Electronics > Beginners

Where to find beginner projects

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Zero999:

--- Quote from: alex.martinez on February 11, 2019, 09:11:07 am ---
--- Quote from: lieinking on February 10, 2019, 09:48:20 pm ---I've been sick so I'm not working. I decided to do this as a hobby and am learning mainly from allaboutcircuits.com. My problem is I can't find beginner projects easy enough for me. I've mad a simple circuit with an LED but the next simplest circuit I found is a flashing LED which uses a 555 timer. There's no explanation other than a schematic. Every other online project I see is more difficult. I'm looking for projects that walk you through holding your hand. Where Can I find the simplest projects with good guidance?

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555 timers are relatively easy if you understand how the IC works internally (and this why it is called 555 timer). Here you have an explanatory video about the 555 timer.
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In my opinion the 555 is not a very beginner friendly IC. It's good in that it's easy to grasp the internal workings. The main downside is it has the nasty habit of drawing large current spikes from the power supply. Proper supply decoupling is mandatory. Careful attention should also be paid to the  layout, with the decoupling capacitor near to pins 1 and 8 and the time delay capacitor as close to pin 7 as possible. A common beginner error is just slapping it on a breadboard and expecting it to work.

The CMOS versions such as the ICM7555, TS555 and TLC555 are much more forgiving than the old NE555 and SE555. They do have their disadvantages, compared to the traditional 555: more ESD sensitive and weaker output stage, but that's more than made up for by the advantages: wider supply voltage range (2V to 18V, rather than 4.5V to 16V), lower bias currents & higher input impedance, therefore capable of using larger timing resistors and longer delays, lower power consumption, faster and more stable: supply decoupling and layout are less critical. There's also the TLC551 which can work down to 1V and is handy for single AA cell projects.

Another beginner error is using large capacitors and resistors for the 555 timer, which leads to unpredictable delays and instability. The 555 is only really suitable for short delays under a couple of minutes or so, even the CMOS variants. The talk about hours on the data sheets is nonsense and pure marketing bull. For longer delays and lower frequencies, there are counter + oscillator ICs available, such as the CD4536, CD4541 and ICM7242: best monostables or the CD4060B and CD4521B: more suited to astables. They also have a wider power supply voltage and lower power consumption, than even most CMOS 555s. The only downside is they have a wimpy output, but it's easy to add a transistor to boost it.

Mechatrommer:

--- Quote from: lieinking on February 10, 2019, 09:48:20 pm ---I've mad a simple circuit with an LED but the next simplest circuit I found is a flashing LED which uses a 555 timer. There's no explanation other than a schematic. Every other online project I see is more difficult. I'm looking for projects that walk you through holding your hand. Where Can I find the simplest projects with good guidance?

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refer to 555 datasheet to see what it does, and what other things around it do. you'll understand by going back (or down) further to simpler and simper thing... ymmv.

james_s:
You can go quite a long way into electronics without any heavy duty math. If you want to be a professional EE there is no getting around the math, but in my hobbies I rarely need anything beyond basic algebra. Learn Ohms law because you will use that all the time, but beyond that if it's just a hobby, focus on the practical side of things. As with programming there is a bit of a learning curve to get to where things start to get interesting.

dnwheeler:
The books "Make: Electronics" and "Make: More Electronics" by Charles Platt progress nicely from very simple concepts and experiments to more advanced projects. There are also component kits available with all parts needed for the experiments and projects.

rstofer:
I ordered a copy of Forrest Mims; "Getting Started in Electronics" and it's a really good book.  It covers all the usual topics like the nature of electricity, current flow, voltage and so on.  I really wish it didn't describe current in terms of electron flow (pages 20 & 47) but that's just a preference.  I understand why it was done but these days we have pretty well settled on 'current' flowing from + to -.  Maybe it is confusing, maybe not...

There is also a nod to analog computing on page 94 so that's pretty nice.  It is the one topic regarding op amps that interests me.

There are a lot of interesting circuits to build, something for everyone.  For the beginner, it is much more approachable than "Learning the Art of Electronics" (in my opinion).  I think I am pretty comfortable recommending the book for the absolute beginner.  They will get from it in some proportion to how much time they spend reading the material and doing the experiments.

https://www.amazon.com/gp/product/0945053282

As to the experiments, what to do about parts?  Each experiment is using something different, op amps, logic gates, resistors, transistors, capacitors, etc.  What beginner is going to have this stuff laying around?  Maybe the student should batch together a bunch of interesting projects and buy the components in a single order.  And order some of the components, like resistors and capacitors, perhaps transistors, in multiples of 100.

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