Step 2: Building the AC module

Picture of Building the AC module

CAUTION ! Never work on a live circuit.  Carefully route and insulate all wiring.

The AC module consists of a six way AC receptacle that has been modified with a Hall effect sensor mounted on two of the six available receptacles. Any current draw of more than 4 amps produces a 5VDC, 60 Hz square wave that can be read by the master module.  Cut a small break in the neutral lead of the two receptacle neutral wires that you want to use for the washer and dryer.  Cut a quarter inch iron bolt to about a half inch length.  Wrap  about 6 turns of #14 enameled copper wire around the bolt and solder the ends to each end of the break in the receptacle neutral.  Glue the hall switch with to the end of the bolt with the beveled side toward the bolt.  Solder the resistor between the outside leads of the hall switch.  See schematic and photo for details.  Make sure all wiring is separated and insulated properly.

The Hall switch also provides complete isolation from AC line voltages.