Parallel Potentiometer As Cruise Control?

[xyster]

I need a diagram showing the simplest way to wire a 5k potentiometer and a switch to a hall-effect throttle such that the pot can be switched-on for use as a cruise control without shorting or interfering with the throttle, and then switched off when braking (I'm not going to bother with connecting the switch to a brake lever). It's ok if the throttle still works simultaneously with the pot.

Sounds really easy, but unlike The Fechmaster, I can't afford to be blowing up components. And I want to make certain I'm not missing anything important.

I'm thinking one 5k pot like this:
http://tinyurl.com/2nsr2m
and one SPDT switch should do it.

I'm not sure on which wire (high side, low side, or wiper) it's best to install the switch.

 

[Mathurin]

parallel the pot to the throttle, but add the switch somewhere before or after the pot. +5 and signal on the pot, turn it as needed.

 

[safe]

By connecting a pot to the throttle in series you wouldn't really be getting a "Boost Control" circuit because in a true "Boost Control" you are still able in the right circumstances to use all the voltage available, it's just if the amps run too high the "Boost Control" forces the voltage down temporarily as a way to lower the amps.

A pot connected to the throttle in parallel is like just having a "second throttle"... cruise control... as you have said. Is that really what you want? That means that the "second throttle" NEEDS a cut off or you are riding something that is potentially dangerous. (you close the throttle, but the bike keeps going anyway)

My bike has "cruise control" it's called "full throttle". :lol:

 

[Mathurin]

 

[safe]

Okay, how about this...

You place a relay between the pot and the parallel circuit. In order to set the "cruise control" the actual throttle needs to be fully closed. You then manually set your "cruise control" and the moment you OPEN the throttle that closes the relay and shuts down the "cruise control". The only problem with this is that how would you KEEP the "cruise control" from coming back on again when you closed the throttle?

Maybe throttle activity ALWAYS closes the relay, but you have a SEPARATE button that opens the relay?

So the sequence goes:

1. Close throttle.
2. Press "Reset" Button
3. Set "Cruise Control"
4. Ride...

...

18. "Blip" open the throttle, which automatically closes the relay and ends "cruise control".
19. Close throttle.
20. Apply brakes within half a second or have a collision.

 

[xyster]

parallel the pot to the throttle, but add the switch somewhere before or after the pot. +5 and signal on the pot, turn it as needed.

So I don't need to hook up the low side wire to the pot? (What's the third lead on many pots for then?)

A pot connected to the throttle in parallel is like just having a "second throttle"... cruise control... as you have said. Is that really what you want?

Yes. I'd rather have the sexy variable current limiter of course, but this'll be good enough, and super cheap. I just want to "set it and forget it" for long road cruises when my hand gets tired after awhile. Also, this should allow a little finer control over the power when my hand is moving around due to discomfort or bumps.

That means that the "second throttle" NEEDS a cut off or you are riding something that is potentially dangerous (you close the throttle, but the bike keeps going anyway).

Hence the inclusion of a single spdt switch.

My bike has "cruise control" it's called "full throttle".

The throttle, interestingly, seems to operate in inverse to many people's brain function. One gets turned up, the other gets turned off

 

[Mathurin]

Teah, these pots have three legs, but you only use two of them that are closest to each other. If you try to use the legs at each end, it won't work.

 

[fechter]

Here's the simplest approach.
If your brake cutout switches are working, they should work on cruise also. There's a lot more fancier versions that are possible, but this is basic. It's also dangerous unless you have a pretty fail safe way to kill the motor in an emergency.

 

[xyster]

I like mathurin's circuit with just an spst switch. That way, I can give her throttle without switching off the cruise throttle, only switching it off when I need to quickly slow down.

I wasn't 100% for certain this arrangement wouldn't damage the throttle, so that's why I was thinking of using an spdt switch to disconnect the throttle whenever the cruise control pot was turned on.

 

[Mathurin]

Why is the pot connected to three leads though?
I've used one flawlessly with only +5 and signal.

 

[safe]

Try reading my "relay reset" idea... it might save a collision... the LAST thing you want is to have to take your hands off the handlebars in order to shut down your motor and brake.. a quick "blip" of the throttle triggers the relay to close and then you can shut down safely without taking your hands off the handlebars.

 

[xyster]

Ah, His Fech-ness was posting while I was replying. His Fech-ness has an spdt switch connected to the wiper, and all three leads on the pot used. What'd be the difference between this circuit and Mathurin's, besides the fact that the throttle will be off when the cruise control pot is on? Why use all three leads if just two work the same?

