Design News is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Gadget Freak Case #238: Controller Adjusts Garage Lights

Thomas W. Manning created an automatic switch that uses a solid state relay to adjust the florescent lights in his garage automatically.

I installed two sets of fluorescent lights in a two-car garage as part of a renovation project. Because the ceiling has a large opening, I had to arrange the 16-foot-long rows of florescent lights parallel to the garage door opening. This setup blocked light from one row of lights when a door was open and retracted.

As an alternative to a second light switch on the wall for the lights above the door, I created an automatic switch that uses a solid state relay. The relay is housed in a double-depth four-inch octagonal junction box used for house wiring and ceiling lamps. The box attached to the wooden ceiling joist above the obstructed fluorescent lamp fixture. You can find a suitable electrical box at hardware and home improvement stores. This type of box often comes with a mounting bracket that simplifies attachment to a wooden joist.

A standard doorbell or door chime transformer provided 16VAC power for the control circuit, and this type of transformer can attach directly to the metal box. A simple circuit connected to the solid state relay control terminals rectifies the AC control voltage to provide DC to the relay. Observe the polarity of the connections to the + and - terminals on the solid state relay. A magnetic reed switch (SW2) senses when the door is open and causes the relay to turn off the lights over the opened door.

A low-voltage transformer attached to a four-inch octagonal electrical junction box.

This view inside the junction box shows the transformer (right), the solid state relay, and the rectifier diode, resistor, and capacitor attached to the + and - control inputs on the solid state relay.

Do you have a Gadget Freak project you would like the world to see? Send a brief description of your gadget and a photo to Senior Editor Rob Spiegel.

{table 1} {table 2} {videoembed|262109}

The editors of Design News have handpicked your favorite Gadget Freak cases from over the years, bringing them together in a dynamic digital edition, complete with videos, which you can view here.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.