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DC to AC Converter

  1. Apr 11, 2009 #1
    I'm trying to understand the converter in this link:


    I don't see how the two transistors and the DC source cause the curretn to alternate through the windings. It seems that both transistors would be passing current constantly, not alternating between them.
  2. jcsd
  3. Apr 11, 2009 #2
    That's a blocking or a relaxation type of oscillator. It takes advantage of being able to store energy in an inductor, and releasing it. This is a mirror example of I'm not sure if you are familiar, a flip flop oscillator with two transistors and two capacitors.

    Basically, when you turn it on, a rush of current through the collector coil will induce a voltage in the feedback coil that drives the base of the transistor, thus letting more current to run through the collector until it reaches a steady state. When the current reaches steady state, the main coil is no longer inducing voltage in the feedback base coil, thus the transistor begins to turn off. As the current than ran through the main coil collapses, it will induce oppose voltage in the feedback coil, thus turning off the transistor for good. When that reaches steady state, we are back to step one,
  4. Apr 11, 2009 #3

    I've been working with DC and ICs too much. This is the beginning of my journey to better know analog.

    Thanks for the help!

    Also, would increasing the inductance decrease the frequency of the AC?
    Last edited: Apr 11, 2009
  5. Apr 11, 2009 #4
    Yes, because it would take longer for the current to reach a steady state in the coil.
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