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

Power system, recent trends in power system

recent trends in power system

Explain electric polarization, Explain electric polarization. Electr...

Explain electric polarization. Electric polarization : This polarization density is the vector field such expresses the density of permanent or induced electric dipole momen

Event triggering, what is event triggering related to digital storage oscil...

what is event triggering related to digital storage oscilloscope?

What is signal multiplexing, Q. What is Signal Multiplexing? Frequency-...

Q. What is Signal Multiplexing? Frequency-division multiplexing (FDM) and time-division multiplexing (TDM) systems. When data from many sources in time are interlaced, the inte

Magnetism, with the aid of the diagram explain the following rules that can...

with the aid of the diagram explain the following rules that can be used to determine the direction of magnetic fields around a current carrying conductor (1)cork screw rule (2)rig

Frequency response of your amplifier, a) What is meant by frequency respons...

a) What is meant by frequency response and how would you check the performance of your amplifier? b) Calculate the Voltage Gain of your amplifier at a range of frequencies suffic

Find transmission bandwidth required of telemetry system, Find the transmis...

Find the transmission bandwidth required of a data telemetry system that is to handle three different signals with bandwidths W 1 = 1 kHz, W 2 = 2 kHz, and W 3 = 3 kHz, by emplo

Evaluate hysteresis loss, Q. A magnetic circuit is found to have an ac hyst...

Q. A magnetic circuit is found to have an ac hysteresis loss of 10 W when the peak current is Im = 2 A. Assuming the exponent of Bm to be 1.5, estimate Ph for Im = 0.5A and 8A.

Sketch a typical circuit for a 2-input 4-output decoder, Q. Sketch a typica...

Q. Sketch a typical circuit for a 2-input, 4-output decoder.

Why are waveguides not used at low frequencies, Q. Comment brie?y on the fo...

Q. Comment brie?y on the following: (a) Why are waveguides not used at low frequencies? (b) Why are open-wire lines not generally used as guiding structures at very high freq

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