# Cruise Control



## Tesseract (Sep 27, 2008)

ewdysar said:


> Do any of the typical controllers from our regular vendors have cruise control circuits? Like something that can easily be hooked to the cruise control buttons on a car's steering wheel? It seems like an easy way to maintain constant speed which can improve range...
> 
> Eric


Regulating motor RPM is easy; how do you imagine a controller would be able to interface with any particular vehicle's cruise control buttons "easily", though?


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## few2many (Jun 23, 2009)

They have aftermarket cruise control kits that allow you to add it to any car. Very simple, straight forawrd install. Cost me about $120usd to buy and a couple hours installing myself. The car was a '77 toyota cellica.
You will need a vacuum source, unless the kits have changed to work without. They either tie into the cars distributor for a tach lead, or have a small magnetic sensor installed on the drive shaft. Also, there is a wire installed on the brake light lead.
I would leave my oem throttle pedal in place, use the cable to actuate the pot box under the hood and connect the cruise control actuator there.


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## ewdysar (Jun 15, 2010)

Tesseract said:


> Regulating motor RPM is easy; how do you imagine a controller would be able to interface with any particular vehicle's cruise control buttons "easily", though?


This was just a quick thought. For the last few days I've been trying to really pay attention, to get an idea about how I actually drive my car, how much I use the brakes, decompression, throttle etc. in an effort to get a grip on how an electric would fit in my life. It turns out I use cruise control more than I would have guessed.

Though I haven't taken any apart, they do seem to be a consistent set of switches. On/Off for the cruise control system. Cancel to drop out of speed control while keeping the system active. Set/Decel to set the speed and to reduce speed while in control mode. Resume/Accel to resume the previously cancelled speed setting and to increase speed during control mode.

I had always figured a small bundle or ribbon of wire coming from the switch set, but if they use just a pair of wires, then the encoding would invariably be different for each manufacturer. 

Realistically, on/off and set are the important controls, the rest are just convenience. 

So I guess my question is whether there is an external connection on the regularly available controllers to set/disengage a "cruise control" mode. Like regular cruise control, I would expect it to disengage automatically when the brakes are pressed.

Eric


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## few2many (Jun 23, 2009)

Yes. The brake light wire tap will shut down the cruise when the brakes are applied. The speed sensor will keep the vehicle at the measured speed, unless there is a sudden and large change in the measured speed.
The one I installed was on a 5speed manulal. So, I used the tach lead. On an automatic, you want either the vss from the transmission, or to use a driveshaft mounted sensor.


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## ewdysar (Jun 15, 2010)

few2many said:


> Yes. The brake light wire tap will shut down the cruise when the brakes are applied. The speed sensor will keep the vehicle at the measured speed, unless there is a sudden and large change in the measured speed.
> The one I installed was on a 5speed manulal. So, I used the tach lead. On an automatic, you want either the vss from the transmission, or to use a driveshaft mounted sensor.


While I'm sure that this type of system will work, it's not very elegant. See if I get this right. Add a sensor on the motor (or driveline) to create an electrical signal, convert it to mechanical movement though an independent controller and actuator, to move a mechanical sensor (throttle box) to adjust the electronic signal back to the main controller to adjust the current to the motor.

I figured that just telling the controller to maintain the speed eliminates the time lag, mechanical inaccuracies and multiple points of failure. The controllers are doing much more complex functions already, and they should already be wired to the brake circuit. This seems like a pretty simple feature set, so I'll be surprised if none of the controller designers have bothered to include it.

It's OK if none of the controllers have this added function, I was just curious. I figured that people here are much more familiar with the extra features of the various controllers than I am.

Eric


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## Qer (May 7, 2008)

ewdysar said:


> I figured that just telling the controller to maintain the speed eliminates the time lag,


A motor/controller combo reacts faster than an ICE anyway so I don't think there's a problem.



ewdysar said:


> mechanical inaccuracies


Oh, there's multitudes of those in an ordinary ICE.



ewdysar said:


> multiple points of failure.


Still not worse than in an ICE.



ewdysar said:


> The controllers are doing much more complex functions already


Uhm... Nope. They're doing a LOT of functions already, but none of them are very complex. The tachometer calculations and the idle-loop in the Soliton are probably the most complex ones, which might be why, as far as I know, the Soliton is the only controller that has an idle RPM-feature for automatic gear boxes.



ewdysar said:


> and they should already be wired to the brake circuit.


