Observing input output waveform rectifiers
Observing input output waveform rectifiers are explained on the basis on direct current and alternating current.Firstly rectifiers convert alternating currents (AC) into direct currents (DC) . Alternating current reverse direction of each cycle while direct current moves only in one direction .the basic component that makes the rectifier work is the diode .The Observing input output waveform rectifiers of these small devices are like one way valves , they allow current to flow only in one direction .There are three basic types of observing input output waveform rectifiers : Half wave , Full wave and Full wave bridge.
OBSERVING INPUT OUTPUT WAVEFORM HALF WAVE RECTIFIERS:
When the input signal is positive , the diode is forward biased and conducts current .When the input signal is negative the diode is reverse biased and does not conduct current. Hence the output waveform V(out) is obtained. This is called “half rectified sine wave”.
- OBSERVING INPUT OUTPUT WAVEFORM FULL WAVE RECTIFIERS :
During the positive half cycle of the input signal, the diode D1 is forward biased and the diode D2 is reversed biased. Hence the current flows through D1 and R .
During the negative half cycle of the input signal ,the diode D1 is reverse biased and the diode D2 is reversed biased.Hence the current flows through D2 and R.
- OBSERVING INPUT OUTPUT WAVEFORM FULL WAVE BRIDGE RECTIFIERS :
During the positive half cycle of the input signal,the diodes D1 and D2 are forward biased and D3 and D4 are reverse biased.So the current flows from diode A to B over diode D1,to C over R , to D over D2 and back to A over the secondary winding of transformer.
During the negative half cycle of the input signal , the diodes D3 and D4 are forward biased and D1 and D2 are reverse biased. So , the current flows form F to D and B over D4 , to C over R , to A over D3 and back to A on the secondary winding of transformer.
SOME IMPORTANT QUESTION AND ANSWERS BASED ON INPUT AND OUTPUT WAVEFORM OF RECTIFIER :
Q 1) WHAT IS THE WAVEFORM OUTPUT OF FULL WAVE RECTIFIER?
Ans 1)Basically it is having a hump for 1/2 a cycle then zero voltage for 1/2 a cycle then anothr hump and so on .Sine wave goes above and below the zero voltage level.
Q 2) WHAT IS THE DIFFERENCE BETWEEN FREQUENCY OF THE OUTPUT THE INPUT VOLTAGE WAVEFORM s FOR HW AND FW RECTIFIER CIRCUIT?
Ans 2)HW is twice as long as FW rectifier because HW rectifier is one wavelength is half wave followed by half zero amplitude wave .
Q 3)WHY THE OUTPUT WAVEFORM AT SUMMING AMPLIFIER IS OUT OF PHASE OF 180 WITH INPUT SIGNAL ?
Ans 3)This is because we are using inverting amplifier , It will cause an apparent 180 degree phase shift .
Q 4)Explain forward break over voltage ?
Ans 4)It is the forward at which SCR switches on and begin to conduct,when gate current is zero.It is the forward blocking region when the forward voltage is less than V (Fbo).
Q 5)Explain the concept of holding current ?
Ans 5)It is minimum forward anode current required to be maintained to keep scr on . If scr is conducting and falls below holding level and turns it off.