• Re: dc/dc converter ckt

    From John S@21:1/5 to John Larkin on Thu May 26 20:08:25 2022
    On 5/26/2022 7:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1

    Oh. So you don't want to buy one or need help. You just feel compelled
    to tell us about it, right?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to All on Thu May 26 17:16:56 2022
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1



    --

    If a man will begin with certainties, he shall end with doubts,
    but if he will be content to begin with doubts he shall end in certainties. Francis Bacon

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to John Larkin on Thu May 26 21:07:57 2022
    On 5/26/2022 8:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1




    Maybe an appropriately-selected ferrite bead for the gates but perhaps
    not a gate resistor or anything elaborate for the LT4444, looks like
    they figure their adaptive shoot-thru protection can prevent any
    misbehavior & that kind of fancy is what you pay the LTC device price
    for I suppose.

    Looks like just a fat trace is what they recommend.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From jlarkin@highlandsniptechnology.com@21:1/5 to All on Thu May 26 18:34:24 2022
    On Thu, 26 May 2022 20:08:25 -0500, John S <Sophi.2@invalid.org>
    wrote:

    On 5/26/2022 7:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two
    secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1

    Oh. So you don't want to buy one or need help. You just feel compelled
    to tell us about it, right?

    It's an electronic design discussion group.

    Design something. Discuss it. Or whine. Whatever you're best at.





    --

    Anybody can count to one.

    - Robert Widlar

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From jlarkin@highlandsniptechnology.com@21:1/5 to bitrex on Thu May 26 19:08:21 2022
    On Thu, 26 May 2022 21:07:57 -0400, bitrex <user@example.net> wrote:

    On 5/26/2022 8:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two
    secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1




    Maybe an appropriately-selected ferrite bead for the gates but perhaps
    not a gate resistor or anything elaborate for the LT4444, looks like
    they figure their adaptive shoot-thru protection can prevent any
    misbehavior & that kind of fancy is what you pay the LTC device price
    for I suppose.

    The LTC4444 is about $2.80. That's in the noise floor for this board.

    The three half-bridges are more voltage, so need the UCC27712. It's
    more like $1 so I may as well use it everywhere.


    Looks like just a fat trace is what they recommend.

    Gate resistors might be prudent, stuffed as 0 ohms initially. Could be
    a resistor or bead if needed.

    I might also put schottky diodes across the fets, in case the
    substrate diodes get weird. Excess caution in both cases.



    --

    Anybody can count to one.

    - Robert Widlar

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From DecadentLinuxUserNumeroUno@decadenc@21:1/5 to John S on Fri May 27 03:48:29 2022
    John S <Sophi.2@invalid.org> wrote in
    news:t6p8ag$iuu$2@dont-email.me:

    On 5/26/2022 7:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need
    a roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts,
    surface mount, under a cubic inch. They have a 4t tapped primary
    and the two secondaries are available with 4, 5, 6, 7, or 8 turns
    each. That has a lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=
    1

    Oh. So you don't want to buy one or need help. You just feel
    compelled to tell us about it, right?



    Pre fashioned, vertically mounted POL devices have been massaged
    out pretty good. No need to try to design your own power source if
    the pros already did the hard works for you and offer a far less
    expensive solution than spending your own time trying to fashion your
    own device. And most folks doing that examine and copy features from
    the big boys as well. A bit of a cheat.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From DecadentLinuxUserNumeroUno@decadenc@21:1/5 to jlarkin@highlandsniptechnology.com on Fri May 27 03:55:04 2022
    jlarkin@highlandsniptechnology.com wrote in news:2la09ht44t87nlhccjm2660suj06t91gp7@4ax.com:

    On Thu, 26 May 2022 21:07:57 -0400, bitrex <user@example.net>
    wrote:

    On 5/26/2022 8:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I
    need a roughly +-60 volt floating power supply. It will feed
    three PWM half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts,
    surface mount, under a cubic inch. They have a 4t tapped primary
    and the two secondaries are available with 4, 5, 6, 7, or 8
    turns each. That has a lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw
    =1




    Maybe an appropriately-selected ferrite bead for the gates but
    perhaps not a gate resistor or anything elaborate for the LT4444,
    looks like they figure their adaptive shoot-thru protection can
    prevent any misbehavior & that kind of fancy is what you pay the
    LTC device price for I suppose.

