Due to the numerous requests over the years, I am making a kit available to build your own Fan Controller. The kit includes all parts including the wall box, printed circuit board, electronic parts and the cover. The schematic below shows the updated schematic. To make the design more compact so that it will fit on one printed circuit board, the power supply has been modified. A capacitor-based supply will be used instead of the transformer. This is similar to all the millions of X-10 units that are currently in use.
The schematic of the fan controller kit. Control comes from the output of a standard wall switch.
Parts values may change, check parts list for updates.
The Fan Controller allows the use of a cheaper standard wall switch to control the fan instead of the more expensive inductive wall switch (a savings of several tens of dollars). The modification that will be needed on the wall switch is described below. The 'output' of the wall switch is simply connected to the 'control' line above.
The Solid State Relays can handle loads up to 2 Amps (240 Watts). They are very small and of the 'zero-crossing' kind, which means that this controller is not only quiet in the audio domain, but also in the RF. Your AM radio will not buzz as a result of this fan controller.
The kit is modification friendly. There are three small prototype areas where the user can install their own components for modifications. Note that in the general sense, this kit allows the control of the power delivered to a load based on a small analog voltage. It is thus possible to control other loads such as lamps and heaters based on light level (using a CDS or phototransistor sensor), temperature (using thermistors, etc), and sound (using a microphone).
Wiring the new controller into the system will require connection to four nodes in the original box
The four connections in the schematic are connected to the rest of the system as shown in the figure above. Note that this controller requires the presence of the neutral line in the original box. This is equivalent to the requirements of the inductive controller from Leviton.
Original Wall Switch with cover removed
Open the original switch by pressing the four tabs in the back corner of the unit. The above picture should result. Add the load wire by cutting the longer lead of the inductor, and then attaching a wire to it as show below. Once the wire is added, insulate it with some heat-shrink, such as the blue piece in the picture below.
Wall Switch with neutral load connection and local dimming modification added
This new wire will be the 'lamp' or load connection. In our project, it will go to the Control line of the Fan Controller. The original Black lead will be the 'Line' connection, and the Blue lead will be the 'Neutral' connection.
Next, perform the local dimming modification. This optional step allows dim-bright control of the fan by holding down the single pushbutton on the regular wall switch. In operation, you will see the LEDs on the fan controller continuously and slowly ramp up and down. When the desired speed is reached, you release the button.
Note the black electrolytic capacitor marked with the red 'X' above. With a pair of needle-nose pliers, pull the capacitor away from the board with a rocking motion. The goal is to short this capacitor out. If the cap rises above the board about 0.2" without breaking loose, you can simply twist the cap one rotation to short it. If it comes off the board with its wires remaining behind, you can short the wires with some solder.
Completed modification. Be sure to document your work with the color code of the wires and date
Once the above steps have been performed, close the switch back up and use a 'Sharpie' or equivalent permanent marker to document your work. Add a short table for the wire color code, and date your work.
My X-10 work bench. Note the Ground Fault Circuit Interrupter outlet for safety.
My work bench is shown above. I highly recommend you put together a setup such as this for safe and convenient testing and repair of X-10 units. It contains a wall outlet that is circuit breaker and Ground Fault protected for safety. It also incorporates a small mini-controller to send commands, a lamp (for a load), and a barrier strip in the middle (black). This latter part allows me to quickly hook up wall switches for repair or test. Since it is on a wooden board, I can stash it away to clear my work area until I am ready to repair units again. Visible here is the setup to test the Fan Controller.
Install in the following order:
On side with 'edcheung.com'. Note that the positive terminal (or anode) of a device is pin 1, or the square pad.
On side without 'edcheung.com'. Note that the positive terminal (or anode) of a device is pin 1, or the square pad.
The enclosure for the Fan Controller. This is a so-called 'Old Work' box. It allows the
addition of an outlet anywhere using the integral clamps. The top one is shown extended.
Circuit board mounted into the wall box. Note that the Green LED is on top, and
the potentiometer that allows you to calibrate the unit is easily accessible.
As you can see, the capacitors just about fill the box.
Rear of the completed Fan Controller. All connections are anchored
via the 4 terminal barrier strip in the back. This arrangement allows easy future
removal of the Fan Controller for repair or inspection. After the connections are made
in the wall, the barrier strip must be covered with electrical tape.
Once the board is assembled, it is mounted inside the enclosure by glueing the tops of the large 10uF capacitors onto the sides of the enclosure using a strip of double sided tape. The front blank cover is then match drilled to show the three LEDs. Alternately, you could use a clear cover to "show off" the electronics. The unit is calibrated by turning the potentiometer at the front of the board until the green LED lights up with a full ON command.
Photo of the finished installation. Note the controlling switch adjacent to the Fan Controller.