How to use X10 to protect a plasma screen?

A 110V relay could easily be wired with a momentary contact button/switch in an electrical box to do this. Wire the relay so the relay contact closes to turn on the power to the TV and to the relay coil. Wire the momentary contact switch across the relay contacts. Pushing the switch will activate the relay, which will then stay on until power goes away. It will then stay off until power comes back on, followed by the switch being activated again.

This could be built inside a standard electrical outlet or double outlet box, depending on the relay and switch size. A standard wall outlet on the box to plug the TV into, and a cord coming out to plug into the wall. "Outdoor" type boxes might look better.

The relay and switch would both have to be sized for the load.

Unfortunately, consumer electronics are not designed with power outages in mind. Instead, they are often designed to come back on when power is restored. This is okay in some cases, but very bad in the case of a plasma TV, because when a static image is displayed on a plasma TV for a couple of hours, it burns the image into the TV permanently, destroying it.

We already lost one plasma TV this way!

I want to protect our new TV with a simple device that won?t send power to the TV until I press a reset button.

The device would have the following states:

• No power in house: no power to TV

• Power in house, reset button not pressed: no power to TV

• Power in house, reset button pressed: power to TV

It?s a very simple device, but I have not been able to find one off the shelf. All of the X10 power controllers I've seen (and I've called a number of vendors) restore themselves to their previous state when powered on, so if they were powering the TV when the power went out, they'll restore power to the TV when PG&E restores power to the house.

Can someone on this forum help me solve this problem using X10? I can write software (including assembly code) if that's necessary, but I would need some guidance about what programmable controller to get, etc.

As posed, this can be accomplished with 1) a Normally Open (NO) Double-Pole, Single-Throw (DPST) relay with a 120VAC actuation coil and contacts with an amp rating sufficient for your plasma TV and 2) a SPST 120VAC momentary contact switch to serve as a re-set switch. (A DPDT relay could also be used; the normally closed contact would be unused in this application.)

1) Wire one of the contacts (poles) of the Normally Open SPDT relay in series with 120VAC provide power to the TV when the relay is closed. 2) Wire the other NO pole in series with actuation coil and the 120VAC power. When power is applied, the coil will not initially be energized owing to the open NO SPST contact. 3)Wire a momentary contact SPST switch adequate for 120VAC across (parallel to; 'shorts out') this relay contact. When this switch is pressed, it provides power to the relay coil which then is latched on through the now-closed contact. It will stay on even if the re-set switch is open because the power to the relay coil is now provided through the closed relay contact. It will stay on until 120VAC is interrupted and then will stay off until the re-set switch is momentarily closed.

HTH ... Marc

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Marc_F_Hult

Yes, it can be done with relays. But I was hoping it could be done with an X10 module, so I don't have to source relays, solder wires, make an enclosure, etc., and also so I don't have to expose a reset switch.

My first thought was a double pole relay also. But the extra pole really is not necessary, as long as the momentary contact switch can handle the needed output turn on surge.

The X10 standard appliance module has a "relay" that toggles on/off mechanically, so it remembers its last position through a power down. That one won't work. I don't know if their wall outlets do the same. X10 modules generally have sensing to turn on if the device they operate turns off then on. Electronic devices like a TV may well turn them on by themselves due to phantom currents.

How about using a power strip that lets some other device act as the master? That is, the strip only powers on the other sockets when it detects active use on one of them? I've seen it in the past, and just this past weekend on an APC UPS (a consumer grade, power strip style UPS).

Have you looked into whether the TV has the option to remain powered off? Is it perhaps buried in a menu somewhere? Or in a service menu? What make/model is it? Some even have a 'sleep mode' that will turn itself off after not seeing any IR remote inputs for a configurable time.

-Bill Kearney

I remember complaining about the opposite problem. About 3 decades ago, when I first started using X10 modules, I complained that the X10 appliance modules would go off when the power went off and not come back until they were commanded to. I wanted them to keep the original state. This was with rather primitive controllers that had no memory state whatever, much less memory state across power failures.

I think later they came up with modules that would fail-previous-state, rather than fail-off, but they kept the fail-off modules for use with, say, coffee pots or space heaters.

You might test the modules by setting one up with a lamp on a switched outlet, then simulate a power failure by operating the switch.

The TV has a lot of options to configure it, but nothing guaranteed to make it stay off if the power goes off. It's not something they seem to have taken into consideration. It's a Pioneer Kuro Pro-141FD. It might be possible to get it to look for an "integrator" input and, failing that, stay off, but then I have to reset the input every time I turn it on.