    The LTC4444 is about $2.80. That's in the noise floor for this
    board.

    The three half-bridges are more voltage, so need the UCC27712.
    It's more like $1 so I may as well use it everywhere.


    Looks like just a fat trace is what they recommend.

    Gate resistors might be prudent, stuffed as 0 ohms initially.
    Could be a resistor or bead if needed.

    I might also put schottky diodes across the fets, in case the
    substrate diodes get weird. Excess caution in both cases.




    For the primary, build a trough on the PCB where you then add a nice
    Silver Plated Copper wire, or get a custom wire formed and stamped to
    lay in the trough. Done. Your primary is of a large capacity wire
    now, instead of a circuit trace. Then make a nice 0.032 secondary
    PCB to sit under your core element. The is for the planar
    transformer.

    I think we used Transzorbs and beads on the FET leads.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jan Panteltje@21:1/5 to jlarkin@highland_atwork_technology. on Fri May 27 05:27:58 2022
    On a sunny day (Thu, 26 May 2022 17:16:56 -0700) it happened John Larkin <jlarkin@highland_atwork_technology.com> wrote in <uh509h9ki5momgqptatnult0fnkagcf7e8@4ax.com>:

    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two >secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1

    Interesting circuit.
    In the long ago past I used zeners between source and gate to protect against drain-gate spike injection.
    Dunno much about this driver chip..
    The zeners however caused oscillations to occur at many MHz, a few nF caps between drain and source killed that.
    Scope the thing! Maybe some gate resistors too?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From piglet@21:1/5 to John Larkin on Fri May 27 09:57:03 2022
    On 27/05/2022 1:16 am, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1




    Neat transformer! How much do they weigh? I'd be wary of relying just on surface mount pads on anything over a couple grams in case the unit gets dropped one day.

    piglet

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to jlarkin@highland_atwork_technology. on Fri May 27 08:11:17 2022
    On Thu, 26 May 2022 17:16:56 -0700, John Larkin <jlarkin@highland_atwork_technology.com> wrote:

    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two >secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1

    Take care. Chances are, core loss estimates are for a regulated
    system with '48V' input. For straight DC-DC unregulated, your
    flux swings will be double the typical application for 48V 'primary',
    and triple for a 60V 'primary' - core losses scale with a positive
    exponent greater than one.

    You might make this up due to lower current and crest factor in the
    copper, but . . .

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From jlarkin@highlandsniptechnology.com@21:1/5 to All on Fri May 27 07:52:07 2022
    On Thu, 26 May 2022 19:08:21 -0700, jlarkin@highlandsniptechnology.com
    wrote:

    On Thu, 26 May 2022 21:07:57 -0400, bitrex <user@example.net> wrote:

    On 5/26/2022 8:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two
    secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1




    Maybe an appropriately-selected ferrite bead for the gates but perhaps
    not a gate resistor or anything elaborate for the LT4444, looks like
    they figure their adaptive shoot-thru protection can prevent any >>misbehavior & that kind of fancy is what you pay the LTC device price
    for I suppose.

    The LTC4444 is about $2.80. That's in the noise floor for this board.

    The three half-bridges are more voltage, so need the UCC27712. It's
    more like $1 so I may as well use it everywhere.


    Looks like just a fat trace is what they recommend.

    Gate resistors might be prudent, stuffed as 0 ohms initially. Could be
    a resistor or bead if needed.

    I might also put schottky diodes across the fets, in case the
    substrate diodes get weird. Excess caution in both cases.

    Take a look at the UCC27712 data sheet, fig 44. It's absolutely
    decorated with parts.

    With 150 ns of anti-shoot delay, why all that gate junk?

    The LTC works fine without all that stuff. 98 more parts if I use the
    TI as shown on my board.



    --

    Anybody can count to one.

