lecture (04) diode applications idraelshafee.net/fall2019/electronic-circuits-i---lecture-04.pdf ·...
TRANSCRIPT
![Page 1: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/1.jpg)
By:
Dr. Ahmed ElShafee
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I1
Lecture (04)Diode
Applications I
• The Complete Diode Model
• Add a small forward dynamic resistance (r’d) and the large internal reverse resistance (r’R).
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I2
![Page 2: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/2.jpg)
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I3
•
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I4
![Page 3: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/3.jpg)
Example 01
•
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I5
• Complete model
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I6
![Page 4: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/4.jpg)
Example 02
•
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I7
• Complete model
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I8
![Page 5: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/5.jpg)
The Basic DC Power Supply
• All active electronic devices require a source of constant dc that can be supplied by a battery or a dc power supply
• dc power supply converts the standard 220V, 50Hz ac voltage available at wall outlets into a constant dc voltage
A basic block diagram of the complete power supply9
• Stage 1: transformer changes ac voltages based on the turns ratio between the primary and secondary.
• Stage 2: rectefire (half wave) The rectifier converts the ac input voltage to a pulsating dc voltage,
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I10
![Page 6: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/6.jpg)
• Stage 3:The filter eliminates the fluctuations in the rectified voltage and produces a relatively smooth dc voltage.
• Stage 4: The regulator is a circuit that maintains a constant dc voltage for variations in the input line voltage or in the load.
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I11
Half wave rectifier
• When the sinusoidal input voltage (Vin) goes positive, the diode is forward‐biased and conducts current through the load resistor
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I12
![Page 7: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/7.jpg)
• When the input voltage goes negative during the second half of its cycle, the diode is reverse‐biased.
• There is no current, so the voltage across the load resistor is 0 V,
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I13
• The resulted voltage drop across load is stimulating DC voltage
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I14
![Page 8: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/8.jpg)
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I15
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I16
•
![Page 9: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/9.jpg)
Example 01
• What is the average value of the half‐wave rectified voltage in Figure
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I17
•
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I18
![Page 10: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/10.jpg)
• Effect of the Barrier Potential on the Half‐Wave Rectifier Output
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I19
• It’s acceptable to neglect the effect of the barrier potential, when the peak value of the applied voltage is much greater than the barrier potential (at least 10 V, as a rule of thumb).
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I20
![Page 11: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/11.jpg)
Example 02
• Draw the output voltages of each rectifier for the indicated input voltages, as shown in Figure. The 1N4001 and 1N4003 are specific rectifier diodes.
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I21
•
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I22
![Page 12: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/12.jpg)
• Peak Inverse Voltage (PIV)
• equals the peak value of the input voltage, and the diode must be capable of withstanding this amount of repetitive reverse voltage
• A diode should be rated at least 20% higher than the PIV.
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I23
• Transformer Coupling
• transformer is used to couple the ac input voltage from the source to the rectifier,
• Advantages:
– Step down voltage
– electrically isolated rectifier, thus preventing a shock hazard in the secondary circuit.
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I24
![Page 13: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/13.jpg)
• turns ratio
• If n < 1, then Vsec <Vpri.
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I25
Example 03
• Determine the peak value of the output voltage for Figure, if the turns ratio is 0.5.
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I26
![Page 14: Lecture (04) Diode Applications Idraelshafee.net/Fall2019/electronic-circuits-i---lecture-04.pdf · voltage and produces a relatively smooth dc voltage. • Stage 4: The regulator](https://reader031.vdocuments.mx/reader031/viewer/2022011816/5e76e885365eda74506a8953/html5/thumbnails/14.jpg)
•
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I27
Thanks,..
See you next week (ISA),…
Dr. Ahmed ElShafee, ACU : Fall 2019, Electronic Circuits I28