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

Octal number systems, Octal Number Systems Now the  question may  arise...

Octal Number Systems Now the  question may  arise in one mind  that why  to learn  octal  number  system when  neither  human  nor the  digital  systems  uses. It  hence it is

#signal processing, how to break a signal into time components

how to break a signal into time components

Harmonics, how harmonics shows effect on power systems?

how harmonics shows effect on power systems?

What is accelerated graphics port, What is AGP? AGP: The latest additio...

What is AGP? AGP: The latest addition for many computer systems is the inclusion of the accelerated graphics port. This AGP operates at the bus clock frequency of the microproc

Voltmeter transistor, explain basic working of voltmeter transistor

explain basic working of voltmeter transistor

Dc chopper - power supplies , DC chopper This is  one stage  conversio...

DC chopper This is  one stage  conversion  device  which is used for direct conversion of fixed  de voltage at a level to an adjustable dc voltage  at another  level.

Illustrate sources and loads, Q. Illustrate Sources and Loads? A source...

Q. Illustrate Sources and Loads? A source-load combination is represented in Figure. A node is a point at which two or more components or devices are connected together. A part

Clapp oscillator, derivation of frequency of oscillators clapp and derive C...

derivation of frequency of oscillators clapp and derive C effect?

Voltage breakdown Diode, Help me, i need some answer regarding Voltage brea...

Help me, i need some answer regarding Voltage breakdown. What formula do I use?

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