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Welcome to electronics design! I've never had electric shocks before, but frying components sure. Don't work with mains voltage directly if it worries you. You

by joshvm 11y ago

Welcome to electronics design! I've never had electric shocks before, but frying components sure. Don't work with mains voltage directly if it worries you. You can power most hobby projects from a USB port or a wall wart. Designing power supplies is one area where you might want to read up on things like trace clearances, but again, look at YouTube for PSU teardowns (bigclivedotcom has plenty). As always it's mostly human error. I have never (literally) fried a component from overheating, it still amazes me how hardy modern ICs are. I've also never paid too much attention to ESD protection, though if my job depended on it then I would. What has happened is shorts, often. Even the GPU guy routed his board with GND and VCC back to front, it happens to the best of us. Most chips are at least partially tolerant to silly things like overvoltage, so even if you accidentally short some GPIOs on a micro, the protection circuitry might save you. Simple advice is to put a low-current polyfuse on every prototype you make. It's saved me so many times when I've shorted power supplies by accident. The more complicated your circuit, the more likely it will be that you mess up. Don't try and solder a 150-pin BGA on your first board. Build some breakout boards for sensors, build your own microcontroller dev board (ARM if you want a challenge) or pick a project from the internet. Odds of messing up you first board in some subtle way? Unless it's a very simple board, > 80%? Components are cheap though, roll with it! Plus you probably won't brick all the components if something goes wrong, the magic smoke will usually only come out of one. When I make mistakes, usually they're footprint (e.g. wrong pinout) or construction errors (shorts between pads, etc). If the schematic is incorrect then that's another issue, but most often it's things like not reading a datasheet properly and forgetting to connect a pin, tying an positive-enable pin to GND rather than VCC, etc. In principle layout engineers assume that the circuit diagram is gospel, so the blame doesn't always lie with them. Of course if you're the designer and the layout engineer... I'm now at a stage where I can get a board back from the fab and it'll usually work :)

akiselev 11y ago
Just to add some: There's a lot of specialization in EE like any other field and you can't really dive into everything. I find power electronics to be more of a black art than RF or high speed digital so I try to never design my own. I've seen people spend years working on a single design for a solar inverter making dozens if not hundreds of iterations, testing with all types of switching circuits and chips, comparing the behavior of one vendor's capacitor to another, understanding different transistor behavior, and so on. Thankfully, nowadays you can go to TI and use their automated schematic generator for your power supplies. They have many reference designs and tons of documentation on PCB layout in a variety of situations. Debugging them, however, is a whole different story. If you can afford it just buy a module and never think of it again. Polyfuses are a godsend, especially if you're designing a high current PCB like a motor controller. It really doesn't take much to melt a 1.5 oz 10 mil trace. How expensive trial and error is depends on your experience. When I'm done with using a board or have some old electronics to throw away, whether I bricked it or its obsolete, I always throw it in a pile. When I have time I just go through and desolder each nontrivial part because it helps build an intuition for how each type of solder will respond to heat and flux, how wick looks as it absorbs solder and how to move it to get all the solder without overheating the chip, and so on. You need to develop that muscle memory like a surgeon would because once you're good enough you can do crazy things like snake a tiny wire under a BGA chip under an xray to fix flaws in the design or reflow. In more expensive designs I'll regularly take small gauge wire and solder it all over to fix the design as well as cut traces or lift copper layers after stripping the FR4. Hand assembling electronics is largely more craft than engineering.

by joshvm 11y ago

akiselev 11y ago

Just to add some: There's a lot of specialization in EE like any other field and you can't really dive into everything. I find power electronics to be more of a black art than RF or high speed digital so I try to never design my own. I've seen people spend years working on a single design for a solar inverter making dozens if not hundreds of iterations, testing with all types of switching circuits and chips, comparing the behavior of one vendor's capacitor to another, understanding different transistor behavior, and so on. Thankfully, nowadays you can go to TI and use their automated schematic generator for your power supplies. They have many reference designs and tons of documentation on PCB layout in a variety of situations. Debugging them, however, is a whole different story. If you can afford it just buy a module and never think of it again. Polyfuses are a godsend, especially if you're designing a high current PCB like a motor controller. It really doesn't take much to melt a 1.5 oz 10 mil trace. How expensive trial and error is depends on your experience. When I'm done with using a board or have some old electronics to throw away, whether I bricked it or its obsolete, I always throw it in a pile. When I have time I just go through and desolder each nontrivial part because it helps build an intuition for how each type of solder will respond to heat and flux, how wick looks as it absorbs solder and how to move it to get all the solder without overheating the chip, and so on. You need to develop that muscle memory like a surgeon would because once you're good enough you can do crazy things like snake a tiny wire under a BGA chip under an xray to fix flaws in the design or reflow. In more expensive designs I'll regularly take small gauge wire and solder it all over to fix the design as well as cut traces or lift copper layers after stripping the FR4. Hand assembling electronics is largely more craft than engineering.