No power required? Does that mean free energy?!? What do you mean by that?

 

No power required? Does that mean free energy?!? What do you mean by that?

Let Google be your friend, and it will take you here; enjoy.

I had one as an 8-year-old; it was my first project, with my Dad providing guidance. Very educational.

 

Oh, I think now I understand what you mean.

 

Na you cant say a crystal radio is free energy some one had to pay for the radio station.
I sure that was nowhere free LOLOL.

I Can remember them days I pulled maybe 200 feet of copper wire to tree and hooked the crystal radio ant to that I made the diode the coil
hooked the ground to a pipe.

I then found a amp in a tube radio that didn't work took the amp out and took the tuning cap too
walked to the drugstore to test tubes found a bad one they even had parts at the drug store.

It worked I could tune 3 stations and play them out a speaker It was fun back then.

 

Both

You didn't mention your education.

Learn as much as you can from formal education. Study circuits and strive to understand what each component does and how the values were selected. Read everything you can find about circuits; vendor application notes/manuals are good sources of information.

 

No shortcuts. Just shorts. Lots and lots of shorts.

yup... even with a perfect gpa (not that i had one...not even close), you learn the best by just doing and making mistakes.

 

How to be a good circuit designer?
What is the shortest path, to know how to analyze circuits or to design them? Or either one will lead to the other?

Get electronic magazines subscribed, Eti , Practical Electronics, or electronic books like Elektor 300 series, build stuff from them that you can use, like signal generator, psus, etc, these magazines have description of the circuits explaind, no substitute for getting plenty of circuits and studying them.

 

No shortcuts. Just shorts. Lots and lots of shorts.

Ha Ha!

 

Get electronic magazines subscribed, Eti , Practical Electronics, or electronic books like Elektor 300 seies, build stuff from them that you can use, like signal generator, psus, etc, these magazines have description of the circuits explaind, no substitute for getting plenty of circuits and studying them.

Electronics magazines such as Popular Electronics, Practical Wireless, Practical Electronics used to be a great source of design, construction, and technical information. I couldn't wait for the my next month's issue of Practical Wireless to arrive in the mail. Then I would devour it from cover to cover at least four times over before the next issue arrives.

I don't know if the magazines today are good as they used to be.

 

I design a circuit so that it works with parts that have minimum spec's or have maximum spec's or tolerance. Then every circuit made with passing parts works perfectly. Some people design a circuit with only "typical" spec's or on a simulator then circuits made with minimum or maximum spec's or tolerance do not work. When you buy parts maybe the last production run was mostly minimum or maximum spec's with hardly any typical ones.

 

I design a circuit so that it works with parts that have minimum spec's or have maximum spec's or tolerance. Then every circuit made with passing parts works perfectly. Some people design a circuit with only "typical" spec's or on a simulator then circuits made with minimum or maximum spec's or tolerance do not work. When you buy parts maybe the last production run was mostly minimum or maximum spec's with hardly any typical ones.

Yes. Very true. When it says "100uf+-50" do not treat it as just a 100uf cap (or whatever)! If you do that, you will encounter many problems, and long story short...

 

Yes. Very true. When it says "100uf+-50" do not treat it as just a 100uf cap (or whatever)! If you do that, you will encounter many problems, and long story short...

What, "100uf+-50" ?! .... is there such thing?! hehehehe

 

High capacitance electrolytic capacitors have high tolerances, 20% for example.
Don't be surprised to find a brand new 100μF reading as much as 120μF.
You design with the fact that ±20% variation in actual value makes no difference to the performance of your circuit.

 

High capacitance electrolytic capacitors have high tolerances, 20% for example.
Don't be surprised to find a brand new 100μF reading as much as 120μF.
You design with the fact that ±20% variation in actual value makes no difference to the performance of your circuit.

Interesting!

 

Here is something they don't teach you in electronics class.

It is common practice to put two or three decoupling capacitors in parallel across the supply and ground pins on an IC.
These could be a 0.01μF, 0.1μF and 1μF capacitors.
Theory of capacitances in parallel tells you that they add. Hence the net capacitance is 1.11μF.
However a 1μF cap with 20% tolerance negates having the additional lower value capacitors.

What gives?

Where do you learn stuff like this except right here on AAC?

 

Here is something they don't teach you in electronics class.

It is common practice to put two or three decoupling capacitors in parallel across the supply and ground pins on an IC.
These could be a 0.01μF, 0.1μF and 1μF capacitors.
Theory of capacitances in parallel tells you that they add. Hence the net capacitance is 1.11μF.
However a 1μF cap with 20% tolerance negates having the additional lower value capacitors.

What gives?

Where do you learn stuff like this except right here on AAC?

Cool

 

What, "100uf+-50" ?! .... is there such thing?! hehehehe

I've bought some supercaps that were like "500F +80% -20%".

 

I've bought some supercaps that were like "500F +80% -20%".

hmmm thats an important thing to think of from now on...

 

hmmm thats an important thing to think of from now on...

It's important to remember that ALL electronic components have tolerances-- that is, there is always some uncertainty as to the exact value of any given physical component in a circuit, and its actual value can be anywhere in the range specified for its tolerance. Circuits must be designed with this variability in mind.

 

Also its imortant to remember that virtually all components have temperature dependence, so when you start designing something that needs to work at any other place than your bench you really have to keep that in mind.