PWM power supply

Discussion in 'General Electronics Chat' started by wes, Feb 1, 2010.

  1. wes

    Thread Starter AAC Fanatic!

    Aug 24, 2007
    Hi i am working on a project that will require a PWM (Pulse Width Modulation) power supply.
    The power supply MUST be able to switch on and off at 6 GHZ (6 Billion times a second.) The project has to do with a transformer (air core ). Can't tell much else.

    I know there are device's that can do this but i do not know where to find them. Is there a way i can do it from a micro-controller or something? I have to be able to make the tiniest adjustment's to the pulse (like 10 picoseconds adjustment's ). So not exactly 6 GHZ but really really close.

    If any one knows where to look then that would be awesome.
  2. iulian28ti


    Dec 4, 2009
    Heh.... if you're gonna build such thing (6 GHz.... holy crap !), you're not gonna be able to make it too powerful. Parasitic capacitance and dV/dt limit in MOSFETs (if that is what you wanna use) are gonna give you headaches.

    Tell me, is it about wireless energ transfer ? If so, then you could start by studying the work of intel and others involved in this domain.
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    This is not an everyday breadboard project. Are you sure you are equped to such project.
  4. SgtWookie


    Jul 17, 2007
    Right smack dab in the middle of the C-band spectrum. :eek:

    It's going to be a mighty challenging project.

    When you get up that high in frequency, parasitics are a major consideration. Was working on a 7-pole 4.2GHz LC low-pass filter a few years ago; the inductors were a short piece of wire with a loop about the size of this letter "u", and the capacitors were single-layer ceramics that were custom trimmed to about that same size.

    You might find the MiniCircuits site to be helpful:
  5. wes

    Thread Starter AAC Fanatic!

    Aug 24, 2007
    lol, No it is not an everyday project and I know I am know I am not fully equipped to build what I want to build, lol, Financially and intellectually, lol.

    Thank's for the site link to, it is really helpful.

    BTW i only planned on powering the transformer with about 20 volt's or less and maybe a max load of about 5-10 watt's so no more then 250ma to 500ma on the primary.

    Do any of you or anyone know how far apart i can make the two winding's of the transformer and still be able to get at least 25% to 50% power transfer.
    i need them to be at the least 2 inches apart but could i make maybe 4 inches apart or even 5 inches. If i can space them 4 inches apart and still get at least 25% power transfer, then I can drop the frequency down to just 3 Ghz (the speed of my old pentium 4, lol ) and at 5 inches i can drop it to just 2.4 Ghz!

    where can i figure out how to calculate how much power i can transfer to the secondary and the losses that would occur due to the distance between them?
  6. lmartinez

    Active Member

    Mar 8, 2009
  7. 3ldon

    Active Member

    Jan 9, 2010
    might be cheaper to send the energy over a laser with the latest 25% efficient solar cells (for a specific wavelength)
    You might as well just us a 2.45Ghz magnetron and a Rectenna
  8. wes

    Thread Starter AAC Fanatic!

    Aug 24, 2007
    Unfortunately I can not use a laser. It has to be a transformer Because of the way they work. I have to use a magnetic field, I can't use light even though from what I have read on quantum mechanics, that the force carriers of the magnetic field are photons(actually they call it virtual photon's). The whole project relies on pulsing power.

    I do have a question on magnetic fields though.

    is it possible to turn say coil a on and shut it off before the magnetic field produced from coil a reaches coil B but not to soon so as the magnetic field would be shut off before it even arrives and induces a voltage

    So basicaly
    1. turn coil a on
    2. turn coil a off before magnetic field reaches coil b
  9. wes

    Thread Starter AAC Fanatic!

    Aug 24, 2007
    I think it is possible because the information that coil a is now off and that the magnetic field stop's propogating outward's to it outer most point could not reach the outermost point of the magnetic field before it reaches coil b and by the time it reaches it the magnetic field would have induced a certain voltage.

    if it did reach it then wouldn't that violate the whole nothing goes faster then light law?