Tuesday, June 29, 2010

Naruto Fakku Doujinshi

Aufbau und Funktionsweise


Ein MOSFET ist ein aktives Bauelement mit mindestens drei Anschlüssen (Elektroden): G (gate, dt. Steuerelektrode), D (drain, dt. Abfluss), S (source, dt. Quelle). Bei einigen Designs, an additional port B (bulk, substrate) to the outside. In most cases, the bulk is internally connected to the source.
Like other field-effect transistors affects the MOSFET as a voltage-controlled resistor, that is, the gate-source voltage UGS, the resistance between drain and source RDS and thus the current IDS (simplified ID) can be changed by several orders of magnitude by RDS . The key to understanding this change in resistance of a MOS structure is the origin (enrichment types) and destruction (depletion type) of a conducting channel under the gate (see below).
basic types [edit]
Like the bipolar transistor is also the MOSFET in the two basic variants of p-type (also p-type or PMOS) and n-type (also n-type or NMOS) each. If, for example in digital integrated circuits, using both types together, it is called CMOS (English: Complementary MOS). In addition, there are two versions of two forms that differ in their internal structure and the electrical characteristics:
depletion (English: depletion) - also conducting themselves, normal-to normal-conducting
enhancement type (English: enhancement) - also self-locking, normally-off, blocking normal
In practice, used by a large majority enrichment types.
General structure and physical function [Edit]
An example is given of the normally off n-channel MOSFET.
serves as the base material is a weakly p-doped silicon (substrate). In this substrate, two heavily n-doped regions admitted that generate the source and drain connection. Between the two areas is still the substrate, resulting in a npn structure which allows for the time being, no current flow (see npn transistor: Without the transistor base current blocked). Just above the remaining space is now a very thin, durable insulating (dielectric, usually silicon dioxide) is applied. The dielectric separating the overlying gate electrode from the silicon (or more precisely from the canal area). As gate material was bi

s used mid-1980 aluminum, which for n + and p + doped (degenerate) polysilicon (polycrystalline abbreviation Silicon has been replaced).
form by this structure gate terminal, bulk terminal dielectric and a capacitor that is charged when a voltage between the gate and bulk. By the electric field migrate in the substrate minority carriers (electrons in p-silicon) to the boundary layer and recombine with the majority carriers (defect electrons in p-silicon). This affects how a displacement of the majority carriers and is "poverty" is named. At a certain voltage Uth (engl. threshold voltage, threshold voltage) is the displacement of the majority charge carriers such that they are no longer available for recombination stand. There is an accumulation of minority carriers, thereby actually p-doped substrate n close to the insulating-conducting. This condition is called strong "inversion". The resulting thin n-type channel now connects the two n regions the source and drain, which charge carriers (almost) to flow freely from source to drain can.
operation areas of an n-channel MOSFET
In principle, source and drain initially equivalent, usually the structure is not symmetrical, a better behavior to achieve. Moreover, in most types, bulk internally connected to Source as a potential difference between source and bulk properties of the transistor (in particular the threshold voltage) negatively affected (body effect). On the basic function, the connection control. However, this will create an additional diode between source and drain, which is parallel to the actual transistor (with the bulk p-doped substrate and drain connected to the n region form the pn junction). This so-called body diode is shown as an arrow in the symbol for a MOSFET and shows the n-channel MOSFET of the bulk terminal to the channel. If the application is the body diode is usually biased in the reverse direction, with some switching applications However, it can be used to prevent reverse operation. You can run the full drain current of MOSFETs on but relatively slowly, so that used for quick switch external diodes See well. Field-effect transistor
variations in the structure [change]
addition to the conventional MOSFET variants exist several special variants with altered structure. The goal is a better circuit behavior, which is associated with some cases significantly increased manufacturing costs. Examples are the VMOS FET or the FinFET, the latter has the advantage of an increased channel region; because of the channel areas often referred to as dual (tetrode) or tri-gate. [2] [3] They are used for example in RF circuits (RF amplifiers, mixers multiplicative).

