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Help Building a USB-Controlled USB Outlet?
   Science and Technology news... Forum Index -> Electonics - Starter Forum  
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Guest







PostPosted: Thu Jan 03, 2008 4:36 am    Post subject: Help Building a USB-Controlled USB Outlet? Reply with quote

I am a novice and would like to build a 120V AC outlet which can be switched
on and off by USB. I>m not sure what all I will need and want to make sure
that I>m not trying to do something much harder than it sounds. My end goal
is to have a single plug where I could plugin a lamp, TV, power strip, etc
and have the power to that device controller by a PC via USB port. Now I>ve
seen some devices out there like X10-compliant home automation controls and
there has always been a severe limitation in one way or another. I would
love the pulg to be grounded but it doesn>t have to be if that is a
complicating factor.

It seems to me that I need a relay which can switch the 120V on/off and then
need a USB controller to control the relay. And I have seen USB controllers
which have serial interfaces on them but then how to get from a pin or two
of a serial port to the relay is where it breaks down in my head. I>m not
sure what I need between the two or if that would even work. I can handle
the software part of it once I get a hardware solution idenfitied.

Can any of you pros offer advice to get me going in the right direction?

Thanks!
Frank
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DJ Delorie
Guest






PostPosted: Thu Jan 03, 2008 5:28 am    Post subject: Re: Help Building a USB-Controlled USB Outlet? Reply with quote

Easiest way I can think of - get a FTDI 232R chip, hook up DTR to an
opto-isolated triac driver, to a triac, to the power.

Then, at least on Linux, you can toggle DTR just by changing the baud
rate to 0 (dtr off) or anything else (dtr on) via "stty" or the
termios() functions.

The FTDI chips also have some GPIO pins you can use; in theory you can
control six outlets with one chip that way (four GPIO, plus DTR, and
RTS). You>d need to use their DLL and API to do that, though. Not a
big deal if you know how to do any programming; the API is pretty
straight-forward.

You can even get a vanilla USB to Serial adapter cable, and use DTR
off that.

I have some triac circuits here:
http://www.delorie.com/house/furnace/

But the opto-triac-power circuit is pretty common; you should be able
to find schematics all over the web. I think the triac data sheets
usually have schematics too.

Beware - messing with 120v power is dangerous. This isn>t a
beginner>s project, although I think most beginners successfully pull
it off anyway. I know I did :-)
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TonyR
Guest






PostPosted: Thu Jan 31, 2008 12:55 am    Post subject: Re: Help Building a USB-Controlled USB Outlet? Reply with quote

Have a look at Diolan.com




On Wed, 02 Jan 2008 22:36:29 +0000, noreply wrote:

[quote]I am a novice and would like to build a 120V AC outlet which can be switched
on and off by USB. I>m not sure what all I will need and want to make sure
that I>m not trying to do something much harder than it sounds. My end goal
is to have a single plug where I could plugin a lamp, TV, power strip, etc
and have the power to that device controller by a PC via USB port. Now I>ve
seen some devices out there like X10-compliant home automation controls and
there has always been a severe limitation in one way or another. I would
love the pulg to be grounded but it doesn>t have to be if that is a
complicating factor.

It seems to me that I need a relay which can switch the 120V on/off and then
need a USB controller to control the relay. And I have seen USB controllers
which have serial interfaces on them but then how to get from a pin or two
of a serial port to the relay is where it breaks down in my head. I>m not
sure what I need between the two or if that would even work. I can handle
the software part of it once I get a hardware solution idenfitied.

Can any of you pros offer advice to get me going in the right direction?

Thanks!
Frank[/quote]
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Earl Kiosterud
Guest






PostPosted: Tue May 27, 2008 11:10 pm    Post subject: Re: Help Building a USB-Controlled USB Outlet? Reply with quote

<noreply@noreply.net> wrote in message news:K_udnQr1k4NwjOHanZ2dnUVZ_oimnZ2d@giganews.com...
[quote]I am a novice and would like to build a 120V AC outlet which can be switched
on and off by USB. I>m not sure what all I will need and want to make sure
that I>m not trying to do something much harder than it sounds. My end goal
is to have a single plug where I could plugin a lamp, TV, power strip, etc
and have the power to that device controller by a PC via USB port. Now I>ve
seen some devices out there like X10-compliant home automation controls and
there has always been a severe limitation in one way or another. I would
love the pulg to be grounded but it doesn>t have to be if that is a
complicating factor.

It seems to me that I need a relay which can switch the 120V on/off and then
need a USB controller to control the relay. And I have seen USB controllers
which have serial interfaces on them but then how to get from a pin or two
of a serial port to the relay is where it breaks down in my head. I>m not
sure what I need between the two or if that would even work. I can handle
the software part of it once I get a hardware solution idenfitied.

Can any of you pros offer advice to get me going in the right direction?

