I have a question about this site.

Discussion in 'General Electronics Chat' started by thedarkknight782, Sep 19, 2009.

  1. thedarkknight782

    Thread Starter New Member

    Sep 19, 2009
    6
    0
    I am a beginning electronics person and I have heard that the ebook on this site is a good one. I am also interested in seeking assistance on the forums. However, building circuits had the potential to be a dangerous activity. How can I be assured that I am not being told bad information? What type of questions should I ask myself/things should I look for when determining this?

    Are there any ways to learn this sort of thing elsewhere (not the head knowledge but the experience)? I live near a university but don't know if I could do anything there.

    Thanks.
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,647
    2,346
    Hello,

    You will not have to worry to get bad advice over here.
    There is a group of experienced people on this forum.
    They will also let you know when things get dangerous.
    Otherwise the good team of moderators will tell you.
    The topics used in this forum is quite broad.
    You can always use the search funtion to see how some topics have developed.

    Greetings,
    Bertus
     
  3. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    The danger in electronics is in the handling of the higher voltages. You can feel safe when handling low DC voltages.

    As for the accuracy of the information provided in this and other electronic forums, other members will often make corrections to information that is in error.

    hgmjr
     
  4. thedarkknight782

    Thread Starter New Member

    Sep 19, 2009
    6
    0
    Well, in addition to high voltages (which I may have projects that use later, just not now) you have to worry about capacitors and also messing up electronic components (some of them aren't cheap). Regardless, I just wanted to make sure good, accurate information would be given on the site as well as the ebook. Is electrical safety described in detail in the ebook as well? Also, if someone else wanted to learn electronics type of stuff what information would I tell them to ensure them the site was accurate? Do any of the moderators have electrical engineering degrees or anything like that? Thanks.
     
  5. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    I think you will find that a significant percentage of the members have engineering degrees and many of those that do not have a degree are endowed with many years of hands-on experience. Neither of these criteria are required for a member to offer advice on a topic. This is a free-form information exchange so all are encouraged to share their knowledge. If the information is inaccurate, someone will most likely come along and clarify the advice.

    hgmjr
     
  6. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    The AAC book has an excellent experiments section for beginners. Our book teaches both theory and hands on. While no one like to mess up, it happens. Many of our protoboards (an almost necessary requirement for cheap experimentation) have scars from being melted. Not that mine do. :rolleyes: I've been doing this long enough I've thrown away the evidence. ;)
     
  7. ELECTRONERD

    Senior Member

    May 26, 2009
    1,146
    16
    The higher potential stuff is something to be concerned about, but a lot of the theory in the AAC e-book is in regards to lower voltage and current type stuff. One thing you should be aware of is polarity. When building circuits you must note the positive and negative notations on IC's, electrolytic caps, transistors, and other parts. With some components, however, you don't need to heed polarity such as resistors, and ceramic caps.
     
  8. thedarkknight782

    Thread Starter New Member

    Sep 19, 2009
    6
    0
    So you say the theory in the ebook is mainly for low voltage circuits? Do most electronics operate on low voltages like discussed in the ebook or are there some "common" devices/circuits that use a voltage high enough to be cause for concern?

    What would be an example of a high voltage circuit or wiring?
     
  9. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    1,571
    230
    anytime you plug something into the wall, you need to asses that your safety is maintained. ALWAYS make sure that your project is isolated from your household AC potential. This is easiest done by taking power from a common transformer supply.

    Ever stick your tongue on a 9 volt battery terminal? Don't wag your tongue over your constructed circuits.

    Recognize certain circuits/devices that are inherently dangerous, ie; photo flash charging cicuits, laser devices.

    Don't leave powered circuits unattended.

    Use your senses; smell, touch, sight, sound. If something is unexpected, remove power, ie; hissing, hot, smoke.

    I have blown up electrolytic capacitors that behave like firecrackers. Personal protection such as glasses should be considered.

    I'm not an engineer, but I have years of playfull experience that would rival many engineers in practical application. I'm not yet a journeyman electrician, but I've taken a few high potential smacks to double check my layouts before energizing.

