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

Water flow mangemen using embeded technogy, what is the method to do this p...

what is the method to do this project and what material used for?

Find the expressions for the inductor current, Consider the RL circuit of F...

Consider the RL circuit of Figure with R = 2, L = 5H, and v(t) = V = 20 V (a dc voltage source). Find the expressions for the inductor current i L (t) and the inductor voltage v L

Describe binary number system, Q. Describe binary number system? The bi...

Q. Describe binary number system? The binary number system has a base of 2 with two distinct digits (bits), 1 and 0. A binary number is expressed as a string of 0s and 1s, and

Determine the bounds on the carrier frequency, Suppose that a video signal,...

Suppose that a video signal, having W = 5 MHz, is transmitted via FM with f = 20 MHz. For 1/100 ≤ B/fc ≤ 1/10, determine the bounds on the carrier frequency. Use WFM ∼ = 2( ω + 2W

Explain working of bipolar junction transistors, Q. Explain working of Bipo...

Q. Explain working of Bipolar junction transistors? The family of bipolar junction transistors has two members: the npn BJT and the pnp BJT. Both types contain semiconductor ju

Full wave bridge rectifier circuit , Construct a full wave bridge rectifier...

Construct a full wave bridge rectifier circuit and connect it to the transformer output. What is the Output Voltage and Frequency?

Rectifier, wave form of half wave rectifier with rl load

wave form of half wave rectifier with rl load

What is induction machines, Q. What is Induction machines? We shall fir...

Q. What is Induction machines? We shall first consider polyphase induction motors and then single-phase induction motors. The polyphase induction motors used in industrial appl

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