;

Luis Fernando Cantor B.
Electronica de Estados Solidos
Seccion 2

Welcoming A New Employe

Building Mixers


A much more flexible option is to use a mixer, a device which allows the outputs of multiple players to be summed together. With this technique, no input switching is required and the advanced crossfading features of the Sony CD changers can be taken advantage of. I am placing to sample mixer designs on this page which you can build. The first, a passive mixer, can be made with only resistors and RCA jacks and give reasonable performance (depending on you degree of audiophility). The second circuit is a active mixer which gives very good performance and is very low noise and distortion for an active circuit. If you are capable of building it, this is a far superior circuit. Mixers are also commercially available. Most have features which are unnecessary in this application (e.g. adjustable gain on each input).

simple passive mixer which is inexpensive and easy to make. It is easily expanded to any number of players at the expense of lost gain. Only 1/2 of the circuit is shown (i.e. one for the left, one for the right). This circuit is relatively low noise and distortion, however it has the following disadvantages over an active circuit:
*The volume of each CD player drops to 1/3 it's original value (-9.5dB) with 3 players.
*You'll begin to see high frequency roll off if you have more than a few nF of cable capacitance.
The 2k resistors should be replaced with larger values if your CD player outputs are not rated for such a low impedance (each player sees 3k ohms each when all 3 players are connected). Increasing the resistance may reduce distortion from you CD player output stage, but you will begin to pay the penalty of increased noise and high frequency roll-off.
simple active mixer which is inexpensive and easy to make. It is easily expanded to any number of players. Only 1/2 of the circuit is shown (i.e. one for the left, one for the right). This circuit is very low noise and distortion. No gain is lost when connecting multiple players. Overall gain can be adjusted by changing R4. The 2k resistors should be replaced with larger values if your CD player outputs are not rated for such a low impedance (each player sees 2k ohms). Increasing the resistance may reduce distortion from you CD player output stage, but you will begin to pay the penalty of increased noise.

Luis Fernando Cantor B.
Electronica de Estados Solidos
Seccion 2

Heaven Cigar Any Good

Using your Op-Amp Circuit in the real world



Almost all active (semi-conductor or tube based) audio units add some degree of DC voltage bias. What this means is that the audio signal can have positive o r negative voltage bias - this is something that can cause large distortion errors, or other problems as you stack modules together. The easiest way to fix this is to assume that you will encounter the  problem and use a  blocking capacitor at the input and output to eliminate the DC offset.
A capacitor is used in this context to pass only the A C (Complex Waveform) component of the signal. As many of you might know, capacitors are also used in Cross-Over networks, as well as voltage storage in a power supply (to even out the voltage levels). For our use - which are circuits for audio signals at levels that are used in Microphones, Guitars, Keyboards and other electronic musical gear - there are some values that tend to work quite well. All the designs in this series will  use those values for the types of input and output stages that you would use in this environment. Yes, it is possible to optimize this area, however, for our purposes, the values that I use will do an excellent job.
One question that comes up frequently is how to pick the correct voltage part when choosing a capacitor - its quite simple - choose a part that is  as high or higher rated than the power supply. If you are using 2 9 volt batteries to drive the circuit - thats 18 volts - you'll  probably use 25 volt or higher capacitors. Never use a capacitor rated at less than the maximum voltage of the power supply. I frequently use 50 volt or 100 volt capacitors - they are often the same price and will give the same results. Don't skimp here.  One problem that you will encounter with the input stages that are Non-Inverting is that the input stage needs a ground reference. Since the capacitor won't pass the DC equivalent of ground thru the capacitor, we need to add a fairly high resistance resistor that provides the ground ref
erence for us. We don't need this on Inverting input stages because the Non-Inverting input is tied to ground and the Inverting input accomplishes the same thing by use of negative feedback. All the circuits shown here have these components in place along with the values.
In   Figure 2, you see a standard   Non-Inverting Amplifier. The circuit looks pretty similar, except that there is an extra component in the Input DC Blocking secti on - its the ground reference resistor. You'll also note that the values of   Cin   differ depending on whether you are building an   Inverting   or Non-Inverting   input stage. These values have to do with the input impedance differences. The output DC Blocking components are the same in either type of amplifier.

You'll note one additional component - that is the shorting input jack that I show f
or the   Signal In   connection. This type of j
ack is wired such that when no 1/4 inch phone jack is plugged in, the input is set specifically to signal ground. Doing this eliminates a lot of potential noise problems.

In   Figure 3   we take the 4 channel Mixer from   Part 1   and add the components needed to interface this with the outside world. The inputs are designed for high impedance devices, such as Guitars, Keyboards, High Impedance Dynamic Microphones and the like, that use single sided (unbalanced) inputs. You'll also notice that I've added a level control on each input to the mixer, otherwise, theDC blocking   section is pretty much the same as the   Figure 1   above.
    

