[Cr3aTor]

I found circuits and electronics very fascinating stuff because there is so much to it: from customizing other hardware, to robotics, to creating your own devices.
There are also a lot of security related stuff you can do with this knowledge and I would love to learn it. So, my question is this: Is here somebody who is pretty experienced or have any good resources/guidance to help me out? I don't want you to spoonfeed  me. I just want some guidance to know where to start. Some examples could be: I need to firstly understand the physics behind all of this stuff ?  I need to start with arduino? I need to start by playing around with PLCs in order to understand schematics like this?
Any resources, advice and guidance will be much appreciated ! I also think it will help other folks who want to learn this in the future.

[mothered]

@phyrrus9 will certainly find this of Interest. He Is a master of electronics.

Perhaps he may provide some valuable feedback.

[Oni]

@phyrrus9 will certainly find this of Interest. He Is a master of electronics.

Perhaps he may provide some valuable feedback.

I also recommend checking some of his past threads, as they may be of utility to you. He's often in the Discord, if you want to drop by.

[phyrrus9]

I just want some guidance to know where to start. Some examples could be: I need to firstly understand the physics behind all of this stuff ?  I need to start with arduino? I need to start by playing around with PLCs in order to understand schematics like this?

Understanding the laws are a good start, but you don't need to know the physics behind everything. Try to stay away from the buzz words like arduino and logic controllers, these really aren't electronics projects as much as they are programming ones. PLCs are usually fixed hardware devices that you'd use for automating tasks and arduino boards are most commonly used as digital signal processors.

As for that schematic, it's not all that useful for understanding what's going on. That's a manual schematic, meaning that it's intended to instruct you how to replace parts rather than how to understand what's going on. Looking at each of the components, you'll see some identifiers. Looking at the first left upper triangle (being vague to make you look it up on your own), we can see a few labels:

Code:

CMP - input signal +3V3 - reference signal (will be connected to a bus line) U1A - this number will be printed on the board where the component goes LM385D - the part number that goes on the board. Googling it, it's an operational amplifier with a zener diode in a certain configuration, used to provide a linear power voltage 1, 2, 3 - these are the pin numbers of the chip. It's likely a DIP-4 packaging.

Hope this helps you. Of course, analog circuits like this will give you a rough time, but it is possible to learn them early. I advise reading some of the electronics tutorials (link in my signature).