| Author | Message | ||
     Peter |
The Dakar KTM has a switch for operating the roadbook. It has a reputation for breaking if the bike is dropped, or if it gets hit by a knee, so I figured I'd replace it with a Touratech version. Problem is, the KTM bike has a routesheet holder that uses one electric motor. The switch changes it's direction by reversing the polarity to the motor. The Touratech version has two motors. It's switch has three wires. One providing power in, and the switch sending power via one of the other two, to either motor. Is there an easy way to use the Touratech switch on the KTM's routesheet holder? I don't want it to get complicated by using relays etc, although I could live with diodes if need be. Any ideas, or have I just outsmarted myself? | ||
| Glitch |
Opto is good with electrics. PM him if he doesn't chime in. | ||
| Natexlh1000 |
I know how to wire a toggle switch to reverse polarity. Let me get busy with MSpaint... | ||
| Natexlh1000 |
OK I tested it out to make sure I got it right...  OK that is a DPDT (dual point, dual throw). The best kind of switch to get would be one with a "neutral position" in the middle so that it is effectively off. See the way it works? put the input to the RED BLUE set and the brown ones will be your switched output. The purple/green wires are of course not touching in the middle where they cross  | ||
| Peter |
That's what's on there now. What I want to do is replace it with one of these.  | ||
| Oldog |
peter: do you know how to test electrical switches for on off, I get the feeling that the buttons are "Momentary" meaning off until pushed, off when released. Tiny relays actualy make some sense although they add weight and complexity enclosed and potted properly should not be any trouble this is the touratech?  I know that you don't want to do relays but this is a positive isolation so you dont short out the wiring by having F&R on at the same time there are some realy small relays on the market too. the ones in the pix are DPDT [ double pole double throw ] like the ktm switch diodes prolly wont work reliably  When the Up button is pressed the R1 relay is activated IF R2 is Not activated, causing Am to be the + pole, and Bm to be the - when released the R1 turns off the power to the motor is off, when Down is pressed R2 activates and IF R1 is off then Am is - and Bm is + The button assy needs 4 wires to work or needs to be as nate drew with out relays, IF you do not interlock the setup you could be asking for trouble, IF the tourtech is mechanicaly or electricaly interlocked in side the switch housing then you can have the 3 wire setup  I shudder to think of a short in the setup in the desert peter I hope that this helps, Good luck. | ||
| Peter |
Jim, Thanks for the schematics. I just checked the switches. They are momentary. It has three wires, and no interlock in the switch block. I can feed a circuit out each wire if both buttons are pushed. Any more ideas? | ||
| Pilot |
Pete check email. | ||
| 99x1 |
A diode could replace one of the relays in the above circuit - when the Down button is pressed the relay coil will not be powered due to the diode, and the motor will be activated through the normally closed contacts of the relay. When UP is pressed, the relay is energized, and the normally open contacts then reverse the motor. The diode could be soldered at the relay pins, and would have to be sized big enough to carry motor current. If both buttons were pushed, the Up circuit would operate.  (Geez, I'm no artist - I can't even draw a straight line on a computer!) | ||
| 99x1 |
The circuit for reversing a DC motor is called an "H-Bridge". Theory at H-Bridge Theory. A solid state H-bridge mounted in a epoxy filled enclosure should be fairly rugged? | ||
| Oldog |
John: Thanks for resopnding haven't heard much from you lately, I am not familiar with the H bridge, looks a lot simpler for sure, and safe too as up is given presidence over down if both switches are pressed. Pete after looking at the wiring the 3 wire could be done as well with a tweek with 2 relays. Choices choices ... how ever you go - good luck | ||
| Peter |
Thanks for your input guys. Pilot has sent me a diagram using two relays, that looks to be short proof and better for me, idiot proof as well. I'll give it a try just see if it is indeed idiot proof!  | ||
| Firemanjim |
My head hurts---- Thank goodness they weren't colorcoded or I'd really be hurting. I used to just be colorblind,now since ADA,I'm disabled and a "protected class".LOL. | ||
| 99x1 |
Got thinking today of a module that would switch using the flash-to-pass headlamp switch might be usefull. The only time both hi and lo beams are on is when this switch is pressed. The module would plug in with a male and female headlamp socket (to make easy install / removal), sense HI and LO beam, and pull in a relay when the pass-to-flash was pressed, release if it was pressed again. Using cheap logic controls (like a MicroChip 12F683 <$3), it could using timing - ie one quick press would be a forward function, and two quick presses would do a reverse function. Not sure if a Dakar KTM would have a flash-to-pass switch.... | ||
| Bomber |
FMJ -- it's a shame that thickheadedness isn't a protected class -- I'd be swthed in cotton batting! this thing is more my level of understanding  | ||
| Tom_b |
Don't know about being an electrical whiz, but know better than to whizz on an electric fence!  |
