1. We will be in Read Only mode (no new threads, replies, registration) for several hours as we migrate the forums to upgraded software.

Voltage Conversion Query - Help please!

Reply to Thread

Discussion in 'General Electronics Chat' started by imfaizzi, Oct 11, 2008.

Reply to Thread
  1. Oct 11, 2008 #1
    imfaizzi

    Thread Starter Member

    Oct 11, 2008
    20
    0
    hi

    Let me introduce myself to you. Im a guy who knows-nothing-about-anything in electronics, a newbie to electronics. 0% you can say :). Please help me with my querries.

    I live in Pakistan and here we have 220V power supply to our homes. Our electronics teacher has given us a project to carry out and he has restricted us to use a DC power supply to it (like AA batteries and stuff). He has obliged our projects to be operated on the same power supply on which our home does. Therefore, my question to you is

    How can I convert a 220V power input to 3V or less (while developing my project on a stripboard)?

    Please use more of the simplified english to explain the answer and also do guide me if I've posted this thread in a wrong discussion.:D

    Thank you.
     
    #1 Reply
  2. Oct 11, 2008 #2
    hgmjr

    Retired Moderator

    Jan 28, 2005
    9,029
    219
    Are you required to design the power supply or can you purchase the supply?

    hgmjr
     
    #2 Reply
  3. Oct 11, 2008 #3
    imfaizzi

    Thread Starter Member

    Oct 11, 2008
    20
    0
    yes, we are required to design it. What is the procedure to build such a power supply?
     
    #3 Reply
  4. Oct 11, 2008 #4
    hgmjr

    Retired Moderator

    Jan 28, 2005
    9,029
    219
    Use google to find tutorials on designing power supplies.

    Here is just one example of just such an article.

    hgmjr
     
    #4 Reply
  5. Oct 11, 2008 #5
    imfaizzi

    Thread Starter Member

    Oct 11, 2008
    20
    0
    Your example was pretty much closer to the topics we've discussed in class. But can u describe (in plain english) as how to put together these components to work (as you see it)?

    Im googling though. Lets see what comes as result?
     
    Last edited: Oct 11, 2008
    #5 Reply
  6. Oct 11, 2008 #6
    scubasteve_911

    AAC Fanatic!

    Dec 27, 2007
    1,202
    1
    I'm puzzled why a man teaching elementary electronics is exposing students to lethal voltages? Are there too many students in the class or something?
     
    #6 Reply
  7. Oct 11, 2008 #7
    Wendy

    Moderator

    Mar 24, 2008
    21,838
    3,047
    The first component you need is a transformer, it dictates the rest. How are the component sources in that region? Will he allow you to get a wall wart (an unregulated power supply that plugs directly into the wall outlet) and then build a regulator?

    For what it's worth, they didn't have wall warts when I was a kid, I pretty much had to build everything related to power supplies in the project. Maybe it has influenced my thinking, but I don't see it as a big deal (high school stuff) as long as you pay attention and follow safety guidelines (example, a fuse is a must!).

    If wall warts aren't acceptable, then you'll need an enclosure. You will want to surround the power supply so there are no exposed wires, like Steve said, these are lethal voltages.

    Check out the All About Circuits for building techniques. You can make enclosure out of wood and use terminal strips for most of it.

    Given you're lack of experience I do suggest the wall wart route, you can build a regulator (which is the important part).
     
    Last edited: Oct 11, 2008
    #7 Reply
  8. Oct 11, 2008 #8
    imfaizzi

    Thread Starter Member

    Oct 11, 2008
    20
    0

    Well for that, I must say, he has taken steps already. You see, the whole lab has been supplied with power coming from some kindda transformer (step up or step down that I don't remember right now but it does). He has guaranteed our safety.
     
    #8 Reply
  9. Oct 11, 2008 #9
    Wendy

    Moderator

    Mar 24, 2008
    21,838
    3,047
    That was particularly important information. We need details in order to help. It would have to be step down, basically we need the AC voltage you will be working with.

    http://www.allaboutcircuits.com/vol_2/chpt_9/index.html

    http://www.allaboutcircuits.com/vol_3/chpt_3/4.html

    Note to moderators: This is shaping up as homework from what I'm reading.
     
    #9 Reply
  10. Oct 11, 2008 #10
    imfaizzi

    Thread Starter Member

    Oct 11, 2008
    20
    0
    Yeah, we usually use 3V wall warts (We call it "adapters") but, unfortunately, they're forbidden.

    Its been only 3 months eversince been exposed to electronics course and guess what?? Im so screwed in it. I never had the brains for it. Although, my concepts are pretty much clear about logics , gates & adders etc but the only thing that pisses me off is implementing them. I guess you'll get the picture.
     
    #10 Reply
  11. Oct 11, 2008 #11
    Wendy

    Moderator

    Mar 24, 2008
    21,838
    3,047
    OK, back to basics though, what is the stepped down voltage you have to work with? I assume 50 Hz, since I don't have a clue what Pakistan standards are.

    So before anyone can help, we need the following.

    What is the AC voltage you have to work with? We've got contradictory answers on that one. If you have to start with 220VAC then it isn't safe, but it is doable.

    How much output current and voltage do you need?

    What kind of parts access do you have?
     
    #11 Reply
  12. Oct 18, 2008 #12
    imfaizzi

    Thread Starter Member

    Oct 11, 2008
    20
    0
    The circuit operates on 3V and What I've available is 220VAC. Im using a stepped down transformer of 12V and its doing well. I've designed my power supply for 5V (using 7805).

    Will a 5V power supply enable a 3V circuit of electrical bell?? :confused:
     
    #12 Reply
  13. Oct 18, 2008 #13
    beenthere

    Retired Moderator

    Apr 20, 2004
    15,808
    295
    Yes, but it may cause a failure over time. You can place two diodes in series with the bell to drop an additional 1.4 volts. If the bell current is below 50 ma, you can use something like 1N914's. Higher than that will need a larger diode type, like the 1N4000. It's a kludge, but quite inexpensive.
     
    #13 Reply
Loading...
Related Forum Posts:
  1. PRASS

    HELP PLEASE, amplification or conversion ?

    Posted by PRASS in forum: Power Electronics
    Replies:
    2
    Views:
    191
  2. lmozoz1

    Voltage Conversion query for USA to Australia & back to USA

    Posted by lmozoz1 in forum: Power Electronics
    Replies:
    14
    Views:
    805
  3. evengravy

    help with voltage conversion

    Posted by evengravy in forum: The Projects Forum
    Replies:
    6
    Views:
    1,272
  4. jean28

    Help with this voltage conversion?

    Posted by jean28 in forum: General Electronics Chat
    Replies:
    4
    Views:
    1,008
  5. peterBC

    voltage comparator help please

    Posted by peterBC in forum: The Projects Forum
    Replies:
    2
    Views:
    1,015
You May Also Like:

  1. Insight into the Results of DFT Analysis in Digital Signal Processing

  2. Is It Possible to Be Truly Wireless? Huawei Implements Dialog Semi SoC in Wireless Headphones

  3. Measure Currents of Up to 50, 150, 400 Amps: A Galvanically Isolated Current Sensor IC


Load More Articles