Applied physics student, want to get deeper into electronics

Thread Starter

sudointellectual

Joined Sep 28, 2013
5
I'm attending an applied physics program that is basically an EE program with less electronics. Attending a course covering the very basics - dc, rlc and simple filters, basics of op-amps, ad/da...

We're also doing signal and control systems related stuff as well as digital design, but this is basically the only course we're getting wrt analog stuff etc apart from electives.

So what would be a good next step for someone who wants to gain a deeper understanding of the analog part? How did you guys progress? Where should my attention be right now?
 

#12

Joined Nov 30, 2010
18,224
Get some parts and connect them to make circuits. The act of connecting the parts will reveal all the weaknesses in your education and any misguided assumptions you might have picked up. Electrons can not lie. They must obey the laws of physics. They make an unmerciful teacher. When you can get the light to blink, you will know you have at least followed the instructions. Not far after that, you will know why it had to be done that way.

Any, "electronics projects for dummies" will do. The point is, you must get your hands on some parts and get them to do what you want.
 

WBahn

Joined Mar 31, 2012
30,082
In general I agree fully with #12 on this. The best way to learn something is to do something. It does not have to be fancy.

The old "Night Rider" project is actually pretty wonderful and can be done incrementally and in a lot of different ways. Get a single LED to blink on and off. Then get two LEDs to alternate. Then get three LEDs to sweep back and forth. Then go for four and so on up to about seven or so.

You can do this all in analog, all in digital, or in some mix of the two. As you go try to decide on more subtle and interesting effects. At first you will almost certainly have one LED turn off and then the next LED turn on and you may have the LEDs turn abruptly on and off. Try making them so that the fade in and out and so that one is turning off while the next is turning on. Some of these effects you will discover are very easy to do in analog while others are hard. Same for digital. By trying to do them both ways you will start to get a feel for the pros and cons of analog and digital techniques.

You will probably also destroy a few LEDs, resistors, transistors, and ICs along the way. Their sacrifice will not be in vain as you will probably learn more from the things that went wrong than you will from the things that went right.
 

Thread Starter

sudointellectual

Joined Sep 28, 2013
5
I've found digital led blinking (used both arduino and atmel) very easy. Everything is done via software. But digital is a lot more intimidating, I just get this "where to begin?" feeling. Like, what kind of equipment will I even need? Do you need a function generator and a scope to get serious?
 

WBahn

Joined Mar 31, 2012
30,082
arduino and atmel ARE digital. I think you are trying to describe the difference between "programmable logic" and "pure digital logic".

If you want to start playing around with pure digital logic, one good place to start (even though it is not "pure" digital) is with the 555 timer IC. Get familiar with using it in both of its basic modes -- as a one-shot (monostable multivibrator) and as an oscillator (astable multivibrator). This will be useful for providing a simple low-frequency clock signal for your digital circuitry.

The 555 can act as your function generator for quite a while. Having an oscilloscope is very handy and there are lots of things that will be difficult to do (or do well) without one. But you can get by for quite some time without one when you are starting out.
 
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#12

Joined Nov 30, 2010
18,224
Agreed, but...my best 3 tools are a DVM, a signal generator, and a 'scope. You can do amazing things with only those 3 instruments.

I also count a clamp style amp meter as among my most important tools, but you don't need one for anything less than 10 amps. The DVM will cover anything up to 10 amps.
 

crutschow

Joined Mar 14, 2008
34,470
Also a good way to get a feel for analog circuits is with an analog simulator such as LTspice (free from Linear Technology). It has a somewhat steep learning curve but it allows you to readily experiment with circuits such as active filters and other various op amp and analog circuits to see their operation. Of course you should still build some of those circuits to see how they work in the real world.

LTspice includes a large number of example circuits to get you started.
 

Thread Starter

sudointellectual

Joined Sep 28, 2013
5
Yeah sorry, I meant to say "analog seems intimidating" in my 2nd post, not digital...

I was considering actually making a poor mans digital oscilloscope/function generator as a fun first project, using a USB connected Arduino and controlling the input/output from a graphical interface on my computer. Obviously, I understand that such a scope will be inferior to a real one, but I was hoping I could do enough cool stuff with it to make it worthwhile. Plus it sounds fun.

What do you guys think?
 

ScottWang

Joined Aug 23, 2012
7,409
You can learn something from here.
And do the experiments in the real world, such as NE555 astable, monostable, bjt astable, the op amp waveform generator, the basic bjt on/off control, the basic mosfet on/off control, RC Differential circuit, Integration circuit, using O'scope to see the waveform changing from input and output.
 

Thread Starter

sudointellectual

Joined Sep 28, 2013
5
You already have a scope by way of the mic or line input on your PC.
Never considered that, but I'm not sure what you're saying. Are you saying it's a legitimate viable option for someone just starting out, or are you saying an Arduino-powered discrete USB scope would be useless?
 

WBahn

Joined Mar 31, 2012
30,082
Making a simple oscope using an Arduino is a good project that you should find useful. But it is a bit ambitious as a first project. But not by too much. So break it down into functional pieces that are much simpler and tackle each one of those in turn. Then bring them all together into your scope.
 

WBahn

Joined Mar 31, 2012
30,082
Never considered that, but I'm not sure what you're saying. Are you saying it's a legitimate viable option for someone just starting out, or are you saying an Arduino-powered discrete USB scope would be useless?
What he's refering to is that your sound card offers a way to get a free oscilloscope just by installing some software, such as WinScope. It's a very limited capability scope as your sound card only has a response of roughly 20Hz to 20kHz, so you are limited to audio frequencies and, most notably, can't look at DC signals. That last one is a pretty major limitation. But it's free and it will give you some useful capabilities right out of the box (or right out of the download, as the case may be). You do, however, have to be careful about the signals you put into your mic input as you can easily damage your sound card and/or computer if you aren't careful. But there are simple circuits you can build that will protect your hardware.

An Arduino-powered scope will be quite useful, but it is not something you are going to have working by tomorrow night.
 
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