I concur, but in reality it seems it's more common they're not. We had to do that feature optional in the S1...



ewdysar said:


> This seems like a pretty simple feature set


Um. Nope. It's a friggin' pain, even if it's on my todo-list. It just doesn't have to work, it has to be stable too (so you don't get car sick) and also handle all possible fuck-ups to avoid the car getting out of control or so.



ewdysar said:


> I'll be surprised if none of the controller designers have bothered to include it.


Be surprised.


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## ewdysar (Jun 15, 2010)

Qer,

Fair enough. Of course, I would prefer to do better than an ICE car in the features where a fly-by-wire electric drive is inherently superior. There's no sense in accepting the analog limitations of mechanical systems that aren't necessary. It just seemed to me that strapping on an aftermarket cruise control setup is a little more Rube Goldberg than I would prefer.

Like I said before, it's no big deal, I was just curious.

Eric


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## Coley (Jul 26, 2007)

Actually, I thjink you can do a better job at getting the best range from your EV WITHOUT Cruise control.

On an ICE, when encountering a hill, it will bring up power to maintain the speed.

If you have driven an EV you will note that you don't want to do this unless you really have battery to spare.

It is best to just hold the rpm you are at, until you crest the hill. even losing some speed on the hill and then gain it back on the downhill side. CC will not let you speed up on the downhill side.

You can override it with your foot, but that defeats the purpose.

CC won't let you speed up a bit in anticipating a small hill.

From my driving exoperience, you don't really need or would like CC on an EV.

But that is just my .02..........


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## ewdysar (Jun 15, 2010)

Coley said:


> Actually, I thjink you can do a better job at getting the best range from your EV WITHOUT Cruise control....
> 
> But that is just my .02..........


Coley,

I agree. I know that I can do better than cruise control. I used to hypermile with my '90 Geo Metro when I bought it new. But squeezing the last few percentages out of your drive takes constant attention.

I find that if I'm not focusing on mileage, then CC definately does a better job. When I'm driving to work, or coming home, I've usually got more important things to think about. My Fit will cruise at 75mph without a complaint, I find that CC keeps me from speeding, both uphills and on the level. Especially when I want to cruise at 60mph to stretch my tank, the flow of traffic often encourages me to unconciously go faster, CC never forgets. I also use CC on surface streets to lock in on the speed limit, again it's easy to hit 50 on long runs of divided road with a 40mph limit.

So it's really just a matter of convenience. It would be nice if converting to electric didn't mean having to give up all of the creature comforts of newer cars. I know that Tesla, Leaf and Volt include cruise control in their feature list...

Eric


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## Tesseract (Sep 27, 2008)

ewdysar said:


> ... It would be nice if converting to electric didn't mean having to give up all of the creature comforts of newer cars. I know that Tesla, Leaf and Volt include cruise control in their feature list...


Comparing the automotive OEMs with those of us that make motor controllers for DIYers hardly seems fair... Ya think Tesla, Nissan and GM might have a few more engineers on staff - not to mention much deeper pockets - than Evnetics, NetGain, etc.?


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## Woodsmith (Jun 5, 2008)

I'm another for 'interesting but won't bother with it'.

I've had cruise control and the best thing I found it for was towing a trailer on the motorways at a steady 60mph to avoid speeding tickets and for the same reason where there are long stretches of average speed cameras as silly slow speeds.

The rest of the time I have the advantage of anticipating road conditions and adjusting speed and power delivery in advance to use momentum and gravity where I can. That is something CC can't do unless it is linked in to a super accurate GPS for the hills and radar for scanning the traffic ahead.


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## ewdysar (Jun 15, 2010)

Tesseract said:


> Comparing the automotive OEMs with those of us that make motor controllers for DIYers hardly seems fair... Ya think Tesla, Nissan and GM might have a few more engineers on staff - not to mention much deeper pockets - than Evnetics, NetGain, etc.?


Let me back up here. I, in no way, want to slight the incredible amount of high quality work and engineering that has been put into the various components that have been designed by people on this board. I seriously apologize if my comments sounded like any sort of put down. I shouldn't have put the references the major manufacturers in my post.

