Static v- i characteristics - power semiconductor devices, Electrical Engineering

V- I Characteristics

The operation of the  diac can be explained by imagining it as two diodes connected  in series. When  applied voltage in either polarity is small ( less than break over voltage) a very  small amount  of current called the  leakage current flows  through the diac. Leakage  current caused due to the drift of  electrons and holes in the depletion region is not  sufficient to cause conduction in the device. The device remains in non conducting mode. How ever when T1 is positive with  respect to T1 the layers P-N-P-N starts conducting only  when applied  voltage of T1 exceeds break over voltage  V boi . once the conduction starts the current through the diac becomes very  large  and has to be limited by the external resistance in the circuit.

When T2 positive  with respect to Tp  the layers P-N-p-N  conduct. This happens when the applied voltage of T2 exceeds break over voltage  V Bo2. In both  the cases the current during  blocking regions are small  leakage current . the  behaviour  in both  the directions are  is similar  because doping level   is same in all the  layers in tow directions. The break  over  voltage  for commonly  used  disc is about 30v.

When T1 is positive  and voltage  is less than Vbo1 only a small  leakage current  flows  through  the device. When voltage  exceeds  Vboi it starts  conducting and  current  becomes  large. As the current increase the voltage  drop  across diac decrease.  Thus  it exhibit negative resistance characteristics. The  characteristics of diac  in reverse direction when  T2  is positive  lies in  the third quadrant and is  exactly similar to that in the first  quadrant. The break over voltage  VBOi and V Bo2 are exactly equal in magnitude. In both  the cases the device exhibits negative  resistance behaviours  during  conduction  region. Diac is mainly used for triggering triacs.

Posted Date: 4/2/2013 7:14:19 AM | Location : United States







Related Discussions:- Static v- i characteristics - power semiconductor devices, Assignment Help, Ask Question on Static v- i characteristics - power semiconductor devices, Get Answer, Expert's Help, Static v- i characteristics - power semiconductor devices Discussions

Write discussion on Static v- i characteristics - power semiconductor devices
Your posts are moderated
Related Questions
For the 3 bus system shown below all values are given in pu on a 100MVA base (a) Use Matlab functions lfgauss and lfnewton to find power flow solution for the system, accurate

explain the waorking principle of function generator

Characteristics of Common Source Amplifier At low frequencies and by using a simplified hybrid-pi model, the following small-signal characteristics can be derived.

Explain cascading of multiple PICS 8259.  The 8259A adds 8 vectored priority encoded interrupts to the microprocessor. It can be expanded to 64 interrupt requests by using one

Q. Consider an RL series circuit excited by (a) v(t) = 20e -2t V, and (b) v(t) = 20 V. Determine the forced component of the voltage across the inductor for R = 2  and L = 2H.

Draw an electrical relay diagram rung showing a N/O contact of CR1(coil) in series witha N/C contact of CR2(Coil), operating a lamp L1. A delay-on (TON) relay has a preset of 5.

Explain Polymers and their applications. Polymeric materials or plastics contain a large group of organo or organic metallic high molecules compound. The common properties of s

Q. What is Idss. What are the conditions for its maximum value? The term 'Idss' refers to saturation condition of the Drain current. From the above graph it's clear that as the

Q. The power gain of an antenna is 10,000. If its input power is 1 kW, calculate the maximum radiation intensity that it can generate.

Q. Explain the high-frequency response of FET amplifier?  The analysis for the high frequency response of the FET amplifier is almost the same as that of the BJT amplifier. The