Our professor requested for a project proposal (any category of project would do as long as doable by a regular student) that includes these circuits.

1. Diode/Transistor Switching
2. IC Operational Amplifiers in Switching Ckt.
3. Schmitt trigger/comparator ckt.
4. Multivibrator
5. IC/Logic Families
6. Timer Ckt.

Thanks in advance.

 

It has to use all of them? Some kind of PWM control would include quite a few but a reasonably sized student project probably won't include all of them unless deliberately stretched to make it meet the requirements. For example it would be unusual to make a discrate or op-amp based schmitt when you are also using logic, etc.

I would suggest something like a 3 op-amp PWM system with one as a linear ramp generator and one as a schmitt making a triangle/square oscilator (so there's your multivibrator as well, that's any square-wave output oscillator not just the common two-transistor thing). The 3rd op-amp acts as a comparator to get your PWM and you could drive a transistor switch and maybe control it with some logic and timers.

 

Is there any instance that any of the circuits can be used for security systems? Not all circuits at the same time.

 

I think the key part of the assignment is for YOU to stretch YOUR mind and think of possible ways in which these circuits could be combined to form a project. You've taken the first step in that direction by focusing on a security system. So now sketch out what youi envision a security system (doesn't have to be fancy or even particularly realistic) might involve in terms of functions. For instance, you need some way to detect when an intruder trips an alarm, you need some way to arm and disarm the alarm, you need some way to sound an alert. Just those three things alone suggest several ways in which all of your six categories could be used.