But today, the public doesn't view electric cars in a very good light. I think that building cars and showing people what can be done is a great PR channel. But much like 15 years ago, the last time I was involved with EV's, I see that many of the conversions come off as science experiments. Lots of the cars have little trunk space left or have sacrificed their back seat, little to no heat or A/C, sound deadening is stripped. The regular populace will politely acknowledge the effort and accomplishment, but in no way can see themselves driving one. I know that the conversion companies, the ones that will convert a car for a customer, often using the same components that we do, have been a fringe industry because going electric not only costs considerable money, but also means giving up some relatively basic features.

I'm not an EE, nor do I play one on TV, so I don't know how complicated a CC circuit is, although the controller portion of an aftermarket CC system doen't seem overly complex. I had thought that the mechanical interface and sensors for those systems were the hard parts.

I've gone through same evolution with other DIY cars, hot rods and engine swaps. The first priority was just to get them moving. But I now believe that until you can add a level of fit, finish and features, our projects remain a mere curiosity to people that haven't gone down the same path. 

I know that this conversation is a little conceptual and certainly subjective. And perhaps this is not the place to toss these ideas around. 

Again, I apolgize to anyone here that I might have offended with my musings and I value the opportunity to be a contributing member of this community.

Thanks,
Eric


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## 9852 (Jan 17, 2010)

well my ford explorer has CC but I along with most of the people here driving around Phoenix are not using CC, because there is a light every ten feet or a speed camera on the highway, so CC Is no tan option one would consider when buying a car(at lest in my opnion), as far as heat, many EVs have heat, and many still have ac, using the factory parts, I on the other hand are doing my ac differenty, but it can an has been done enough to consider an ev for nornal commutting with all the creature comforts. and my car as with lots of other EVs has ALL of its trunk space, and a back seat. so..........


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## 9852 (Jan 17, 2010)

I also want to add that my EV only cost $3800 bucks to date to build so its to expensive? really?


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## ewdysar (Jun 15, 2010)

billhac said:


> .... as far as heat, many EVs have heat, and many still have ac, using the factory parts, I on the other hand are doing my ac differenty, but it can an has been done enough to consider an ev for nornal commutting with all the creature comforts. and my car as with lots of other EVs has ALL of its trunk space, and a back seat. so..........


I looked at your blog and you state that you've got 300Ah of batteries in the trunk along with some of your electronics. If that is still true, I wouldn't say that you've got "ALL" of the original trunk space left. I do, however, like how you got a few batteries under the rear seat while maintaing the seatiing area. 

I like your EV, but I read that even your wife hasn't become a convert. That everyday person perception is what I was talking about and even living with a sucessful one in the family hasn't seemed to convince her.

I think that you've done a great job on your conversion, you have every right to be proud.

Eric


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## ewdysar (Jun 15, 2010)

billhac said:


> I also want to add that my EV only cost $3800 bucks to date to build so its to expensive? really?


You can see that I was referring to cars that have been converted by a conversion company. Have you seen any of those prices? 

Eric


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## Tesseract (Sep 27, 2008)

ewdysar said:


> Let me back up here. I, in no way, want to slight the incredible amount of high quality work and engineering ...


Nah, slight away... it doesn't offend me one bit, but I will think you are an ignorant and clueless sonuvabitch if you do so 



ewdysar said:


> But today, the public doesn't view electric cars in a very good light. ... I see that many of the conversions come off as science experiments.


Oddly enough, I totally agree with you. Most conversions _do_ come off as science experiments, mainly because the people are so obsessed with doing them as cheaply as possible. We sorta sidestepped that entire mentality with the Soliton1 and concentrated instead on performance (trying to compete with the Kelly's of the world is a sucker's game). 

The thing is, a conversion done well costs money or time (or, usually, some of both). You want to see some seriously nice conversions? Check out rebirthev.com. And yep, they are seriously expensive. What you seem to be conveniently ignoring here is that the EV - mainly because of the batteries - simply can't take over every task currently performed by ICE vehicles. There isn't the same level of charging infrastructure as there is for refueling ICEs. There isn't even close to the same number of OEM and aftermarket products to choose from in making an EV or conversion. These are apples to oranges comparisons.

Now, back on topic... cruise control was considered a luxury option on many vehicles until just a couple years ago, so your surprise that it isn't included in EV motor controllers is what struck me as a bit disingenuous. Sure it only requires adding lines of code to the software that, e.g., runs the Soliton1 to implement cruise control, but the code is already over 5500 lines long and that is quite an achievement for a single man (Qer) to accomplish in about 2 years while working full time at a "real job".

