Help needed pn creating class ab amplifier

Thread Starter

balabalabala

Joined Nov 22, 2009
1
Can anyone pls explain about how to design this circuit..
===========================================

You must design and build an amplifier with the following characteristics:
1) At least 0.5W output power when used with a 4Ω load, vi = 200mVpk
@100Hz
2) DC power supply of +/- 5V or less
3) Minimize distortion
You must also desig an amplifier with the following characteristics:
1) At least 0.5W output power when used with a 4Ω load, vi = 10mVpk
@100Hz
2) DC power supply of +/- 5V or less
3) Minimize distortion
You must use the parts you are given. If you feel your design would benefit from
additional resistors, you may use them once you have justified your request to the
course instructor. Your justification must include a design that uses only the given
components, along with the improved design that uses the values you are
requesting; you must be able to fully explain both designs.
Along with your components, you will be provided one breadboard per group.
Please return both, the component package, and breadboard, at the end of the
course. You will have to provide the connecting wires you need and power supply
and/or batteries.
You must supply a Multisim / OrCad simulation, input output transfer function
showing the frequency dependency, bandwidth and gain, and 3dB frequencies.
You must also supply the hand calculations showing the DC current and voltage
values and relevant impedances (including the input and output resistances).

List of components, i have
======================
Class AB/B 1/2W, Class A 1/4W BJT Amplifier Kit
200mVpk @100Hz, 4ohm load (8ohm speaker)

Sayal Part Number Description No needed

MJE210-1 MJE 210 PNP 5A BJT 1
MJE182-1 MJE182 NPN 3A BJT 1
HEJH-1933-4 heatsink 2
MPS6521-5 MPS6521 NPN 100mA BJT 1
MPS3638-5 MPS3638A PNP 300mA BJT 5
1N914B-10 silicon diodes, 300mA 2
CER-255-5 electrolytic cap, 100uF, 16V 2
CETH-4744A-1 bipolar cap, 47uF, 50V 2
CTR-2577-1 cap tantalum 33uF, 20V 1
RAB-194-10 6k2 resistor, 1/4W 1
RAB-213-10 39k resitor, 1/4W 5
RAB-470R-100 470ohm resitor, 1/4W 1
? 1k resitor, 1/4W 6
? 2k2 potentiometer, screwdriver adjustable, value not critical 1
? 8ohm speaker, 1W 1
? 741 opamp 1
? 19k 1
? 4M 1
? 200k 1
? 10k 1
? 0.1uF, 30V 1
? 0.01uF, 30V 1


Thanks in advance
 

SgtWookie

Joined Jul 17, 2007
22,230
This certainly sounds like a homework problem assigned by an instructor/teacher/professor.

It really belongs in the Homework Help forum.

Post your schematic as it is currently.

Your teacher/professor/instructor must have already covered the elements of amplifier construction, or you would not have received this assignment.

You must have some idea of how to begin, or else you have been sleeping in class and neglecting your homework.

We cannot do it for you. However, if you show what work you have accomplished so far and are truly "stuck", we can help you.

If you don't even know where to start, then you will be re-taking the class/course next semester.
 

studiot

Joined Nov 9, 2007
4,998
Can't imagine why they'd use the ancient 741 considering Sayal is in Ontario Canada. We do have modern parts up here eh
Since the required frequency of operation is 100Hz a 741 is entirely appropriate.

Hint to the OP the 741 is unecessary for part 1. Why would you use it in part 2?
 
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