I thought about a UPS or power strip, but there's no good location for it where the TV is.

That's what seemed resonable, but every X10 vendor I've contacted says they don't have anything like that.

On a different forum, I got the following response:

"I had a similar (but much less expensive) problem--anytime power went out and was restored to our home, then reading lights over our bed would turn on--even if they were off when the power failed.

I use an Ocelot controller for my X10 equipment, so I just programmed it to turn off everything that should be off when the power is restored. The reading lights still come on when the power is restored, but are now turned off by the Ocelot within about 2 seconds. Using the Ocelot, you should be able to accomplish what you want--either by using it to control an appliance module to turn the TV on and off, or by using an IR emitter to send a TV OFF code to turn the TV off (allowing it to keep power for memory, clock, etc). I'm sure there are other brands of controllers that would allow the same thing."

I believe they have the IR input sleep option. Set that to a short enough time to avoid excessive burn-in.

Yup ;-) (And the wiring also needs to be adequate/code-compliant in the case of a remote reset switch.)

The double-pole approach has the virtue of being adaptable to switching

120VAC using most any AC or DC control voltage by choosing a relay with the appropriate coil and a providing a power supply for the relay coil. A low-voltage coil (eg 5vdc or 12vdc) lends itself to safe and simple interconnection with home automation control systems.

Having an X-10 module power a SPST 120VAC relay (with or without a small load like an appliance lamp across the coil) rather than the TV directly might serve to eliminate module's local turn-on feature. But the OP seems willing to (re?)program a PIC but not solder, so this probably wouldn't help him even if it did work.

... Marc

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Marc_F_Hult

wrote com...

I still think that the relay system is the easiest and most reliable.

A box A relay A push button switch A line cord An outlet A few wires.

You only need to push the button if the power goes out. Unless it is a frequently occurrence, it could be tucked out of sight somewhere.

If might be possible to find an outlet strip with enough room but then you probably want to go with a larger relay to run everything that could be plugged into it. If you only use it with the TV, you could make it with a relay sized for the one device.

That would seem to be explicit and unambiguous in your post's subject too ("How to use X-10 ..." ;-)

In my opinion, you would be wise to eliminate X-10 dimmers from consideration lest they accidentally are dimmed and damage the plasma screen.

Here's an on-off Single Wall Receptacle that is _not_ the known-bad SR-277 and that Leviton indicates has "local control disabled" and "Will not respond to ALL LIGHTS ON command". Remains to be seen whether it remembers state after a power failure. No indication that this is a 'feature', so it may not (in part for safety reasons).

Smarthome sells them.

Have you already asked Leviton or Smarthome about the power failure recovery state of these _particular_ receptacles?

HTH ... Marc

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Marc_F_Hult

It can not be done soley with X10. ALL the appliance modules, receptacles, etc that X10 produces use the same solenoid/cam switch, that maintains the previous state after a power loss. To my knowledge Samrthomes Insteon/X10 appliance modules also maintain previous state, although you might call them to confirm. If you want X10 for the remote control capabilities you will need to build the relay / outlet strip set-up.

I can help with the sourcing ordeal.

If you use the suggested relay you can power it from a Lamp Module or a Socket Rocket (with adapters). Either will remain in the OFF state after a power failure, until turned back ON with an X10 command.

Question: do you have problems with other static images? These could be a problem also. I'm thinking of:

- TiVo or other DVR or DVD menus

- Station test patterns

- A blue screen presented by a VCR, DVR, or converter box indicating that there is no signal on that channel (e.g. after the tape runs out). Some converter boxes present a "no signal" box that jumps around the screen a bit every 10 seconds or so, but the edges get a constant signal and the center spaces get a mostly-constant background.

- Game systems connected to the TV.

- Channels presenting largely static data like weather radar continuously, or for that matter the bar at the top and bottom of the screen during football games presenting scores and other stats.

TiVo menus appear to be not entirely static but it's not at all obvious that there's enough motion to avoid burn-in.

They'll kick out of the menus after a delay and switch to live video, presuming there's anything there. They will not stay on the menus if there's no user interaction. This has been the case for as many Tivo software revisions as I can recall.

-Bill

It sound's like you are attempting to build a magnetic switch. They are commonly used on stationary power tools (ie table saws and such) . You can buy them and adapt the input/output as needed.

Jim