2

I know what the individual electrical components do (RLC). However, how can I learn to read schematics to determine what the circuit is doing? I have seen some experienced engineers looking at schematics at a glance and figuring out what the circuit does. How do I do this without having to simulate the circuit in PSpice? Are there any tutorials or does this just come with experience?

Null
  • 7,448
  • 17
  • 36
  • 48
user33905
  • 21
  • 1
  • 6
    The first thing you have to do is to stop simulating the circuit in Spice and *think* about it instead. The detailed numbers aren't anywhere near as important as the overall operation. Learn to see the voltages pushing and the currents flowing. – Olin Lathrop Dec 09 '13 at 23:11
  • Thanks, I will review this in detail and ask a follow-up question if necessary. – user33905 Dec 09 '13 at 23:18
  • Read them. Read them again. And again. Understand what the components do, how things work together. Look at many relatively simple circuits and see what they do and how they work and why. After a while you begin to be able to "just do it" except where people have done tricky or very complex or wrong things that don't really work. [Q:How does that work? A: It doesn't! :-) ]. – Russell McMahon Dec 10 '13 at 00:29
  • 1
    Visualize the currents. I like to wave my hands (only when nobody sees) in the way I think voltages or currents behave. Learn to recognize common subcircuits, even when they're drawn different from what you normally expect. And of course memorize common subcircuits like current sources, current mirrors, flip flops, ... Last but not least read articles that discuss how a particular circuit works, eg. from magazines. Once you think you understand how the circuit works you can consider verifying it by running it in a simulator. Reading circuit comes with lots practice. – jippie Dec 10 '13 at 08:11

2 Answers2

3
  • Make your own schematics. There is a certain graphical conventions for making schematics with guidelines such as "inputs towards the left of the page, output towards the right of the page, typically". We have a white paper on that here.
  • Read lots of application notes. After a while, you'll start recognizing blocks, themes, patterns. Apply the patterns to your own schematics, when there is an opportunity.
  • Have your schematics reviewed, when it's possible.
Community
  • 1
Nick Alexeev
  • 37,739
  • 17
  • 97
  • 230
2

If you get a book like "The Art of Electronics" you'll get to know the basic building blocks like amplifiers, filters etc. This takes time and experience. Obviously the type of equipment determines what sort of building blocks you'd see. For example: A guitar amplifier - you'd see things like amplifier stages, filters and automatic gain controls. In a two way radio you'd see things like rf amps, mixers, plls, oscillators. A digital circuit would have logic gate symbols. Standard collections of these gate symbols might be a flip/flop or decoder. As the response above says, you get to know the building blocks and patterns.

Rusty
  • 21
  • 1