LED based DC/DC converter

T

Thomas Magma

Guest
I remember seeing a DC/DC up-converter that was based on LED's, but I can't
seem to Google it down. It was in a SOIC, I think, and it had one LED that
shined on a few to produce a higher voltage (a low current device). Does
anyone know who makes this?...or was this just some crazy dream?

Thomas
 
On Thu, 16 Jun 2005 23:47:18 GMT, "Thomas Magma"
<somewhere@overtherainbow.com> wrote:

I remember seeing a DC/DC up-converter that was based on LED's, but I can't
seem to Google it down. It was in a SOIC, I think, and it had one LED that
shined on a few to produce a higher voltage (a low current device). Does
anyone know who makes this?...or was this just some crazy dream?

Thomas
Click to expand...

You can buy p-v optocouplers that generate something like 9v at
something like 10 uA... handy sometimes. They're an led and an
integrated silicon pv stack, I think. Google "photovoltaic
optocoupler."

John
 
On Thu, 16 Jun 2005 23:47:18 GMT, the renowned "Thomas Magma"
<somewhere@overtherainbow.com> wrote:

I remember seeing a DC/DC up-converter that was based on LED's, but I can't
seem to Google it down. It was in a SOIC, I think, and it had one LED that
shined on a few to produce a higher voltage (a low current device). Does
anyone know who makes this?...or was this just some crazy dream?

Thomas
Click to expand...
Sounds like a photovoltaic optocoupler. It also provides isolation.

For example:
http://www.irf.com/product-info/datasheets/data/pvin.pdf



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Hello Thomas,

John and Spehro have already pointed out where to find them.

However, these devices usually do not provide much power. If you just
need a very highly isolated power transfer think along the lines of
contactless chargers and the like. It is possible to transfer power over
several millimeters, through PVC barriers, glass and so on.

Regards, Joerg

http://www.analogconsultants.com
 
I remember seeing a DC/DC up-converter that was based on LED's, but I can't
seem to Google it down. It was in a SOIC, I think, and it had one LED that
shined on a few to produce a higher voltage (a low current device). Does
anyone know who makes this?...or was this just some crazy dream?
Click to expand...
There are app circuits that use an LED to sense ambient light level and
adjust the drive to other LEDs to compensate- brighter when high light
level and dimmer when less light level.
 
In article <Sipse.3326$Pa5.843@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:
Hello Thomas,

John and Spehro have already pointed out where to find them.

However, these devices usually do not provide much power. If you just
need a very highly isolated power transfer think along the lines of
contactless chargers and the like. It is possible to transfer power over
several millimeters, through PVC barriers, glass and so on.
Click to expand...
You can also do small amounts of power by sending RF through a few pF and
using small Schottky diodes to rectify it. If the logic signal comes from
a CPLD or FPGA, the logic in the device can be changed to AND the signal
with the system clock. Don't expect to get a lot of power this way but it
is cheap.

--
--
kensmith@rahul.net forging knowledge
 
Hello Ken,

You can also do small amounts of power by sending RF through a few pF and
using small Schottky diodes to rectify it. If the logic signal comes from
a CPLD or FPGA, the logic in the device can be changed to AND the signal
with the system clock. Don't expect to get a lot of power this way but it
is cheap.
Click to expand...
Alternatively you could follow with a diode-capacitor cascade to
multiply. Power isn't going to be that great since many FPGA output
stage FETs won't go much below 30-40 ohms. Other times the allowed
continued load must not be exceeded.

Regards, Joerg

http://www.analogconsultants.com
 
On Fri, 17 Jun 2005 14:13:07 +0000 (UTC), kensmith@green.rahul.net
(Ken Smith) wrote:

In article <Sipse.3326$Pa5.843@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:
Hello Thomas,

John and Spehro have already pointed out where to find them.

However, these devices usually do not provide much power. If you just
need a very highly isolated power transfer think along the lines of
contactless chargers and the like. It is possible to transfer power over
several millimeters, through PVC barriers, glass and so on.

You can also do small amounts of power by sending RF through a few pF and
using small Schottky diodes to rectify it. If the logic signal comes from
a CPLD or FPGA, the logic in the device can be changed to AND the signal
with the system clock. Don't expect to get a lot of power this way but it
is cheap.
Click to expand...

And I've heard of using things called "transformers."

John
 
Hello John,

And I've heard of using things called "transformers."
Click to expand...
They can be awfully small if the frequency is high. But whenever I used
some like that and the time for the design review came people often
stared at those curly thingies on the schematic in disbelief. An analog
part in a digital module? Yeccchh.

Regards, Joerg

http://www.analogconsultants.com
 
On Fri, 17 Jun 2005 21:05:42 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Hello John,

And I've heard of using things called "transformers."

They can be awfully small if the frequency is high. But whenever I used
some like that and the time for the design review came people often
stared at those curly thingies on the schematic in disbelief. An analog
part in a digital module? Yeccchh.

Regards, Joerg

http://www.analogconsultants.com
Click to expand...

Right now, I'm designing a family of VME modules, each with 16
isolated signal conditioning channels. So I need 16 low-noise,
low-cost, zero-footprint floating power supplies. I'm thinking about
using tiny ISDN or similar telecom transformers with sinewave drive.

http://www.filtran.com/filtran/datasheets/7120.pdf

or maybe

http://www.talema.net/en/products/pdf/CFJ_Jul-03.pdf


John
 
Hello John,

Right now, I'm designing a family of VME modules, each with 16
isolated signal conditioning channels. So I need 16 low-noise,
low-cost, zero-footprint floating power supplies. I'm thinking about
using tiny ISDN or similar telecom transformers with sinewave drive.

http://www.filtran.com/filtran/datasheets/7120.pdf
Click to expand...
They also make real quad versions like the LAN transformer TTW6176.

Check Asian mfgs. I don't know what Murata carries in transformers right
now but I have used their CM chokes a lot. Good prices.

Regards, Joerg

http://www.analogconsultants.com
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top