Switching transformer block signals

[Mavrik]

I noticed that anytime I plug in a switching transformer anywhere in the house it blocks X10 signals. Some block when plugged in and off, others block when on.  Is there a mod that can be done to the transformers?

[JeffVolp]

Is there a mod that can be done to the transformers?

Yes, isolate it with a X10 Pro XPPF filter.

See this report on a cellphone charger that is a horrendous noise source:

    http://jvde.us/x10/x10_cellet_noise.htm

Jeff

[Brian H]

I would also say XPPF or another brand X10 type power filter is needed. For that switching supply.

[Mavrik]

Do you have an electronics diagram? 

[Brian H]

Probably easier to just buy a X10 designed filter than make one.

There are some filter schematics on this site.
Leviton 6287 and 6288. ACT AF120.
http://www.idobartana.com/hakb/index.htm

The Smarthome FilterLinc
http://home.comcast.net/~gafield/family/gary/electronics/X10_Filter.pdf

If you do build a filter. Use capacitors rated for power line use. Some standard ones can short out or open up.

There would be very little you can do directly to the switching supply itself.

[Mavrik]

Thank you

[dhouston]

I noticed that anytime I plug in a switching transformer anywhere in the house it blocks X10 signals. Some block when plugged in and off, others block when on.  Is there a mod that can be done to the transformers?

There's nothing you can do to the transformers themselves - as others have suggested you can use a filter.

What voltage/current rating are the transformers that are giving you trouble? Part Number?

I tested 3 that are X-10 friendly. I'll try to find the PN for one that came from Mouser as well as another from another supplier - I may have published them in my article on X-10 noise. This one from Smart Fun was OK...

• http://www.sparkfun.com/products/8269

However, there's no guarantee that one you buy today will have the same internals. Still, it might be helpful to start a list of those known to be friendly/unfriendly.

EDIT: Well, d'uh - I wrote a short article about SMPS and X-10, listing both those referenced above.

• http://davehouston.org/switchmode.htm