Luis Fernando Cantor B.
Electronica de Estados Solidos
seccion 2

Troubleshooting Offline Printer

Simple Mixer Schematics


A final  word on the capacitor

There are capacitors in two main circuit functions on the schematics above. the first is an electrolytic blocking capacitor. The idea is that a DC voltage can't got through a capacitor in series. What this means is that any DC offset voltage emanating from a preceding stage or source will be knocked on the head. only the AC voltage (The audio signal) will get through. The reason for this is simple. Suppose you had 10 sources each with a +1volt DC offset. This would add up in the mixer stage to be +10 volts. Not exactly desirable. It is therefore usual to use a blocking capacitor to stop this happening. This may not be so in all cases but is a rule of thumb for most audio circuits. The blocking capacitor is placed on the input near to where an unknown source is to enter the circuit. It is also usual to have one on the output stage which blocks any DC from leaving your circuit and propagating into any following equipment. The reason you need them on both input and output is simply that you never know what you might connect your circuit up to and there is no convention. If you are unsure of the polarity required for the blocking capacitor you can use a bi-polar electrolytic. Which is essentially two normal electrolytic capacitors back to back in the one package. The value of these capacitors are not important as long as it has no effect on the audio signal (IE accidently creates a lowpass filter) and the voltage rating is sufficient enough that it won't burn out. Usually 16 volt rating is sufficient. 25 volts to be on the safe side. 50 volts is called "over-engineering". The value of the capacitor can be anywhere between 0.1uF to 47uF but usually between 1.0uF and 10uF.
The other two capacitors, 27pF and 47pF are optional and for stability of the op-amps. Truth be known these were left in the schematic by accident because I simply modified the circuit from one I was working on at the time of writing. The original circuit was designed to closely approximate another commercial mixer as I was extending it's capabilities.
Out of interest these two capacitors cause the op-amps to behave as slight intergrator-filters limiting the top end response slightly above the audio bandwitdth. This is some times necessary where the op-amps used have such a high gain-bandwitch product that they tend to saturate with RF or at least HF signals. Thus becoming unstable in certain situations. Generally speaking these are largely irrelevant to the design.

Luis Fernando Cantor B.
Electronica de Estados Solidos
Seccion 2

How To Get Effects On Webcam On Oovoo

Simple Mixer Schematics


Two more variations

The third circuit shows a Mixer with input attenuation. This is a fairly simple concept. A potentiometer is placed in the signal's path between the source and the summing resistor. When the wiper of the POT is at the top it simply represents a 10K load to the source. 10K is a pretty high value and most line level devices can easily drive this load. With the wiper at the other end of the pot it still represents a 10K load to the source but the input is effectively at ground (Shorted out) so no signal gets through. With the wiper in mid way position the input loading is still 10K, however the signal has to flow through a 5K resistance and is also dumped to ground by 5K. Halving the potential reaching the input resistor/summing node.
The fourth and final circuit shows a full on stereo mixer. Two new types of input networks are shown. the first is a stereo-in with balance. Similar to your stereo amplifier etc. A dual gain pot is use for volume whilst balance is single. Note that following the volume pot is a 10K resistor connected to one end of the balance pot. With the wiper in the centre position and connected to ground as it is, means that the incoming audio is virtually running through a 22.5K resistor to ground. That is 10K +(1/2 of 25K) = 22.5K Because of this attenuation the feedback resistor around the virtual earth op-amp is increased to 33K to compensate. This is not exactly unity gain but it comes awfully close. A very slight and probably un-noticeable gain.
The other input is MONO in but is pannable between left and right. The same deal as above applies here except that the first two 10K resistors are joined together so that the signal is split across two paths. Strictly speaking the first two 10K resistors in the stereo input are not necessary but are needed for the mono circuit so that the pan pot does not short out the signal when at either extremes of travel. They are included in the stereo input simply to compensate for unity gain over all. This input scheme is the basis for 99% of all large mixing consoles.

Epilogue  

Well hopefully I've provided enough information so you could go out and roll your own designs. And hopefully I've been able to work it in such a way that it's relatively understandable. If there are any mistakes, errors or omissions, please feel free to point them out. But Please no nit-picking. I'm only doing this because of the number of questions asked on this subject and the relative interest for people to design their own.
No responsibility is taken for any damages or any other shortcomings if you actually use this information. If you start out building one of my designs and end up wiring yourself to the national grid, it's you're problem.
Luis Fernando Cantor B.
Electronica de Estados Solidos
seccion 2