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How can you really mess up in amateur electronics?

  1. Mar 4, 2017 #1
    I work with max. 18V DC current, amateur. I thought the max. thing you can do is to mess up your multimeter, but I saw some capacitors exploding pretty big even on 9V on Youtube. As an utter beginner and with no mentor I would like to know about what to avoid to be safe. I am using max: 18Vs, but better safe than sorry right?
    My equipment: multimeter, a breadboard, diodes, capacitors (electrolytic), transistors, thyristors, triacs, LEDs (I destroyed one so far with 9V), resistors, integrated circuit...

    As a bonus you an can also say tips regarding AC (220V here), but the only thing I dared with it was measuring it's 230V with a multimeter, and 50-60 Hz frequency, but I do not plan to experiment much/at all with high voltage.
    Last edited: Mar 4, 2017
  2. jcsd
  3. Mar 4, 2017 #2


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    You don't say what your power source is capable of concerning amperes. We can assume you are using a pair of 9 volt batteries which is reasonably safe. But, we could also assume you are using two automobile batteries one of 6 volts and the other 12 volts. It won't shock you but it could burn your flesh down through to the bone if you get a ring, watch or similar jewelry in the wrong place. Alternatively, if you are using 9 volt batteries, you can put a 1/4 watt 100 ohm resistor across one or both batteries while holding the resistor between your fingers and it will definitely burn you.
  4. Mar 4, 2017 #3


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    18V DC is a voltage, not a current .... 1st misunderstanding :wink:

    stay away from AC mains till you have gained much more experience

    buy a electronics multi-project kit from ebay, amazon ... a local electronics store and start learning ....

    here's one of many examples from ebay ....
    dunno what your budget is ? there are cheaper ones and there are more expensive ones

  5. Mar 4, 2017 #4


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    Can you post a picture of your initial test bench? That will help us to offer up more tips.

    Oh, and always wear your glasses or safety glasses. Caps can blow up at the most unexpected times...
  6. Mar 4, 2017 #5


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    I also wouldn't mind seeing your test bench.
  7. Mar 6, 2017 #6
    Thank you for the answers. As a "test bench" I have an ordinary wooden table with 2 drawers (where also my keyboard lies, since I often consult Youtube to do projects). I always see to clear a huge area on the desk to do an experiment - always huge and clear from other items. However there are also some A4 papers (often beneath the circuit/experiment itself) in that area - to do calculations. Around that area I have things on the table that I work with at the moment (LEDs, resistors, transistors, capacitors, alligator clips, copper wire, multimeter, breadboard, etc.). In a huge wardrobe nearby I have drawers where I store material that is less frequently needed but might come in handy - stored in several shoe boxes, roughly classified - more important things are in airtight bags, other things just thrown inside the boxes (balloons, wire, screws, parts of household things that may come in handy, etc. ). Neodymium magnets are stored in plastic boxes seperately filled with handkerchief to minimize breaking away from metal. From Monday to Friday I will be in another city, but when I return home I can take a picture - after bit of cleaning of course :)
    Last edited: Mar 6, 2017
  8. Mar 6, 2017 #7
    A commitment to safety involves a few things. One is make sure you have appropriate protective gear - e.g. I wear a full-face mask when desoldering components or powering up a circuit with big caps for the first time. And I have large-size safety glasses that go over my reading glasses that I can wear the rest of the time without being too bothered by the extra weight on my face.

    And you can outfit your bench and/or shop against particular dangers - e.g. I set a fan to blow across my bench when soldering so I minimize the fumes I inhale, plus I have added a GFCI outlet at the head of the branch of outlets serving my bench, so if perchance I do something stupid and interpose my body between hot and ground, the mains will shut off faster than relying on a breaker.

    But - the very best way to stay safe is to learn and apply good safety procedures. Most of these are behavioral in nature. All the personal protective gear in the world means nothing if you never wear it, for example. Awhile back on a different forum, to do with folks who enjoy building or modifying electric guitar amplifiers, I posted a list of links for learning about safety in the home electronics workshop. I'm copying & pasting those links below. The vast majority of this advice comes from EEs and professional electronics repair technicians.

    As an example: the comment above by @Averagesupernova about possibly burning a seriously deep hole in your flesh, if you're wearing a ring or other metal jewelry while working on a circuit that can supply not only a hefty voltage but a corresponding current, is completely on target. Thus in the last of these links, from the PDF book on "Solid State Guitar Amplifiers," you'll see a suggestion to remove rings, metal jewelry, etc., before working on anything live. You might think you don't need to apply this particular piece of advice when working on a tiny solid-state circuit powered by a single 9V battery wired up on a breadboard, and you'd be correct; however, my own view is that the way to build safety habits is to practice them from the get-go so that they really do become habits; this seems better than finding excuses not to practice them. But they can never become unthinking habits; you always need to be mindful. Especially with mains or high DC voltage, no matter how many safety procedures you put in place, you will always be vulnerable when working on live exposed circuits; the point is to minimize the risk, in part by awareness that it's always there.

    Here's those links -
    I'd be interested in other links or advice people have to share . . .
    Last edited: Mar 6, 2017
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