Recently, I saw a product which uses four grip switches and a switching module intended to replace the standard left side switches. A good idea, but IMO the switches would be prone to inadvertant operation, and with the switch housing gone there is a long stretch of bare handlebar showing between the grip and the clutch lever perch. My design addresses these problems using sealed pushbuttons in a much smaller housing than stock.
First, the button: about ten years ago a diver had a non pressure compensated housing for a digital camera, but was having difficulty keeping the housing sealed around the shutter switch. He was grousing about it when I suggested a 6mm tactile switch shoved inside a brake bleeder cap and sealed with industrial thermal adhesive, then epoxied to the housing. When I got it rigged he tested it to 250 feet and it did not leak at all. For the math challenged that's just under 125 PSI in salt water. 10 years later it is still in service and has no problems.
Fast forward to now and that is the same principle I used for the switch, in this case intended to be mounted to the front of the stock left switch housing and pushed by the index finger. I also updated the rubber cap to one I accidentally found online that fits the tactile switch much better. Frankly I forget what the cap was originally for, but as long as I have a source I'll continue to use them.
Single switch 3.jpg
Next the switch housing: I want to control the headlight high / low (one button), turn signal left / right (two buttons), and horn (one) with the button locations more ergonomic than the conventional setup. The question is how to make it? The answer came when my granddaughter was visiting, and we went to a craft store for whatever she wanted, and right in front of me was the solution -- Fimo oven fired clay. Layering and carving it on a scrap piece of 7/8ths tubing over a very intermittent week resulted in this:
Switch housing 1.jpgHandlebar mounted 1.jpg
The second image is taken from what will be underneath the bar, and both of the turn signal buttons and horn button are activated by the thumb, while the dimmer is at the front and selected with the index finger, thus:
Handlebar mounted ergos.jpg
The positioning is preliminary, but close to what I think will work.
The switching module: I'm keeping specifics of the nature of the circuit under my hat for the moment, at least until the provisional patent process is underway. Suffice it to say the circuit design is finalized, parts are spec’d out, and board designed.
As to function:
-- The headlight dimmer is a toggle type which one push of the button will toggle between low and high beams.
-- The turn signal buttons individually toggle that side on or off, and a push of the other side switch will cancel the one side and activate the other. So far no hazard switch implemented, but if the demand is there ...
-- The horn button is a simple relatively direct driver for the transistor, no fancy electronics involved. It has sufficient capacity to drive two horns directly, or can pick up a relay for air horns.
All switching is done by P channel MOSFET transistors with an Rds
(on resistance) of 0.01 ohm, meaning there is little heat generated in operation. Thus far I can reliably switch as much as 250 watts resistive per function, and 200 watts inductive with the necessary bypass diode across the motor. Of course the current capacity can be adjusted up or down to suit applications by using different transistors.
Using surface mount components the total size of the module will be 20mm x 55mm x 8mm, exceptionally small for the current being switched, and will be fully encapsulated for environmental protection.
If I can source the connectors for the stock 919 left side switch assembly I could make it plug and play, but it would not be a problem to hard wire it in, just more time consuming.
I'll let you know when initial field testing of a prototype unit is underway.