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Home Automation Tips and Tricks Archive
August 1999

Carl Wales -  cwales@images.alaska.edu

Capacitor as a Bridge

Just a suggestion for those that want to use a capacitor for a bridge-- put it in your electric dryer (easy to install with power removed- unplug it).

Of course if you have a gas one well.....

Dave Burton - daveb@stn.net

Blind Hawkeye

I read an issue in the tips and tricks in regards to the Hawkeye II motion sensor and it controlling two units codes. The suggestion was to set the hawkeye II to unit code 16 therefore it cannot control a device at unit code 17 when it does not exist. This will work BUT what if the unit you want to control is at unit code oh say #4? Well I have the answer.

Open the Hawkeye II motion sensor case by removing the two screws located on the back. Once the case is open flip it over and you will see the circuit board with three items sitting quite high off of it. One is the red LED, one is the motion sensor itself and the last is the CDS Cell that senses light (located closest to the bottom of the unit). Now what you want to do is get a piece of black electrical tape, a piece about 3/4 of an inch long. Place this over the CDS cell and wrap it tight around the edges so that no light can leak in. Reseal the Hawkeye II case and set it up according to the instructions. Now when the hawkeye II senses motion it will turn on the preselected device however, the hawkeye now thinks it is night all the time so it will not turn on the device set to the next device code number.

Cost? Well I'm not sure how much 5 minutes and 3/4" of black electrical tape is....

Dick Gensley - dick@hometech.com (Home Tech Solutions)

Neutral Wire

A customer was in our store and asked about the importance of a neutral wire. He was under the impression that his older house may not be wired with a neutral.

I recognized he was obviously confusing a ground wire with a neutral wire. All homes are wired with neutral wires. Older homes, usually built before 1970, often do not have ground wires going to outlets and fixtures. The ground wire is either colored green or is bare copper. It was added as a wiring requirement in most jurisdictions before 1970. It provides a means of safely grounding the case of appliances to prevent shock in the event there is a breakdown of the insulation within the appliance.

All homes have neutral wires. The Neutral is the return path for the current going to a light or appliance. It is normally colored white. It will always be present at the appliance or the light fixture. It is usually present at the switch, but not always. The electrician wiring a house can run the neutral through the switch box, but he can also wire the circuit with a "switch leg" configuration where the neutral is not present at the switch box. If he uses the switch leg method, electronic switches that require a neutral can not be used. Approximately 80 percent of the time, electricians will include a neutral in the switch box.

The way to tell if you have a neutral in your switch box is to remove the cover plate and inspect the wiring. If you have a pair of wires entering the box (one black and the other white), and another pair exiting the box (again one black and one white), and the white wires are connected together, the white wires are the neutral. The black wires will each be connected to separate connectors on the switch. If instead you find there is only one pair of wires entering your switch box and those wires a connected to the switch, you have a switch leg configuration and do not have a neutral in the switch box.

Tel: 1-408-257-4406 x147

HomeTech Solutions Orders: 1-888-257-4406 10600 S De Anza Blvd Questions: 1-408-257-4406 Cupertino CA 95014 Fax: 1-408-257-4389 mailto: dick@hometech.com http://www.hometech.com

Guy Lavoie - lavoieg@netcom.ca

Testing your own repairs.

 How many times have you dismanteled an X-10 wall switch or module to repair or modify it ( I have just replaced the triac in a wall switch myself ) and wished you could test it before painstakingly putting it back together! Alas, you see the house and unit code dials lying there on the table with the other pieces, so you think these must be back in place to test the unit. Not so! The dials each encode a 4 bit pattern, so there has to be one position where none of the dial contacts touch the circuit board. If you look at the X-10 code bit patterns, you will see that this corresponds to code M 13 ! So just connect your module for testing (being extra careful with an exposed line voltage circuit board) and then set your test code tranmitter to code M and send 13 ON and 13 OFF commands. I have tried this and it works fine! As an added precautionary note, if you are testing a wall switch, do not turn it ON with a load very long, since the triac is not yet screwed to the heat sink. In finishing, Here is a way to remember this code: If you are repairing a module, bad luck probably got you there, so remember Murphey's law and the number 13 !

cost: zip....

Dave Landfried dlandfried@usa.net  Olean, NY

Use Appliance Module as In-line Module

I recently had a need for an in-line module to run a string of basement lights. Some of these lights were fluorescent and I didn't want to pay $30+ for a module when an appliance module would work. Therefore I decided to modify a module to work similar to an in-line module.

I opened the appliance module and removed the circuit card. Using a hot soldering iron, I then removed the two metal pieces that make the plug and the two metals pieces that make the receptacle. I then took some wire from an old extension cord and cut it into lengths of about 6 inches. I then soldered these wires to the circuit board where the metal tabs were. After cutting some plastic and drilling a couple of holes in the case, I fed the wires out. I then filled any excess holes with RTV (silicon rubber).

Now I had a module that could be placed into a junction box and control the downstream circuits (limited to 500W). Use caution in wiring the appliance module. It is best to maintain the proper polarity.

Cost: Two Pin Polarized Appliance Module $12.99