single-layer insulated wire coil is wound around to endure around the skeleton in the paper or bakelite. Such as the transistor radio wave antenna coil.
2, honeycomb coil
If the wound coil, paul smith uk, the plane is not parallel to the surface with the rotation, but intersect at an angle, such as honeycomb coil coil . And its rotation a week, the number of wire bent back and forth, often referred to as discount points. Honeycomb around the method has the advantage of small size, distribution of capacitance and large inductance. Honeycomb honeycomb coil winding machines are used to around the system, the more discount points, distributed capacitance smaller
3, ferrite core coil and iron core coils
the inductance on the size and whether the core. Inserted in the hollow ferrite core coil, the coil increases the inductance and improve the quality factor.
4, copper coil copper coil
more in the VHF range of applications, the use of rotating the position of copper in the coil to change the inductance, mulberry handbags, this adjustment is convenient, durable.
5,
color code color code inductor inductor inductor is a fixed amount of inductor, the inductance method of the same sign as the color ring resistance to marking.
6, choke ring (choke)
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7, deflection coil
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