I have been working on my Make: Electronics book and a couple circuits and had a thought here .. Does anyone else come up with there own designs that never been done before or just simply copy and mod a circuit to fit your needs ??I am not looking to troll here in anyway but I am simply asking cause with my voltage ref I am taking someone design and modding to work for me.. I just feel bad as I don't have the skills to figure out something on my own..

 

I usually design from scratch, but that doesn't mean it's an original design and doesn't stop me from putting a copyright on my work. There are many ways to implement the same functionality. If I knowingly use something done by someone else, I make it a point to give appropriate attribution.

 

I guess I started in about 1966. By 1977 I could design whatever I need.
Night detector? What do I have? A CdS cell. OK. start from there.
Battery charger? What do I have? A 12 volt 150 watt toroid? OK. Start from there.
A single supply low noise pre-amp? Obviously a j-fet. Start from there.
A metronome? Obviously a 555 timer.
A thermostat? I have some 10k thermistors and some 723 chips. Viola, instant thermostat.
I have arrived at the point where the only thing I look up is datasheets for individual parts.

 

I started like you but I have spent hours diddling with op amps, logic chips of various types, microcontrollers, transistors and so on until I knew how they each worked. The linear stuff is the most challenging (op amps and transistors) but take your time, find some good tutorials and ask for help until you understand.

Also, focus on the basics. There are thousands of different permutations of amplifier with one to dozens of discrete transistors. Break it down and determine what each transistor in each stage does.

Good luck.

 

Much of my professional work has been lunatic fringe -- companies came to us because everyone else told them that what they wanted to do couldn't be done. So most of our core circuits have been very novel and developed from scratch. Even as a hobbyist I've preferred to design from scratch because that's the most rewarding for me. I'm sure I could have dug around and found other circuits that might have worked with a few tweaks and gotten something working quicker, but my first forays down that path, while still an undergraduate, were not too fruitful. I had bought several volumes of The Encyclopedia of Electronic Circuits and tried to use them as a starting point on a few projects. Each resulted in a lot of wasted time before I just started with a clean sheet of paper and worked up something on my own. Now, it could be that that particular publication is of low quality or it might have been that I didn't have enough experience to be able to start from someone else's design and properly tweak it for my needs. But it soured me on that approach in general.

That's not to say that I don't enjoy reading about circuits that do things that I haven't done and studying them to understand how they work -- and of course the knowledge that I walk away with becomes added to my bag of tricks for future use.