 

[xyster]

Try reading my "relay reset" idea... it might save a collision... the LAST thing you want is to have to take your hands off the handlebars in order to shut down your motor and brake..

I did read it. Must take more time to ingest it. My hands will not be off the handlebars as the switch and pot will be installed right next to the throttle.

 

[safe]

For those that like cartoons... you can "connect the dots" of the circuit... it would be pretty easy...

 

[fechter]

It might work except if the throttle is zero, it's trying to pull down the wiper, which will be fighting the cruise control pot. If you turn up the cruise control to compensate, I'm not sure which one will "win".
Remote chance of frying the hall in the throttle also.

 

[xyster]

Safe, can you draw me a diagram of your relay-safe cruise control switch?
Where would I get the switching voltage?

I have extra 24v relays sitting around looking for a project, but only an 80v line nearby the throttle (which feeds the lights). Suppose I could use a resistor.

But then, how does the 5v throttle switch the relay without blowing the throttle to kingdom come?

 

[safe]

But then, how does the 5v throttle switch the relay without blowing the throttle to kingdom come?

Do they make relays in small voltage sizes?

If there were such a thing as a 5V activated relay then you could make a circuit somehow... I'm thinking "what" needs to happen (for safety) first and worrying about implementation later:

1. Close throttle.
2. Press "Reset" Button
3. Set "Cruise Control"
4. Ride...

...

18. "Blip" open the throttle, which automatically closes the relay and ends "cruise control".
19. Close throttle.
20. Apply brakes within half a second or have a collision.

 

[xyster]

it would be pretty easy...

Then draw a diagram complete with connections! The major problem I have with some of your posts, Safe: you offer interesting, sometimes excellent ideas and then suggest the implementation is easy when you yourself can not describe how to implement it! Either these ideas are not so easy, or compared to your imaginative ability, you're a relative moron at putting thoughts into action (meant in the nicest way, of course ).

 

[safe]

What an idiot I am...

Okay, keep the "Reset" button, but rather than a "blip" of the throttle use the brakes to close the relay instead. That's sooooo obvious.

If you want to get right back to where you were you just press the "Reset" button or use the throttle... either way you never have to worry about stopping...

Okay.. I'll try to draw a circuit... you have to wait...

 

[xyster]

Do they make relays in small voltage sizes?

I'm thinking your idea could work with a small, latching relay. I've never used one before and don't know if they act like a push-on, push-off switch (I.E. not momentary, one blast of electricity to open, a second blast to close)

 

[Leeps]

I'm really interested in the reset button.
Joe

 

[safe]

Here's the basic concept without much real electrical knowledge to back it up. You can kind of see where I'm going, though there are errors in it still I'm sure.

Relays are triggered by a "pulse" and they like having separate wires for triggering. The "reset" just sends a "pulse" to switch the relays over to the pot. When the brake is used it automatically switches the relay back to the throttle. If you want to jump right back to where you were before (you liked that previous pot setting) then you just hit the "reset" button again and off you go back into "cruise control".

Easy... :lol:

 

[Leeps]

the schematic is well...yeah
but i see where your going, latching 5 volt relay is the key, let me see if i can find one.
Joe

 

[xyster]

For starters, the pot looks like it's wired in series with the throttle, not parallel. And it doesn't look the throttle will switch the relay like I thought you were suggesting it should. There's three wires on the throttle and pot, not two.

Anyway, I don't see how the throttle can be used to switch the pot on, without the pot switching on every time the throttle is twisted wide-open.
If it wasn't a latching relay, the pot would be turned off anytime the throttle was released, obviating the entire reason for a cruise control in the first place since one hand would always have to be on the throttle to use the cruise control! And then we'd still need a switch to turn the pot off for emergency braking. As I noted in the initial post, I'm not going to wire a switch to the brake -- at least not at first, it's probably take too much work and a regular switch should work fine since it'll sit right next to my thumb, and the left hand is still free to initiate emergency braking with the left brake. Both brake levers are connected to the front wheel anyway, so it's not like I have uber-great braking!

 

[xyster]

Leeps, if you can massage Safe's screwy "but easy" :? diagram into a schematic that'll work sensibly with a latching relay and no connections to the brakes, that'd be great! We can dedicate your cruise control circuit to the circuit library.

The last circuit Leeps helped me with, I built per his directions, but I never got to try it.