Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Recycle a microwave, BUILD A HIGH CURRENT 12 VOLT SOURCE

  1. #1
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361

    Recycle a microwave, BUILD A HIGH CURRENT 12 VOLT SOURCE

    Recycle a microwave, BUILD A HIGH CURRENT 12 VOLT SOURCE


    Thanks Stu for the idea, here is some info on my BRUTE FORCE POWER SUPPLY

    1.5 VOLTS TO 15 VOLTS OUT AT OVER A 100 AMPS OF POWER, fully adjustable by a slide switch, of a special dimmer switch

    Here is Stu’s video of his supply

    IF YOU DON'T KNOW ANYTHING ABOUT THIS, DON'T EVEN THINK TO DO IT, OR USE ONE



  2. #2
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    I built this from a old used microwave oven the first thing I did was open it up and found the Capacitor and the MOT (the transformer) it’s always near were the power cord comes into the oven.

    THE FIRST THING TO DO IS SHORT OUT THE BIG CAPACITOR



    DANGER THIS WILL KILL YOU IF YOU DON'T DISCHARGE IT



    Discharging a high voltage capacitor

    Discharging your microwave's capacitor is absolutely essential in preventing injury to your microwave, your tools, and

    yourself. A capacitor stores large amounts of electricity even when your microwave is unplugged, and it must be discharged

    A capacitor is discharged by creating a short circuit between each of the two capacitor terminals, and between each

    terminal and the chassis. The chassis is the metal mounting (bare metal surface) of the capacitor. With your microwave unit

    unplugged, touch the blade of a well insulated screwdriver to one terminal. Gently slide the screwdriver forward until it

    reaches the other terminal, holding it there for a few seconds. Be aware that this often results in a loud and startling 'POP'.

    Repeat this procedure in order to create a short circuit between each capacitor terminal and the chassis (bare metal

    mounting plate surface). This same method can be applied to a capacitor having three, and not two, terminals.

  3. #3
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    Next pull out the MOT the oven should be a 1000 watt oven or a very old microwave the bigger the MOT THE BETTER it is

    I destroyed three MOT’s before I got my first one to work


    Here is a pic from another site of a MOT with part of its secondary cut off


  4. #4
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    I got that MOT pic from this site I THINK THEY ARE NUTS BUT HERE IS THE SITE I FOUND IT ON

    http://tesladownunder.com/






  5. #5
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    My MOT with a new secondary made from #8 wire







  6. #6
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    I added my 300 amp diodes and there in a bridge ckt. with a 4000ufd cap to clean up the AC on the DC


  7. #7
    Join Date
    Aug 2008
    Location
    UK....Devon
    Posts
    92
    on a side note here

    i would wind the secondary with transformer winding wire, not pvc or braided insulated cable as the transformer will run so hot it will melt pvc insulation,

    i have been there and wound my own and the iorn core itself gets real hot
    so dont touch it

    i have run my transformer from a 230v supply outputting 75amps easy @ 13.8v

    but be aware if you have no way of adjusting the voltage the voltage will raise with no load connected and fall with heavy current drains so take this in to account when calculating the turns ratio for the secondary

  8. #8
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    Quote Originally Posted by cully View Post
    on a side note here

    i would wind the secondary with transformer winding wire, not pvc or braided insulated cable as the transformer will run so hot it will melt pvc insulation,

    i have been there and wound my own and the iorn core itself gets real hot
    so dont touch it

    i have run my transformer from a 230v supply outputting 75amps easy @ 13.8v

    but be aware if you have no way of adjusting the voltage the voltage will raise with no load connected and fall with heavy current drains so take this in to account when calculating the turns ratio for the secondary
    I'm using a magnetic low-voltage slide dimmer on one side of the primary it's rated @ 1000VA that is how I’m adjusting the voltage here is a link for the dimmer.

    http://www.twacomm.com/catalog/Levit...5C58B00A76A100

    I'm using #8 wire air craft wire plus a fan if i need it there free from the M.O. the MOT is from a 1000 watt unit I have about 20 MOTs here and only about a 1/3 are 1000 watt but I found a source to buy them brand new for a good price

    I also have a 3000 foot roll of #10 wire Teflon coated for the military

    What diodes did you use?

    Gary

  9. #9
    Join Date
    Aug 2008
    Location
    UK....Devon
    Posts
    92


    well heres my transformer it has twin secondaries each 4mm solid core
    each winding has its own 36MB100A bridge rectifier which is cooled by a computer chip heatsink and fan
    the output is connected via the terminals at the top



    when i wound the secondary i measured the voltage after each wire turn till i got the desired voltage i set the voltage high about 15volts so under load it measured a voltage of around 14v
    but if you are running a variable primary you will only need to set the voltage to a high range as the variable primary should be able to compensate


    good luck

  10. #10
    Join Date
    Mar 2009
    Location
    CT
    Posts
    361
    I don't plan on keeping my diodes near the xformer what is your bridge metal or plastic case what is the current rating?

    I will try your dual secondary you may have a good idea worth a try

    thanks Gary

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •