Building a Current Actuated Receptacle


For locations and equipment that does not need surge suppression is it easy to make a simple power strip from standard electrical components. Duplex receptacles, electrical boxes, cover plates, and wire are easy to obtain at your local building supply outlet. You can have quality equivalent to the built-in outlets in the wall rather than the cost dominated designs typical of cheap power strips and extension cords.

The Duplex Receptacle

The grounding receptacle has three connections, live power, power return, and safety ground.

The large rectangular hole, 4, is connected to the return side of the AC power line and is plated with a silver color. White wire is used. This wire is connected to ground at the circuit breaker box.

The small rectangular hole, 3, is connected to the hot side of the AC power line and is plated with a gold color. Black wire is usually used. If the power is switched another color may be used.

The "U" ground, 5, is connected to earth ground and is usually painted green. Connection to the U ground is usually provided by a screw at one end, 1, but it is also connected to the mounting metalwork. Green insulated wire or bare copper may be used.

The duplex can be mounted either by a single screw in its center or with two screws at the ends, 7.

Connections are by screw terminals, 2, 6, or by spring loaded wire grippers. Easily broken metal strips connect the two halves so the two circuits can be connected separately

Connecting the CARD and relay

Join all of the white return wires, 1. Use the silver terminals on the duplex receptacles. Include one of the wires from the current actuated relay driver, 2.

One ground connection, 3, is sufficient for metal boxes. If you're using a plastic box be sure all receptacles are grounded. Green wire is commonly used, sometimes with a yellow stripe.

Break one shorting bar, 4, on the gold terminals and connect to the hot (black) power wire, 5, while passing through the hole in the current actuated relay driver. You may want to pass through the CARD twice or more depending on the switching sensitivity desired. The wire used here needs only to provide the expected maximum current used by the controlling device. This will be the controlling outlet. Mark it with paint or tape. Nail polish works well. Wire nuts are an effective connection device when inside of a protective box.

Connect the arm of the relay and one side of the coil to the hot (black) power line, 6.

Connect the normally open contact of the relay, 7, to the gold terminals of the receptacles which are to be controlled. It is traditional to use a red wire here.

Connect one wire from the current actuated relay driver to one side of the relay coil, 8.


These suggestions require a certain amount of knowledge and skill. It's possible to burn a house down or hurt yourself by doing something stupid. Please don't do either of those. By hooking this up yourself you are accepting responsibility for your actions.

© 2001 The MacNauchtan Laboratory. All rights reserved.