Royer Oscillators vs Regular oscillators, whats the difference?

Discussion in 'General Electronics Chat' started by zero_coke, Nov 13, 2012.

  1. zero_coke

    Thread Starter Active Member

    Apr 22, 2009
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    I'm making some wireless power transfer scheme and I'm at a stage where yeah I'm stuck. I need to feed 8 Amps into my primary coil to set up some strong magnetic field, but to get 8 Amps there I gotta go through a few stages right?

    Right now, I made a power supply to give me 12V @ 10 A from my wall outlet. Then I used the 12V, down regulated it to 5V, and this feeds into my oscillator. This oscillator is some generic oscillator that spits out a signal of some frequency but it has very low output like in the order of milliAmps and roughly 4V. Then I connected this to my power amplifier circuitry but this is where the problem lies. The components to amplify this signal are so expensive...the RF power rated transistor is some $150! I need the transistors to amplify my signal from milliAmps to 8 Amps!

    The real question is: Is this why a Royer oscillator is used instead having a low-power oscillator connected to an RF amplifier? Because the RF amplifier part is too expensive to make? And because the Royer oscillator oscillates at high power??
     
  2. Dodgydave

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    Jun 22, 2012
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    It has the advantages of simplicity,self oscillation, low component count, rectangle waveforms and easy transformer isolation.
     
  3. Audioguru

    New Member

    Dec 20, 2007
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    A Royer oscillator was used a long time ago to make a mains frequency (50Hz or 60Hz)DC to AC power inverter. Since you did not post your schematic then we don't know why yours has an output of only a few mA.

    An inverter made with a Royer oscillator never had a power amplifier.
    A Royer oscillator was never used in an RF circuit.
     
  4. zero_coke

    Thread Starter Active Member

    Apr 22, 2009
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    How do you determine the oscillations and the frequency then?

    I don't understand why a Royer oscillator is used in almost all the projects I see that are doing wireless power transmission for midrange (2-3 feet) distances. Why are they using this instead of a regular oscillator and then pumping the power up? Does the Royer oscillator do that all in one or something?
     
  5. Dodgydave

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    Jun 22, 2012
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  6. Audioguru

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    Dec 20, 2007
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    I have never seen wireless power transmission further than a few inches and higher than a few Watts. Please post the link to the one you are talking about.

    Google shows a few circuits using a low frequency and a low RF frequency but none has a Royer oscillator.
     
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  7. zero_coke

    Thread Starter Active Member

    Apr 22, 2009
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  8. Audioguru

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    Dec 20, 2007
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    Yes, the Pocketmagic circuit has a Royer power oscillator. Its transmitter uses 180W at 63.1kHz and its receiver drives a light bulb with a few Watts a few inches away. VERY poor efficiency.

    The second link needs membership or something to see it. Please post its schematic.
     
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