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

Determine overall power factor of the combined load, Q. Two balanced, three...

Q. Two balanced, three-phase, wye-connected loads are in parallel across a balanced, three-phase supply. Load 1 draws 15 kVA at 0.8 power factor lagging, and load 2 draws 20 kVA at

Induced voltage and inductance, Experiments conducted by Faraday and others...

Experiments conducted by Faraday and others using current carrying coils resulted in 'The Laws of Electromagnetic Induction' which state: 1)  'If the magnetic flux threading throu

Define multiplexing, 1 Explain the advantages and disadvantages of optical ...

1 Explain the advantages and disadvantages of optical fiber versus copper Medium of communication 2 Define multiplexing. Explain TDM 3 Describe the protocol architecture and

Calculate the average length of the chain, The upper end of a hanging chain...

The upper end of a hanging chain is fixed whereas the lower end is attached to a mass M. The (massless) links of the chain are ellipses with major axes and minor axes l+a and l-

Define multiple inputs - control system, Define Multiple Inputs - Control S...

Define Multiple Inputs - Control System When there is much more than one input to a system, the superposition principle can be employed. This is that: The response to variou

Compareson, compear copper and aluminum conductore in termes of price ,weig...

compear copper and aluminum conductore in termes of price ,weight,resistance for equal length .

Calculate the rated load current of machine, A 500 MVA, 33kv, three phase s...

A 500 MVA, 33kv, three phase steam turbine generator has a synchronous reactance of 1.6 p.u. It delivers a rated output at 0.8 power factor lagging. Calculate (a) The synchronou

Energy bands, Energy Bands 1) Since isolated atoms are brought togethe...

Energy Bands 1) Since isolated atoms are brought together to make a solid, the electron wave functions begin to overlap. 2) Several interactions occur, and, at the proper i

Right-handed coordinate system, The vectors we will use we be refered to ri...

The vectors we will use we be refered to right-handed Cartesian axes. Right handed means that the x,y,z axes are oriented in a particular way (which you must know). See diagrams

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