Hello,
I found these boards while searching google for a project so I thought I would ask you knowledgeable folks for some direction. I am a university physics student taking an introductory electronics class required for my degree. I need to find a simple circuitry project using basic components. Nothing too fancy or expensive. We have gone over basic analog circuitry and basic digital circuitry but I am willing to teach myself a little bit if I find something interesting that I have not yet encountered. I would like to do something that will actually have some sort of use rather than sitting on my desk for the next few years before being thrown out. I was wondering if any of you could tell me a good resource for finding something to build.
Thanks much!

 

We have an experiments section in the AAS Ebook - http://www.allaboutcircuits.com/vol_6/index.html.

The Projects section has any number of hobby projects in it. And Googling "hobby circuits" should bring up a lot of hits.

We could probably make less vague suggestions if you could state an interest.

 

Since Physics is the science of measurement (amongst other things I don't want to generate a definition argument here) something measurement related could be indicated.

First line of attack might be to do with transducers, which introduces interfacing techniques, op amps and their circuitry, analogue/digital conversions and counting. perhaps a magnetometer or geiger counter? Or perhaps earth resistivity measurements for geophysical purposes?

If you want to do more electronic stuff look at multivibrators in general. Studying the design of these (astable, monostable and bistable versions) allows you to get an appreciation of both analog and digital circuitry at the basic level. Building a two transistor multivibrator allows study of amplifier, pulse , counting, shaping, timing, sequencing and triggering circuits.

Google these terms and you will find loads of examples.

 

If measurement is wanted, I'd start with these two:

http://www.allaboutcircuits.com/vol_6/chpt_4/6.html

http://www.allaboutcircuits.com/vol_6/chpt_4/7.html

...and replace the headphones with some kind of metering circuit. I think it's fun to measure things which can't bee seen.

That's just me, of course.

 

Following my earlier post, the attached circuit, due to Marston et al, combines all the electronics introductions I mentions and the constructor ends up with a useful piece of test gear.

With the switch in position 1 the two transistors are connected as a free running astable multivibrator at about 1Khz. This can be injected at the probe tip into circuits.

Position 2 switches the two transistors to form a multistage amplifier, which can trace signals picked up on the probe tip. These can be heard on the earpiece.

Position 3 is off.

I'm hoping someone will tell me how to get and use LaTex so I can upload better quality drawings, but that is for another thread.

 

Thanks for the replies! It looks like I have a good start and should be able to find something with what you all have provided. Thank you again!