Schematic symbols, Electrical Engineering

Assignment Help:

Schematic Symbols

The junction gate field-effect transistor or JFET gate is sometimes drawn in the middle of the channel (in place of at the drain or source electrode as in these illustrations). This symmetry suggests that "drain" and "source" are interchangeable, thus the symbol should be used just only for those JFETs where they are indeed interchangeable (that is not true of all JFETs).

Formally, the style of the symbol should depict the component inside a circle (presenting the envelope of a discrete device). This is right in both the US and Europe. The symbol is generally drawn without the circle while drawing schematics of integrated circuits. More recently, the symbol is frequently drawn without its circle even for discrete devices.

In each case the arrow head depicts the polarity of the P-N junction formed in between the channel and gate. The arrow points from P to N, the direction of conventional current while forward-biased as with an ordinary diode. An English mnemonic is that the arrow of an N-channel device "points in".

To pinch off the channel, it requires a certain reverse bias (VGS) of the junction. This "pinch-off voltage" changes considerably, even among devices of similar type. For instance, VGS (off) for the Temic J201 device varies from -0.8V to -4V. Typical values change from -0.3V to -10V. To switch off an n-channel device needs a negative gate-source voltage (VGS). On the other hand, to switch off a p-channel device needs VGS positive. In usual operation, the electric field developed through the gate must block conduction in between the source and the drain.


Related Discussions:- Schematic symbols

Sparking with electrical equipment, Sparking : In ordinary domestic situat...

Sparking : In ordinary domestic situations, small electrical sparks are usually not hazardous. In certain conditions which are frequently encountered in science labs, even the sma

Input voltage to system and the output motor speed, A system contains an am...

A system contains an amplifier with a gain of 10 offering the armature voltage for a motor which provides an output speed which is proportional to the armature voltage, the constan

Power system engineering, A three-phase transposed line is composed of one ...

A three-phase transposed line is composed of one ACSR conductor per phase with flat horizontal spacing of 11 meters as shown in Figure (a). The conductors have a diameter of 3.625

When input is a triangular wave, Q. When input is a triangular wave. W...

Q. When input is a triangular wave. When the input fed to differentiating circuit is a triangular wave, the output will be a rectangular wave. During the period OA of

Variations of drain current - drain voltage, Q. Consider the common-source ...

Q. Consider the common-source JFET circuit shown in Figure with ?xed bias. Sketch the sinusoidal variations of drain current, drain voltage, and gate voltage superimposed on the di

Give illustration of and and or gate - microprocessor, Give Illustration of...

Give Illustration of AND and OR Gate - Microprocessor? Illustration: The image below demonstrate the 4 possible inputs into a 2-input AND gate and all the corresponding outputs

General purpose diodes - types of power diodes , General Purpose Diodes ...

General Purpose Diodes The  general purpose  diodes  have relatively high reverse recovery time. The  diodes are general  made  by diffusion. They  are used  in low  speed  app

Cross-subsidy and multi-year tariff - electricity policies, Cross-subsidy:...

Cross-subsidy: The policy gives clarity on determination of cross-subsidy and additional surcharges for open access to consumers and lays down a timeframe for rationalization

Requirement of a hybrid in telephone networks, Q. What is the requirement o...

Q. What is the requirement of a hybrid in telephone networks? How does it work? Ans: Digital exchanges require receive and transmit signals on separate two-wire circuits. Th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd