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🔌General Home Automation => Automating Your House => Troubleshooting Automation Problems => Topic started by: phs3 on November 24, 2007, 11:30:46 PM

Title: TM751 "leaks" current?
Post by: phs3 on November 24, 2007, 11:30:46 PM

I added a TM751 and a couple of lamp modules to my system to control my indoor Christmas tree and a couple of other small Christmas displays (all inside the house).  Setting up just now, I have all hooked up except the tree itself, which will be plugged into the TM751 via an extension cord.  Also plugged into this same extension cord are two very small lights: they're streetlights that have special bulbs that flicker like flames.  They work fine when the TM751 is on.

Here's where it gets weird: when the TM751 is off, they still flicker faintly.  I'm not imagining it -- if I unplug them, it stops.

I can move the TM751 to another part of the setup and avoid this, but I'm concerned that it means something worse is going on.

Has anyone seen anything like this?  I suppose I could throw a VOM across it and see what it's leaking, once I find my VOM ...

Thanks for any info anyone can provide!

Title: Re: TM751 "leaks" current?
Post by: KDR on November 25, 2007, 06:44:45 AM

hi  phs3
the outlet on a TM751 acts like an appliance module and responds only to the house code set and unit code 1. It also has local current sensing.
Take a look at  Topic: Controlling LED Christmas Lights  (Read 3004 times)  (http://www.x10community.com/forums/index.php?topic=7030.0).  You can also do a search on "current sensing" (include the quotes) and you will come up with more good reading info.

_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^----KDR

Title: Re: TM751 "leaks" current?
Post by: Brian H on November 25, 2007, 07:19:49 AM

With no load on the TM751 and a high impedance meter you may see a fairly high voltage. This is normal but has limiting components so a low impedance normal lamp may only show a few tenths of a volt. It is the sensing current as KDR mentioned.

Title: Re: TM751 "leaks" current?
Post by: phs3 on November 25, 2007, 10:48:01 AM

Thanks.  Guess I'll move the TM751 to one of the other locations, where it'll just be "tickling" a regular, cheap bulb!  At least I'm not worried that it's broken...

Title: Re: TM751 "leaks" current?
Post by: Brian H on November 25, 2007, 10:50:57 AM

The other choice is a small 4 watt night light bulb on the output with the LED lights. One of those power taps could be used.

Title: Re: TM751 "leaks" current?
Post by: phs3 on November 25, 2007, 12:22:43 PM

Quote from: Brian H on November 25, 2007, 10:50:57 AM

The other choice is a small 4 watt night light bulb on the output with the LED lights. One of those power taps could be used.

Ah -- I haven't hooked the tree (conventional minilites) up yet; you're suggesting that those bulbs will "suck" the current enough that the expensive flicker bulbs (which aren't LED) won't flicker when it's off?  In that case, it's a non-problem.  I'll experiment...thanks!

Title: Re: TM751 "leaks" current?
Post by: phs3 on November 25, 2007, 12:35:14 PM

Hmm...I swapped the TM751 for a lamp module, and the problem persists.  But when I put another load on the circuit (downstream of the lamp module, of course), it stops.  So I assume once I lug the tree up and get it hooked up, this will be a non-issue.

Thanks to all for their assistance!

Title: Re: TM751 "leaks" current?
Post by: KDR on November 25, 2007, 12:47:24 PM

The lamp module also has current sensing as do appliance modules. The local current sensing is what allows you to turn on a light or appliance from the local switch.

In most cases a 4 to 7 watt incandescent load as Brian H indicated along with the device being controlled will stop the flicker. More lights to the circuit may do it but watch that you don't exceed the watt rating of the module.

_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^---_{(http://www.bdshost.com/X10/lpup.gif)}^----KDR