circuit analysis help

[bengalab]

Can anyone please give me a brief description of how this circuit works? The minimum I need to know is the general purpose of each op amp section of the circuit. Thank you.

 

[Hero999]

We don't mind helping you but we won't do all of the work for you. Please post what you've already done including any ideas you've had and we might be able to make some suggestions. If you've got completely no idea then may be it's your lecuturer's fault and it isn't right that you make him/her look good by cheating and copying from the Internet.

 

[Russlk]

What? No integrator?

 

[audioguru]

What? No integrator?

The very old LM324 has a bandwidth so low that it is an integrator. It turns frequencies above about 10kHz into triangle-waves.

I noticed that the high impedance of the output of the photo-transistor is heavily loaded-down by the very low input impedance of the 1st opamp beacause it is an inverting circuit. DUMB!
If the 1st opamp was non-inverting then it would have a high input impedance that won't load-down the photo-transistor.

 

[mneary]

Can anyone please give me a brief description of how this circuit works?

The circuit works badly.

 

[Gayan Soyza]

To turn an output ON and OFF due to the light sense do you need all 4 stages????

You don’t need all four stages.

I think this can be done in a simple OP Amp or Comparator IC’s like LM358, LM311 etc….

[Sensor – Comparator – output ]need only one stage.

If you make a try this can be done in 555 IC too.

 

[Hardwire]

Can anyone please give me a brief description of how this circuit works? The minimum I need to know is the general purpose of each op amp section of the circuit. Thank you.

Several of the answers you need can be found by studying this document:

https://www.electro-tech-online.com/custompdfs/2007/05/LM124.pdf