Project ideas?

[Jon86]

I'm an A-Level Electronics student and I'm coming up to the point where I need to pick a project. I know A-Level is quite low on the spectrum of knowledge, but I'd like to think I know a bit more than I need to (without trying to sound too pompous). Anyway, we can't use any microcontrollers, but we can use digital logic, analog chips, anything that we don't have to program, basically.
I'd like to do something analog, so I was thinking along the lines of:

Geiger Counter (A little simple, but fun)
Electronic load (Constant power maybe?)
Capacitance meter (Charge/Discharge with RC Constant calculation, maybe a bit difficult without micros?)
Amplifier of some sort
High-Power LEDs that respond to music

I'm not sure really, so any ideas welcome! 
Thanks in advance

[Kryoclasm]

How about an Analog multimeter?   

[Jon86]

Hmm, Analog frontend, constant current for resistance and maybe even an inductance circuit... Sounds good!

[madshaman]

Sounds like you want difficulty.  How about a 100W class B (A/B) power audio amplifier with a linear response.

[Jon86]

I do want difficulty, but I don't really have enough experience with amps to design one myself. Its a possibility though if i read up on it, thanks

[madshaman]

Could also do magnetic levitation, you could use a simple feedback control loop or go for a PID controller implemented in analog?

[Jon86]

Thanks, that sounds really good
Oh and by the way, it looks like I'm limited to 50V and for some reason 50W?

[Tranan]

How about a magnetic field meter. (Tesla meter) 

[Noize]

Try and find the  characteristic impedance of the average death row prisoner so you can get maximum power transfer. Discuss various material properties of the electric chair. Pros and cons. Post the power point presentation here. Sorry I'm bored. No even better. The technology behind IED's planted under tutors cars that give low marks.

[Noize]

Seriously the geiger counter one isn't simple if you go into the physics of the detector.

Edit: Could get top marks there especially in conjuntion with second suggestion.

[madshaman]

Thanks, that sounds really good
Oh and by the way, it looks like I'm limited to 50V and for some reason 50W?

Here's a nice tutorial (on magnetic levitate with a simple control loop) by Shahriar who publishes "the signal path" video blog: http://thesignalpath.com/blogs/2013/01/28/tutorial-and-experiments-on-magnetic-levitation/

I don't know Shahriar, but really enjoy his blog.

If you want to do this, make *sure* you order a Hall effect sensor with *analog* output, the majority of sensor will have threshold/digital output.

[Jebnor]

High-Power LEDs that respond to music

How about an audio spectrum analyzer? An analyzer which has an LED bar graph for each frequency range. I believe it can be done within your restrictions and it may give you good experience with both Analog and digital components.

[dimircea]

What about a 4bit/8bit computer by using only transistors, buffers and discrete components ? If you like difficulty, make it to output not by using simple LEDs but a sort of AV output (probably monochrome)...or even better, a LEDs matrix with two colors or even RGB.

You can use switches to program it and LEDs (or other method) for output.

[seanhaz]

a logic robot? similar to this, you could make it more complex

[ElectroWarrior]

For me building a metal detector was really fun. Even though the project might sound a bit ambiguous it contains a great amount of really interesting theory that you really get to feel, see and hear. It is not often in electronics that you actually are able to "see" the electricity or electromagnetic waves - when i built a metal detector I got a more intimate relationship with magnetic waves, and how resonance really works.. made things for me more intuitive. There is a lot of great tutorials out there, and it can be build by analog and gates only:)
A bit reading material:
www.wikihow.com/Build-a-Metal-Detector
http://www.electroschematics.com/6616/homemade-metal-detector/

Best regards
ElectroWarrior

[bitluni]

how about an sound synthesizer.

you can scale the difficulty yourself. analog wave generation square, triangle, sine...
frequency control and sequencing using MCU and some basic amp for a phones jack.
some LEDs buttons and you will get a high entertainment factor. 

[Jon86]

Great ideas, thanks! The project restrictions are bloody awful, it's pretty much narrowing it down to a few generic chips sitting on a breadboard... Apparently I need four different chips at least, and nothing programmed at all... Ah well, I could have a go at the sound synthesizer / function generator, the magnetic stuff looks good too 

[Jon86]

I'm not sure about the logic stuff, I'll keep it in the 'maybe' pile, but I just get so bored of all the logic gates...