Thanks!
Frank
[/quote]
You can use phidgets (www.phidgets.com) for software-controlled switched output via USB.
You>d write your own program in C, .net, VBA, etc., and they give you the API to control the
phidget output. I don>t know if there are isolated outputs, but you could use an
opto-isolator with a triac to switch the 120V power.

Do be careful -- you>re messing with the 120 V main, and your computer and other gear is
grounded. It>d be a good idea to power it from a ground-fault circuit while you>re
developing it.

--
Earl
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Art
Guest






PostPosted: Wed May 28, 2008 1:36 am    Post subject: Re: Help Building a USB-Controlled USB Outlet? Reply with quote

"Earl Kiosterud" <someone@nowhere.com> wrote in message
news:Q8Y_j.2959$4c.2681@trnddc08...
[quote]
noreply@noreply.net> wrote in message
news:K_udnQr1k4NwjOHanZ2dnUVZ_oimnZ2d@giganews.com...
I am a novice and would like to build a 120V AC outlet which can be
switched
on and off by USB. I>m not sure what all I will need and want to make
sure
that I>m not trying to do something much harder than it sounds. My end
goal
is to have a single plug where I could plugin a lamp, TV, power strip,
etc
and have the power to that device controller by a PC via USB port. Now
I>ve
seen some devices out there like X10-compliant home automation controls
and
there has always been a severe limitation in one way or another. I would
love the pulg to be grounded but it doesn>t have to be if that is a
complicating factor.

It seems to me that I need a relay which can switch the 120V on/off and
then
need a USB controller to control the relay. And I have seen USB
controllers
which have serial interfaces on them but then how to get from a pin or
two
of a serial port to the relay is where it breaks down in my head. I>m
not
sure what I need between the two or if that would even work. I can
handle
the software part of it once I get a hardware solution idenfitied.

Can any of you pros offer advice to get me going in the right direction?

Thanks!
Frank

You can use phidgets (www.phidgets.com) for software-controlled switched
output via USB. You>d write your own program in C, .net, VBA, etc., and
they give you the API to control the phidget output. I don>t know if
there are isolated outputs, but you could use an opto-isolator with a
triac to switch the 120V power.

Do be careful -- you>re messing with the 120 V main, and your computer and
other gear is grounded. It>d be a good idea to power it from a
ground-fault circuit while you>re developing it.

--
Earl
Use an Isolation Transformer during the development to make absolutely sure
you do not have any path for the hot side of the AC 120V to find it>s way
to the computer. Confirm that after development, there is no pathway for
excessive AC current to find it>s way back through the USB Cable into the
PC you are using. Both very important for your safety and longevity.[/quote]
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CDESC
Guest






PostPosted: Thu May 29, 2008 1:07 am    Post subject: Re: Help Building a USB-Controlled USB Outlet? Reply with quote

I>d suggest to hook-up a PIC 18F2550 (or something similar) to a solid state
relay. You can have plenty of outlets controlled separately with only one
USB input. Pros; well the USB stack is provided by microchip (many compilers
provide their own as well) and it>s going to be a breeze to control with a
custom software (C#).

I can give you a few quick lines on where to look and what to do if you need
details.


"Earl Kiosterud" <someone@nowhere.com> wrote in message
news:Q8Y_j.2959$4c.2681@trnddc08...
[quote]
noreply@noreply.net> wrote in message
news:K_udnQr1k4NwjOHanZ2dnUVZ_oimnZ2d@giganews.com...
I am a novice and would like to build a 120V AC outlet which can be
switched
on and off by USB. I>m not sure what all I will need and want to make
sure
that I>m not trying to do something much harder than it sounds. My end
goal
is to have a single plug where I could plugin a lamp, TV, power strip,
etc
and have the power to that device controller by a PC via USB port. Now
I>ve
seen some devices out there like X10-compliant home automation controls
and
there has always been a severe limitation in one way or another. I would
love the pulg to be grounded but it doesn>t have to be if that is a
complicating factor.

It seems to me that I need a relay which can switch the 120V on/off and
then
need a USB controller to control the relay. And I have seen USB
controllers
which have serial interfaces on them but then how to get from a pin or
two
of a serial port to the relay is where it breaks down in my head. I>m
not
sure what I need between the two or if that would even work. I can
handle
the software part of it once I get a hardware solution idenfitied.

Can any of you pros offer advice to get me going in the right direction?

Thanks!
Frank

You can use phidgets (www.phidgets.com) for software-controlled switched
output via USB. You>d write your own program in C, .net, VBA, etc., and
they give you the API to control the phidget output. I don>t know if
there are isolated outputs, but you could use an opto-isolator with a
triac to switch the 120V power.

Do be careful -- you>re messing with the 120 V main, and your computer and
other gear is grounded. It>d be a good idea to power it from a
ground-fault circuit while you>re developing it.

--
Earl
[/quote]
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