All that said, we were thinking of offloading cruise control into a separate box that also expanded the auxiliary I/O, so that only people that really wanted CC had to pay for it. Interfacing with the existing CC system, though, is pretty much not an option. There's just too many variations on that theme from brand to brand and even model to model within a brand. Also, we have learned the hard way that just getting a modern vehicle to still behave properly after the engine has been removed is sometimes extremely difficult. Once again, rebirthev.com has quite a bit of experience with those sorts of problems - probably more experience than they ever wanted to acquire.

Bottom line: it's not trivial, it's not easy, and the market is way too small (but that was true for motor controllers in the first place...  )


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## 9852 (Jan 17, 2010)

ewdysar said:


> I looked at your blog and you state that you've got 300Ah of batteries in the trunk along with some of your electronics. If that is still true, I wouldn't say that you've got "ALL" of the original trunk space left. I do, however, like how you got a few batteries under the rear seat while maintaing the seatiing area.
> 
> I like your EV, but I read that even your wife hasn't become a convert. That everyday person perception is what I was talking about and even living with a sucessful one in the family hasn't seemed to convince her.
> 
> ...


well, you should have noticed the dates of those post on my blog, when I first built the car, you are right, all of the batteries were in the trunk, but since then I have made battery boxex for all 12 batteries and chargers under the trunk, so now even my wife loves to use the car, for groceries, going to the mall or just what ever, however she does most of that at night, because it is a bit cooler here at night, but when my ac is finished, I may end up loosing my EV to my wife. I agree about conversion company prices, but those guys have to get paid for doing the work, the reason mine is still so cheap I mostly because i converted it myself, im not a mechanic or an EE but if I can do it so can any one. with respect to the conversion companies it is still cheaper than buying new, and you wont have to wait for it on some waiting list.


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## 9852 (Jan 17, 2010)

my piont is if you can make a very nice commutter EV with Ac And heat, then once people see it and start to drive it there perception will start to change, at least for most people.


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## ewdysar (Jun 15, 2010)

Tesseract said:


> ...Oddly enough, I totally agree with you. Most conversions _do_ come off as science experiments, mainly because the people are so obsessed with doing them as cheaply as possible. We sorta sidestepped that entire mentality with the Soliton1 and concentrated instead on performance (trying to compete with the Kelly's of the world is a sucker's game).
> 
> Now, back on topic... cruise control was considered a luxury option on many vehicles until just a couple years ago, so your surprise that it isn't included in EV motor controllers is what struck me as a bit disingenuous. Sure it only requires adding lines of code to the software that, e.g., runs the Soliton1 to implement cruise control, but the code is already over 5500 lines long and that is quite an achievement for a single man (Qer) to accomplish in about 2 years while working full time at a "real job".
> 
> ...


Tesseract,

Thanks for taking the time to write the explanation(s) in this post. I now have a better apprieciation for how much effort a CC module would be. The funny thing is that I sold my '90 Geo Metro, which I had bought new, primarily because it didn't have CC or power windows. The car was in great shape, 6 years old with 130,000 miles with no major repairs and a lifetime gas mileage average of over 52mpg. I had no idea that 20 years later, there would be zero new cars available that would deliver the same mileage. 

Like I've said in other posts, I use CC all the time, so if I do build an EV in the near future, CC is one of the features that I'll try to work out. Because I've got a full time job and a number of other hobbies, sailing (including offshore racing), blacksmithing, woodworking, medeival research, camping, etc., I don't want my conversion to be a science experiment. I want off the shelf parts and fully expect to spend $20k in the conversion, more than half would be the batteries. I'm not afraid of some general fabrication, but I don't have a thousand hours to spend dicking around with little issues. I know from working on a half dozen EV conversions back in the '90s and a few race car builds that the big issues are time consuming enough.

Anyway, thanks again for the answers. I couldn't find anything with as much value on this topic in hours of searching previous posts.

Eric


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## coulombKid (Jan 10, 2009)

ewdysar said:


> Tesseract,
> 
> Thanks for taking the time to write the explanation(s) in this post. I now have a better apprieciation for how much effort a CC module would be. The funny thing is that I sold my '90 Geo Metro, which I had bought new, primarily because it didn't have CC or power windows. The car was in great shape, 6 years old with 130,000 miles with no major repairs and a lifetime gas mileage average of over 52mpg. I had no idea that 20 years later, there would be zero new cars available that would deliver the same mileage.
> 
> ...


