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

Define electrical energy, Electrical energy If the power is measured in...

Electrical energy If the power is measured in watts and the time in seconds then the unit of energy is watt- seconds or Joules.

Digital electronic, What are the advantages of wired-AND connection of digi...

What are the advantages of wired-AND connection of digital IC

Inquire, how we can say that 3 phase induction motor is short curcited pra...

how we can say that 3 phase induction motor is short curcited practically?

Find the total per-phase inductance, A 300 km, 3-phase, 50Hz transmission l...

A 300 km, 3-phase, 50Hz transmission line has spacing as shown in Figure. Each phase of the line consists of a bundle of three conductors. (a) Find the total per-phase inductanc

Sensor selection, Research and recommend a sensor for a real full size conv...

Research and recommend a sensor for a real full size conveyor system of approximately 1000mm width to detect objects of varying size passing along it. Discuss the suitability of th

Magnet, Magnetic materials

Magnetic materials

Stator current control methods - motor control , Stator  Current Control ...

Stator  Current Control Methods The torque  and speed  of an induction motor  can be  controlled  by the  stator  current  the motor  behaviour  is different from that with VS

Fields winding - motor control , Fields Winding It produces the workin...

Fields Winding It produces the working  flux, this is also  called exciting winding.

Lc circuits, L=0.0053nH, C=15µF find the operating frequency of series LC c...

L=0.0053nH, C=15µF find the operating frequency of series LC circuit. What factors decides capacitance ..

Determine rms and average value, Determine RMS and average value: Dete...

Determine RMS and average value: Determine RMS and average value of the output of half wave rectifier. Solution The waveform of current, output of the half wave rectif

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