fundamental of electronics · prof. dr. fahmy el-khouly. chapter 2 diode applications series diode...
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Fundamental Of Electronics
Prof. Dr. Fahmy El-khouly
Chapter 2
Diode Applications
SERIES DIODE CONFIGURATIONS WITH DC INPUTS
Determine I , V1 , V2 , and Vo for the series dc configuration of Fig. 2.27.
Determine ID , VD2, and Vo for the circuit
.
PARALLEL AND SERIES–PARALLEL CONFIGURATIONS
Determine Vo, I1, ID1, and ID2 for the parallel diode configuration
Determine the voltage Vo for the network
Determine the currents I1, I2, and ID2 for the network
.
AND/OR GATES
Determine Vo for the network of Fig. 2.38.
Determine the output level for the positive logic AND gate of Fig.
2.41.
SINUSOIDAL INPUTS; HALF-WAVE RECTIFICATION
(a) Sketch the output Voand determine the dc level of the output for the network
of Fig. 2.48.
(b) Repeat part (a) if the ideal diode is replaced by a silicon diode.
(c) Repeat parts (a) and (b) if V is increased to 200 V and compare solutions
using Eqs. (2.7) and (2.8).m
FULL-WAVE RECTIFICATION
1-Bridge Network
Center-Tapped Transformer
Determine the output waveform for the network of Fig. 2.63 and calculate the
output dc level and the required PIV of each diode.
PIV is equal to the maximum voltage
across R, which is 5 V
CLIPPERS
When diode “on” Vo =Vi - Vdc
When diode “off” Vo= 0
Example 1
*At –ve half cycle diode is “off” then Vo=0
*At +ve half cycle there are two periods:
(i) Vi<Vdc then diode “off” and Vo = 0
(ii) Vi > Vdc then diode “on” and Vo = Vi-Vdc
Example 2
*At +ve half cycle diode is “on” then Vo=Vi+Vdc
*At -ve half cycle there are two periods:
(i) [Vi]<[Vdc] then diode “on” and Vo = Vi+Vdc
(ii)[ Vi ]> [Vdc] then diode “off” and Vo = 0
Example 3
Example 4
When diode is “on” then Vo = Vdc
When diode is “off” then Vo = Vi
At –ve half cycle diode is “on” then Vo = Vdc
At +ve half cycle there are two periods:
(i) Vi<Vdc then diode “on” and Vo = Vdc
(ii) Vi > Vdc then diode “off” and Vo = Vi
CLAMPERS
After the capacitor charged with Vc=+Vi then the diode is always “off”
and Vo=Vi-Vc
Example
After the capacitor charged with Vc=+Vi +Vdc
then the diode is always “off”
and Vo=Vi+Vc
ZENER DIODES
Zener diode equivalents for the (a) “on” and (b) “off” states