Transformer driver project, many questions....

Discussion in 'The Projects Forum' started by electronice123, Feb 25, 2012.

  1. electronice123

    Thread Starter Senior Member

    Oct 10, 2008
    I am going to drive an AC adapter xmfr in reverse with a 12V input to get 120V out.

    Primary (low voltage) coil: 54mH, 2 Ohms (Z @ 60Hz=22Ohms)
    Secondary (high voltage) coil: 2.9H, 94 Ohms (Z @ 60Hz=1187 Ohms)

    Calculations at 60Hz: primary current 545mA, secondary current 101mA. The current ratio is not correct since the turns ratio is 1:10. Should I add a primary resistor to limit the primary/secondary current? I want the secondary current to be limited to 20mA when shorted. The load is a very low impedance, about 5 Ohms.

    The driving circuit (5V) is a 555 with a flip flop to make it a 50% duty cycle square wave @ 60Hz...The flip flop inputs to two 4049's to provide enough current to drive the transistor base.....What should the base resistor be? How would I calculate it?

    Thanks in advance everyone!