[SOLVED] Need project idea Using OP AMP 741 c

[GURMEET singh]

My teacher gave me a project using 741c Operational amplifier but i have no idea what project should i make?
please suggest some.....

 

[Audioguru]

A lousy old 741 opamp design is 46 years old. The opamp has such poor specifications that it should be buried.

An opamp can be used in thousands of circuits. Look at OPAMP CIRCUITS in Google Images (but it has no oscillators).

 

[LvW]

My teacher gave me a project using 741c Operational amplifier but i have no idea what project should i make?
please suggest some.....

Although the 741 type is rather old - it can be used, of course, for such a beginners project.
My recommendation: Try to realize a simple integrating unit. You will see (and learn) that and why it does not work like an ideal integrator.
Then, you will learn (google/literatur search) how to modify the circuit to become a working system. Finally, you could find out between which frequency limits the circuit can be considered as an integrating unit.

 

[GURMEET singh]

A lousy old 741 opamp design is 46 years old. The opamp has such poor specifications that it should be buried.

An opamp can be used in thousands of circuits. Look at OPAMP CIRCUITS in Google Images (but it has no oscillators).

I am thinking of making a 24v DC fan control using op-amp.But i dont know how?

 

[Audioguru]

A 741 opamp cannot drive a fan but it can drive a power transistor that can drive a fan. The transistor acts like a variable resistor in series with a DC fan.

But a resistor in series with a DC motor reduces its torque so it might not start running when its speed and torque are turned down.
Pulse-width-modulation is usually used to control the speed of a DC motor because the width of the pulses control the speed due to their average voltage and the torque is always high because each pulse delivers maximum voltage.
A lousy old 741 opamp is too slow to be used for pulse-width-modulation unless the frequency is low enough to be heard as a whine from the fan. Usually pulse-width-modulation uses a frequency that is higher than we can hear.

Make the simple circuit with a 741 opamp driving a power transistor and show your teacher that the fan does not start running unless the speed is set fairly high. Tell your teacher that you will explain why the fan did not start running in the simple circuit and show that the fan starts running in a pulse-width-modulation circuit when the speed is set slow in a few years after you learn about pulse-width-modulation circuits.

 

[code_slave]

Google is your friend……

'op amp 741 mini projects'

https://www.electroschematics.com/tag/741-circuits/
https://www.eleccircuit.com/automatic-light-switch-using-ic-741/
https://bestengineeringprojects.com/operation-amplifier-741-based-projects/

you will find 'fan controls' and others at the above links.

 

[Audioguru]

Yes, most circuits simply turn the fan on and off without speed control.
Electroschematics has the first two circuits using a 741 opamp as a comparator but the circuits are missing important hysteresis which can be provided by adding one resistor. One of the circuits uses a transistor as an emitter-follower so the fan barely gets enough voltage so it runs slowly.