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

Block diagram of a 4-bit shift-right register using jkffs, Q. A shift regis...

Q. A shift register can be used as a binary (a) divide- by-2, and (b) multiply-by-2 counter. Explain. Q. Show a block diagram of a 4-bit shift-right register using JKFFs.

Determine the slip at maximum torque, A three-phase induction motor, operat...

A three-phase induction motor, operating at its rated voltage and frequency, develops a starting torque of 1.6 times the full-load torque and a maximum torque of 2 times the full-l

The three-phase alternator, The Three-phase alternator In this case, t...

The Three-phase alternator In this case, three separate sets of coils are wound on the stator and connected to produce three separate outputs. Because of the physical displace

Example register to memory , Example  Register  to Memory Example ...

Example  Register  to Memory Example : Write assembly language  statement  to copy 25H  stored  in register D to memory location 3052H. Solution :   Assuming  3050H is s

Performance benchmarking through indicators, Performance Benchmarking throu...

Performance Benchmarking through Indicators There are various indicators techniques for benchmarking. It is also not probable to benchmark all the indicators, collect and ana

Explain about automatic stabilizers, Q. Explain about Automatic Stabilizers...

Q. Explain about Automatic Stabilizers? Automatic Stabilizers: Government fiscal policies which have effect of automatically moderating cyclical ups and downs of capitalism.

Explain indexed addressing in 8051, Probelm: (a) Explain indexed addre...

Probelm: (a) Explain indexed addressing in 8051. (b) How does the 8051 distinguish between a byte address and a bit address? (c) How do open-loop and closed loop appli

Estimate the bandwidth by using carsons rule, Let a message signal m(t) hav...

Let a message signal m(t) have a bandwidth of 10 kHz and a peak magnitude of 1 V. Estimate the bandwidth, by using Carson's rule, of the signal u(t) obtained when m(t) modulates a

Conditions in which rc circuit behaves as integrator, Q. Explain the condit...

Q. Explain the conditions under which an RC circuit behaves as Integrator? Integrator is a circuit in which the output voltage is proportional to the integral of the input. Out

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