Help Building a USB-Controlled USB Outlet?

Guest
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
 
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 :)
 
<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
Click to expand...
http://www.futurlec.com/Relay_4.shtml

and

http://www.futurlec.com/USB.shtml

You will also need a 5V wall adapter to power the relay board.

About $50 not counting the adapter.

The problem will be building the interface between the USB module and the
relay card.

I can't tell from the specs in the link, but the USB module can probably be
programmed to make pins go up and down. They claim to have "Easy Setup and
Full Instructions".

I'm also guessing here, but the relay card probably uses a single pin per
relay as control. When it goes to 5V, the relay closes, when it goes back to
ground, the relay opens.

If you are lucky, the USB card will output enough power for the relay card,
and you won't need the adapter/plug.

Send a question to the Futurlec guys here:

http://www.futurlec.com/Help.html

They have been very helpful to me in the past.

Good luck.

Regards,
Bob Monsen
 
Have a look at Diolan.com




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

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
Click to expand...
 
<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
Click to expand...
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
 
"Earl Kiosterud" <someone@nowhere.com> wrote in message
news:Q8Y_j.2959$4c.2681@trnddc08...
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.
Click to expand...
 
Frank wrote:
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
Click to expand...
If you instead use your serial port, you can control a solid state relay
(see http://en.wikipedia.org/wiki/Solid_state_relay) with a modem control
signal, DTR. Up = on, Down = off. The program to do this is trivial. You
could even use one of these to make it easier to build:

http://www.futurlec.com/Mini_RS232_TTL_5V.shtml

If you get ambitious, you could even build something that would live on the
serial line, and allow control of multiple devices using a multidrop.

If you really need it to be USB, you could go with something like one of
these:

http://www.futurlec.com/USB.shtml

Here is a nice solid state relay you could use:

http://cgi.ebay.com/Solid-State-Relay-SSR-24-220V-DC-40A-Heat-Sink_W0QQitemZ230254622839QQihZ013QQcategoryZ36328QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Regards,
Bob Monsen
 
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...
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
Click to expand...
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top