Hand Operated "Foot" Controller

By Milan Hruby
This article describes the way I have constructed switches that can be operated by my left hand to replace the functions of the four switch foot controller and the two foot switches (1 and 2). I find this setup convenient because it is easier for me to see what my hand is doing than my feet. And, the price was right. The materials for this project were available at Radio Shack for just a little over $20.00 US. This article gives a bill of materials and a wiring diagram for the project.

This is the main control box. As you can see, it has 4 mini push button switches; one for each foot controller. On the front side, there are 2 push buttons for foot switches 1 and 2.

There can be two variations of this project. The basic 4 switch project has the four switches at the top of the control box which perform the functions of the foot controller. I call this the basic 4 version. The 4 + 2 version adds switches on the front of the control box for the two foot switch #1 and #2 functions.
This picture shows the clamps on the back of the box. The jaws are lined with soft foam rubber strips to prevent damage to the brace under the keys where they attach.
From the main control box, the cable goes to a small transfer box with a selector switch. The switch selects either a loop where both, push buttons as well as foot switches trigger the action, or push buttons only in cases where it wouldn't be convenient to set up foot switches. (Keyboard players who also play piano, almost always use one foot switch for the sustain function.) For the updated version and in the bill of materials and the drawings below, the switch has been eliminated and phone jacks have been used that eliminate the need for this switch.
This picture shows the whole 4 + 2 set. The foot switch jacks are connected either to the transfer box which has 2 "pigtails" going to the inlet for the foot switches, or the foot switches can be plugged directly into to the panel. Both, the foot controls and foot switch circuits are normally closed loop, action is triggered by breaking the circuit.

Many thanks to Richard Bools for providing the pin out connections for the foot controller connection to the KN5000. The wiring diagram for the foot controller is shown in the drawing to the right. Note the nonstandard pin layout order. This is also the view looking at the female receptacle on the back of the keyboard.

Basically the pins for the foot controller connector are:

1+2 controller 1
3+4 controller 3
5+6 controller 2
7+8 controller 4
Note that the foot switch contacts need to be normally closed, i.e. pressing the
switch will break the connection between the pins and activate the assigned function.
Also, you will find that if you wire up only one switch at a time it won't work, the
system relies on any one of the other 3 switches having closed contacts for the 4th to
work.
This drawing shows the cable from the controller box to a transfer box where the cable is routed to both an 8 pin DIN connector for the foot controller functions and to two phone plugs for the two foot switch functions.
This drawing shows the phone jack that maintains a closed circuit if a phone plug is not inserted and the wiring drawing for the jacks. If a foot switch phone plug is inserted in the jack, either the foot switch or the control box switch will activate the foot switch function of the keyboard. If the foot switch is not plugged into the jack, only the switch on the control box will activate the foot switch function. The transfer box shown in the photos above shows a switch in an earlier design. These phone jacks eliminate the need for that switch.
The drawing to the right shows the drilling pattern for the control box that attaches to the front of the keyboard. There are four switches mounted to the top for the foot controller functions and optionally two switches on the front for the two foot switch (#1 & #2) functions
This drawing shows the small transfer box that holds the two phone jacks for the foot switches and provides a place to separate the cable wiring for the foot switch plugs and the foot controller plug.

Following is a list of the things you will need to build the project: Part numbers and prices were taken from the Radio Shack year 2000 catalog.

Contact Milan Hruby for any questions about the project.

 

BILL OF MATERIALS

Project Enclosure 4" x 2" x 1"
 For Control Box...........270-1802..............$2.29

8 Pin DIN Plug............274-026...............$1.99

Mini Momentary Push Button Switches
NORMALLY CLOSED Set of 4
two red-two black.........275-1548..............$2.99

For Strain Relief - Cable Box Out:
Heat Shrinking Tubing.....278-1627..............$1.99
Or optionally use:
Weather Boots
for Coax Cable............278-1658..............$ .99

Cable: 8 conductor for basic 4 project - 12 conductor for 4 + 2 project, similar to Radio Shack 278-876. Need about six feet.
An old printer cable is perfect for the job.

From A Stationary Store:
Bulldog Clips #2 (set of 2).....................$2.00

FOLLOWING NEEDED FOR FOOT SWITCH FUNCTIONS:

Project Enclosure 3" x 2" x 1"
For Transfer Box..........270-1801..............$2.29

Phone Jacks (Set of 2)....274-255...............$2.49

Phone Plugs (Set of 2)....274-1536..............$2.49

Momentary Switches (Same as above but only 2 needed)