    - Robert Widlar

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From jlarkin@highlandsniptechnology.com@21:1/5 to DecadentLinuxUserNumeroUno@decadenc on Fri May 27 07:53:59 2022
    On Fri, 27 May 2022 03:55:04 -0000 (UTC), DecadentLinuxUserNumeroUno@decadence.org wrote:

    jlarkin@highlandsniptechnology.com wrote in >news:2la09ht44t87nlhccjm2660suj06t91gp7@4ax.com:

    On Thu, 26 May 2022 21:07:57 -0400, bitrex <user@example.net>
    wrote:

    On 5/26/2022 8:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I
    need a roughly +-60 volt floating power supply. It will feed
    three PWM half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts,
    surface mount, under a cubic inch. They have a 4t tapped primary
    and the two secondaries are available with 4, 5, 6, 7, or 8
    turns each. That has a lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw
    =1




    Maybe an appropriately-selected ferrite bead for the gates but
    perhaps not a gate resistor or anything elaborate for the LT4444,
    looks like they figure their adaptive shoot-thru protection can
    prevent any misbehavior & that kind of fancy is what you pay the
    LTC device price for I suppose.

    The LTC4444 is about $2.80. That's in the noise floor for this
    board.

    The three half-bridges are more voltage, so need the UCC27712.
    It's more like $1 so I may as well use it everywhere.


    Looks like just a fat trace is what they recommend.

    Gate resistors might be prudent, stuffed as 0 ohms initially.
    Could be a resistor or bead if needed.

    I might also put schottky diodes across the fets, in case the
    substrate diodes get weird. Excess caution in both cases.




    For the primary, build a trough on the PCB where you then add a nice
    Silver Plated Copper wire, or get a custom wire formed and stamped to
    lay in the trough. Done. Your primary is of a large capacity wire
    now, instead of a circuit trace. Then make a nice 0.032 secondary
    PCB to sit under your core element. The is for the planar
    transformer.

    The Coilcraft is stock and is pick-and-place. That's sure easy.



    I think we used Transzorbs and beads on the FET leads.


    --

    Anybody can count to one.

    - Robert Widlar

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dimiter_Popoff@21:1/5 to John Larkin on Fri May 27 19:47:52 2022
    On 5/27/2022 3:16, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1




    The transformer certainly looks very interesting, thanks for posting.

    I don't check on that sort of products frequently enough (not being in
    high quantities and being battle hardened by winding in house our
    5kV transformers, recently there was a hiccup running out of 0.07mm
    wire... one of the attempts to get new supply ended me up with about
    100-200 grams of.... 130 Ohm/meter 0.07 wire, noticed it after I
    got home :).
    I'll explore these now though.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to pNaonStpealmtje@yahoo.com on Fri May 27 11:05:34 2022
    On Fri, 27 May 2022 05:27:58 GMT, Jan Panteltje
    <pNaonStpealmtje@yahoo.com> wrote:

    On a sunny day (Thu, 26 May 2022 17:16:56 -0700) it happened John Larkin ><jlarkin@highland_atwork_technology.com> wrote in ><uh509h9ki5momgqptatnult0fnkagcf7e8@4ax.com>:

    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM >>half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two >>secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1

    Interesting circuit.
    In the long ago past I used zeners between source and gate to protect against drain-gate spike injection.
    Dunno much about this driver chip..
    The zeners however caused oscillations to occur at many MHz, a few nF caps between drain and source killed that.
    Scope the thing! Maybe some gate resistors too?


    I've used the LTC4444 before and it works great with no gate
    resistors. But in my output stages I need more voltage than it can
    handle, hence the UCC27712 part.

    Maybe I'll hack a proto board with the TI, to avoid surprises.

    --

    If a man will begin with certainties, he shall end with doubts,
    but if he will be content to begin with doubts he shall end in certainties. Francis Bacon

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to DecadentLinuxUserNumeroUno@decadenc on Fri May 27 11:01:48 2022
    On Fri, 27 May 2022 03:48:29 -0000 (UTC), DecadentLinuxUserNumeroUno@decadence.org wrote:

    John S <Sophi.2@invalid.org> wrote in
    news:t6p8ag$iuu$2@dont-email.me:

    On 5/26/2022 7:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need
    a roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts,
    surface mount, under a cubic inch. They have a 4t tapped primary
    and the two secondaries are available with 4, 5, 6, 7, or 8 turns
    each. That has a lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=
    1

    Oh. So you don't want to buy one or need help. You just feel
    compelled to tell us about it, right?



