24V to 48V step-up

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Can anyone recommend a chip to convert 24V DC to 48V DC? Someone told
they exist and that the output current would be half the input current
in order to double the output voltage. I'm bulding a phantom power supply.

Archived from groups: rec.audio.pro (More info?)

"H" <mshoganREMOVE@dal.caREMOVE> wrote in message
news:YlzVe.168745$wr.73319@clgrps12

> Can anyone recommend a chip to convert 24V DC to 48V DC?

If you check the schematics of commercial mic preamps, you
will find that that function is often done with no chips at
all, or with a standard off-the-shelf chip like a 555 timer
acting as a source of high frequency, low voltage pulses
that feed into a traditional voltage-multiplier power
supply.

> Someone told they exist and that the output current would
> be half the
> input current in order to double the output voltage.

Conservation of energy is a rather robust physical law. ;-)

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H wrote:
> Can anyone recommend a chip to convert 24V DC to 48V DC? Someone told
> they exist and that the output current would be half the input current
> in order to double the output voltage. I'm bulding a phantom power supply.

Google for DC-DC converters
Pick one with a power rating that suits your needs.

They're not exactly a chip, but the small ones are small PCB mounting
components. There's lots of manufacturers out there making and selling them.

Anahata

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H <mshoganREMOVE@dal.caREMOVE> wrote:
>Can anyone recommend a chip to convert 24V DC to 48V DC? Someone told
>they exist and that the output current would be half the input current
>in order to double the output voltage. I'm bulding a phantom power supply.

It's not a single chip, it's going to be a hybrid module. Do a google
search on "48V dc-dc converter" and you'll find a bunch of them. It is
usually cheaper just to add an additional winding to the transformer to
get 48V, or use a voltage multiplier, though. If you're stuck with battery
power, though, the DC-DC converter is the way to go but be very careful
of noise issues.
---scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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H wrote:

> Can anyone recommend a chip to convert 24V DC to 48V DC? Someone told
> they exist and that the output current would be half the input current
> in order to double the output voltage. I'm bulding a phantom power supply.

It's not a 'chip' !

Too many ppl today seem to think there a 'chip' to do everything.

You can get a module to do this but it may be too electrically noisy - EMI etc
- than you would like..

Graham

Archived from groups: rec.audio.pro (More info?)

"Richard Crowley" <rcrowley@xpr7t.net> wrote in message
news:11idtvklv4hi2a3@corp.supernews.com
> "H" wrote ...
>> Can anyone recommend a chip to convert 24V DC to 48V DC?
>> Someone told they exist and that the output current
>> would be half the input current in order to double the
>> output voltage. I'm bulding a phantom power supply.
>
> How do you happen to have 24V DC?
> Do you have access to 24V AC (perhaps at the other side
> of the rectifier/filter)? Many pieces of equipment that
> are highly regarded in this neighborhood use voltage
> doubler circuits to create the P48 power because of the
> very modest current requirements.
>
> DC-to-DC converters are to be avoided for many reasons
> unless there is really no alternative. There is no single-
> "chip" solution to voltage conversion at this time.

Depends on how strictly you define "single chip"

The Maxim catalog has a ton of DC-DC chips. Most if not all
require outboard parts. AFAK none are designed for this
particular application. The required output voltage is on
the high side.

Archived from groups: rec.audio.pro (More info?)

Richard Crowley wrote:
>
> "Arny Krueger" <arnyk@hotpop.com> wrote in message
> news:TvydnRoZHcN7ZbveRVn-vA@comcast.com...
>
>> "Richard Crowley" <rcrowley@xpr7t.net> wrote in message
>> news:11idtvklv4hi2a3@corp.supernews.com
>>
>>> "H" wrote ...
>>>
>>>> Can anyone recommend a chip to convert 24V DC to 48V DC?
>>>> Someone told they exist and that the output current
>>>> would be half the input current in order to double the
>>>> output voltage. I'm bulding a phantom power supply.
>>>
>>>
>>> How do you happen to have 24V DC?
>>> Do you have access to 24V AC (perhaps at the other side
>>> of the rectifier/filter)? Many pieces of equipment that
>>> are highly regarded in this neighborhood use voltage
>>> doubler circuits to create the P48 power because of the
>>> very modest current requirements.
>>>
>>> DC-to-DC converters are to be avoided for many reasons
>>> unless there is really no alternative. There is no single-
>>> "chip" solution to voltage conversion at this time.
>>
>>
>> Depends on how strictly you define "single chip"
>>
>> The Maxim catalog has a ton of DC-DC chips. Most if not all require
>> outboard parts. AFAK none are designed for this particular
>> application. The required output voltage is on the high side.
>
>
> Most require inductors (the rest use capacitors). They
> are not particularly easy/convienent for casual users.
> None of them accomplish the conversion completely
> within the chip package. The power requirements all
> demand larger, exernal components. The difficulty
> of using these chips is decreasing, but there is still a
> good market for pre-engineered sub-systems.



Check out the PTI products (now from TI) with integrated inductor. Far
too noisy for this app, though.

Archived from groups: rec.audio.pro (More info?)

Tim Martin wrote:
> Well, you can build a circuit to do that - you'll need an electronics
> cookbook. I think they are called "level shifters".

More commonly known as "DC to DC converters", in my experience. Voltage
doubling should be possible. You'll get less than half the amps out due
to inefficiencies in the process.

I'd second Tim's suggestion of first seeing if you can get away with 24V.

Another solution, of course, is to swap out the power supply for one
that produces both 24V and 48V, making it Someone Else's Problem.

Archived from groups: rec.audio.pro (More info?)

"H" <mshoganREMOVE@dal.caREMOVE> wrote in message
news:y0%Ve.90450$Ph4.2864068@ursa-nb00s0.nbnet.nb.ca
> My mixer currently uses 5 9V batteries for phantom.
> Inside the boards power supply, there is a multi-tap
> transformer with 2 of it's wires disconnected from the
> main board. I read 36 VAC from this but it flickers to 0
> sometimes so there could be an internal short and that's
> why it was disconnected.
> Building my own supply seems like the way to go. I think
> I will use this design:
>
>
> http://members.aol.com/ecc81/ps48.html
>
> look good?
>

Looks like much of the contents of my Audio Technica Phantom
supply.