X10 wierdness with xmtr in backgound seq

[khays]

I am seeing some strange behavior with an X10 appliance module. I use 3. 2 on the same code (E6) for snow machines and one on D6 for my transmitter (EDM with the supplied 12v wall wart power supply). The snow machines work without problems and are used in musical sequences only. The D6 device is only used in a 10 sec background sequence to turn on the radio.

In testing the D6 module worked as expected; on when the show started and off at the proper time after the final musical seq ended. This test was done without the radio plugged into the module. On my first night I realized that the radio did not go off after the show. I disabled shows; opened hardware utility and manually turned off the D6 code. It did in fact go off - but about 2 seconds later came back on. I did this several times.

I then unplugged the radio and tried again; it stayed off. As soon as I plugged it back in the module turned on. I repeated these steps but reversed the polarity of the plug when I plugged it back in - it stayed off.

I have had to do this each night so far. Each night going back to the polarity that caused grief the day before.

I am missing something. Anything sound familiar to the X10/background experts out there.

[Steven]

X10 modules have a "local on" feature. This is typically used when controlling lamps so if you come into a dark room with a lamp plugged into an X10 module, you don't have to find the X10 transmitter - you can just turn the light off and back on within a second or two and the X10 module will switch on.

This "local on" feature works fine with incandescent lights, but can cause false triggers when plugged into things like flourescent lamps with electronic ballasts or switching power supplies (like the one supplied with the EDM LCD).

What's probably happening is that when switched off, the X10 module is supplying a very small amount of current through the device (the transmitter power supply). This current is used by the "local on" feature to detect when the user turns the device off and on.

However, in the case of the switching power supply, this small amount of current slowly charges the input capacitor, which will then discharge when it tries to start the power supply after it gets enough charge. This causes the input current to fluxuate, which makes the X10 module think you are turning the device off and on, so it thinks you want the device back on.

The good news is that this is really easy to fix. Plug a 3-way (or 2-way) power splitter into the X10 module, plug the transmitter power supply into 1 outlet, and plug a small light bulb (like a 4-watt incandescent C7 bulb) into another outlet. This will keep the power supply's capacitor from charging when the X10 module is off. If you want to get fancy, you can put the 4-watt bulb behind a piece of red plastic with "ON AIR" printed on it.

[khays]

thanks Steven, I didn't know about the "local on" feature. Makes perfect sense why I was seeing those various behaviors.