    Pre fashioned, vertically mounted POL devices have been massaged
    out pretty good. No need to try to design your own power source if
    the pros already did the hard works for you and offer a far less
    expensive solution than spending your own time trying to fashion your
    own device. And most folks doing that examine and copy features from
    the big boys as well. A bit of a cheat.

    Where would I buy a 48v to +-60 volt isolated 200 watt dc/dc
    converter? What would that cost?

    My circuit will cost maybe $20. Besides, designing things is what I
    do.

    --

    If a man will begin with certainties, he shall end with doubts,
    but if he will be content to begin with doubts he shall end in certainties. Francis Bacon

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to All on Fri May 27 11:15:49 2022
    On Fri, 27 May 2022 09:57:03 +0100, piglet <erichpwagner@hotmail.com>
    wrote:

    On 27/05/2022 1:16 am, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I need a
    roughly +-60 volt floating power supply. It will feed three PWM
    half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts, surface
    mount, under a cubic inch. They have a 4t tapped primary and the two
    secondaries are available with 4, 5, 6, 7, or 8 turns each. That has a
    lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?raw=1




    Neat transformer! How much do they weigh? I'd be wary of relying just on >surface mount pads on anything over a couple grams in case the unit gets >dropped one day.

    piglet

    22 grams. It has 9 giant nail-head pins. Should be fine.

    --

    If a man will begin with certainties, he shall end with doubts,
    but if he will be content to begin with doubts he shall end in certainties. Francis Bacon

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From DecadentLinuxUserNumeroUno@decadenc@21:1/5 to John Larkin on Sat May 28 03:18:58 2022
    John Larkin <jlarkin@highland_atwork_technology.com> wrote in news:h8429h9rsii1vur3sv33o2v8dd86omf94i@4ax.com:

    On Fri, 27 May 2022 03:48:29 -0000 (UTC), DecadentLinuxUserNumeroUno@decadence.org wrote:

    John S <Sophi.2@invalid.org> wrote in
    news:t6p8ag$iuu$2@dont-email.me:

    On 5/26/2022 7:16 PM, John Larkin wrote:
    I'm designing another 3-phase PM alternator simulator, and I
    need a roughly +-60 volt floating power supply. It will feed
    three PWM half-bridges to make the three output phases.

    Here's my first pass at the dc/dc thing.

    https://www.dropbox.com/s/bwt1vgbb2j94p1d/23S942_x1.jpg?raw=1

    Those Coilcraft planar transformers are radical. 300 watts,
    surface mount, under a cubic inch. They have a 4t tapped
    primary and the two secondaries are available with 4, 5, 6, 7,
    or 8 turns each. That has a lot of possibilities.

    https://www.dropbox.com/s/3d093msdmuinhxs/Coilcraft_PL300.jpg?ra
    w= 1

    Oh. So you don't want to buy one or need help. You just feel
    compelled to tell us about it, right?



    Pre fashioned, vertically mounted POL devices have been massaged
    out pretty good. No need to try to design your own power source
    if the pros already did the hard works for you and offer a far
    less expensive solution than spending your own time trying to
    fashion your own device. And most folks doing that examine and
    copy features from the big boys as well. A bit of a cheat.

    Where would I buy a 48v to +-60 volt isolated 200 watt dc/dc
    converter? What would that cost?

    I doubt there is much market for that in a POL scenario, which is
    what I spoke on. A small PCB. Maybe I did not read the original
    thread, because I would not have answered with POL had I seen the
    numbers you gave.

    48V to +-60V @ 200W is a little big for that form factor.

    My circuit will cost maybe $20. Besides, designing things is what
    I do.

    DC to DC converters are things which power engineers spend years
    massaging.

    At a mere $20 outlay, I doubt you will get the DC power you desire.
    PARD and other elements make it hard to get right the first time. If
    noise is an issue with the circuit, you may have a hard time
    providing that DC power cleanly in a one off first time doing it
    design. And then there is the cubic inches of space you pack it all
    into, and the operating efficiency numbers.

    Lots of reasons to use the boys that have been doing it for
    decades, especially if the input power requirements of the circuits
    require it to be clean and free of noise throughout it load range.
    Good luck.

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