How to purchase a transformer!

Discussion in 'General Electronics Chat' started by USNtron75, Nov 26, 2011.

  1. USNtron75

    Thread Starter New Member

    Dec 14, 2010
    I am building a bench power supply (first project). I am having a hard time locating a 120VAC step-down to 12VAC. Whenever I search for a transformer none of them are ever described in such terms. How do I proceed? Thank you.
  2. hobbyist

    AAC Fanatic!

    Aug 10, 2008
    Radio shack sells them regulary, if you want to look them up on the innernet, google " POWER TRANSFORMERS"

    They ususally give the ratings as input and output voltages, with there respective current ratings.
  3. SgtWookie


    Jul 17, 2007
    Instead of building a linear supply, you should consider converting a spare ATX or ATXplus12 form factor PC power supply into a bench supply.

    Google "ATX bench supply" for lots of ideas.

    I converted an old Compaq 250W supply years ago; has +3.3v, ±5v, ±12v. I have a separate linear supply if I need a variable supply, but the converted ATX supply has proven itself to be quite handy.
  4. K7GUH


    Jan 28, 2011
    Converting an ATX supply is a good idea, but I think you would learn more from building a conventional linear power supply: transformer, diode(s), capacitor(s), and a reasonable load resistor. You can consider adding a regulator circuit after the basic unit is working.