    Most of all, from your very first experiment, sit back and ask, why did this do, or not do what I expected? What are the underlying principles that make this such a unique field. Best wishes on your journey
     
  10. ke5nnt

    Active Member

    Mar 1, 2009
    384
    15
    In reply to using your senses when experimenting, that's one piece of advice to live by. When I was a lot younger, and experimenting with electronics for the first time really, I pulled apart a tube-type Television. I heard a hissing noise which I thought was pressurized air escaping from somewhere. What did I do? Well I'll just stick my hand there and figure out where the air is coming from :eek:

    Lightning my friend, human lightning, even got the buddy I was sitting next to. Arched between our elbows. Common sense is a learned skill... I didn't have it yet.

    In the ebook, look for the videos too. Great info there! allaboutcircuits is by far the best online resource for experimenters, hobbyists, etc. My number 1 bookmark.
     
  11. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    1,571
    230
    :confused: :eek:

    Good one, I forgot to mention picture tubes as an inherently dangerous cicuit.
     
  12. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    Perhaps first an example to describe a circuit with high voltage in a hobbyist sense. Sa you build a (low voltage) power supply from scratch. Then you connect one side of the transformer to the mains. Doing this for a beginner is not recommended. It is a lot of potential hazards. But on the transformer output the voltage is safer. But then i was young and tried to build a power supply. I nearly lost my eye to an exploding lm723 chip. so it is not total safe;)
    So to the technical terms
    The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define high voltage circuits as those with more than 1000 V for alternating current and at least 1500 V for direct current, and distinguish it from low voltage (50–1000 V AC or 120–1500 V DC) and extra low voltage (<50 V AC or <120 V DC) circuits. This is in the context of building wiring and the safety of electrical apparatus.
    In the United States 2005 National Electrical Code (NEC), high voltage is any voltage over 600 V (article 490.2). British Standard BS 7671:2008 defines high voltage as any voltage difference between conductors that is higher than 1000 V AC or 1500 V ripple-free DC, or any voltage difference between a conductor and Earth that is higher than 600 V AC or 900 V ripple-free DC. Electricians may only be licensed for particular voltage classes, in some jurisdictions.[1] For example an electrical license for a specialized sub-trade such as installation of HVAC systems, fire alarm systems, closed circuit television systems may only be authorized to install systems energized up to 30 volts between conductors, and may not be permitted to work on mains-voltage circuits.
    The general public may consider household mains circuits (100–250 V AC), which carry the highest voltages they normally encounter, to be high voltage.
    Voltages over approximately 50 volts can usually cause dangerous amounts of current to flow through a human being touching two points of a circuit, so safety standards generally are more restrictive where the chance of contact with such high voltage circuits exists.
     
  13. bigcape

    Member

    Sep 18, 2009
    158
    0
    Another forum is building a stungun circuit that runs on a 9V battery that could kill a heart patient with one zap
     
  14. loosewire

    AAC Fanatic!

    Apr 25, 2008
    1,584
    435
    Darknight-Take it slow until you read and do small projects.Think about
    logical things first,some of the guys are so far advanced that you have
    to get them to jump in and add to post. Lets try this,a small transistor
    radio suppied by three volts needs no fuse.You am and fm you have a
    basis tuninig and amplfier curcuit.You have a am/fm switch,picture a red
    wire from batteries going to power each separate curcuit.The black wire
    soldered to metal frame as ground. The good thing about a small radio
    you have diode and speaker,tuning capacitor resistor ,coils,capacitors
    you learn about a lot parts. Now someone if they feel nice will draw us
    a small am/fm 3 volts radio diagram,marking the places that red wires go
    to power radio,you get an antenna to,that the way it works.This way
    no one get hurt,you learn.By the way you get an on/off switch.Your radio diagram
    may be waiting for you when you sign on. I've been punching keys forever
    these guys can type this out in 2 minutes. One radio please,thank you guys.
     
    Last edited: Sep 22, 2009
Loading...