When I put cruise control on my 1964 pick-up I got a dirt-simple vacuum servo unit from JC Whitney. I had to put two magnets on the drive shaft and mount a pick-up coil. If you have a vacuum pump and tank for your power brakes then the vacuum-servo pull cable could be attached to your hall effect accelerator fairly easily. The rest would be all the same.


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## drgrieve (Apr 14, 2011)

An idea I picked from somewhere.

By using regen on the throttle and the in built CC module controlling a drive by wire throttle output in theory you shouldn't have to do anything and as a bonus it would be better than stock CC as you'd be kept to speed limit on downhills.

But at the moment since EV's are not usually long range cruisers CC would be a low prority feature for me.


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## charliehorse55 (Sep 23, 2011)

rebirthev.com seems to be down for me...


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## Tesseract (Sep 27, 2008)

This is an old thread and I think the site has changed since then - try http://rebirthauto.com/


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## charliehorse55 (Sep 23, 2011)

Tesseract said:


> This is an old thread and I think the site has changed since then - try http://rebirthauto.com/


I see nothing but a store. Where can I read about their experience with vehicle computer systems and the like?


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## Tesseract (Sep 27, 2008)

charliehorse55 said:


> I see nothing but a store. Where can I read about their experience with vehicle computer systems and the like?


That isn't posted to the web. Where did you get the impression that it was?


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## Jamie EV (Oct 3, 2012)

Why is it not possible to simply utillize the second cruise control servo wire and run it into the pot box along side the regular pedal cable? 

My Elantra has a servo actuated cable that opens the butterfly valve...I'm thinking that if it takes speed and throttle readings from the existing tranny, and it is able to actuate the caBLE...IT SHOULD mate to the pot box the same way as the pedal cable does.

Am I way off base on that? Might take some figuring out but it would be a shame to reinvent the wheel when the car already has it...in my case.


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## Tesseract (Sep 27, 2008)

Jamie EV said:


> Why is it not possible to simply utillize the second cruise control servo wire and run it into the pot box along side the regular pedal cable? ...


It is possible, as long as the ECU (engine control unit) is still happy after you've, you know, _yanked out the engine_... 

Also, your EV motor controller needs to use a 0-5V signal for the throttle, and the signal from the original TPS (throttle position sensor) needs to increase with the opening of the butterfly valve (often there are two channels on the TPS and sometimes one of those channels goes down as the valve is opened up - that won't give you the expected results, to put it mildly).


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## Jamie EV (Oct 3, 2012)

Tesseract said:


> It is possible, as long as the ECU (engine control unit) is still happy after you've, you know, _yanked out the engine_...
> 
> Also, your EV motor controller needs to use a 0-5V signal for the throttle, and the signal from the original TPS (throttle position sensor) needs to increase with the opening of the butterfly valve (often there are two channels on the TPS and sometimes one of those channels goes down as the valve is opened up - that won't give you the expected results, to put it mildly).


well failing that, a simple comparator circuit could be used to store the pot position and then lock it. Sort of a "sample and hold" type deal that you could hit with a button, freeze your pedal position, it would disengage the moment you hit the brakes. 

Alternatively, if you were to create an encoder wheel on the speedometer, you could create a more sophisticated logic gate that increases throttle when speed drops below the sample and throttles back when speed drops below the speedo sample....

much easier to program this on a small computer than it is to build a gate from scratch either way it's not my forte... I have programmed simple sample and hold...maybe there's a simpler way with ttl or cmos gates.


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## Tesseract (Sep 27, 2008)

Jamie EV said:


> well failing that, a simple comparator circuit could be used to store the pot position and then lock it. Sort of a "sample and hold" type deal that you could hit with a button, freeze your pedal position, it would disengage the moment you hit the brakes. ...


Modern motor controllers for EVs use the throttle to regulate torque, not speed (true for both AC and DC motors) so locking the throttle to one value would not result in a constant speed unless the torque load remained constant (ie - the grade remained the same, wind speed, didn't turn on (or off) the a/c, etc.).


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## Jamie EV (Oct 3, 2012)

Tesseract said:


> Modern motor controllers for EVs use the throttle to regulate torque, not speed (true for both AC and DC motors) so locking the throttle to one value would not result in a constant speed unless the torque load remained constant (ie - the grade remained the same, wind speed, didn't turn on (or off) the a/c, etc.).



Good point...ok then do a simple subroutine "cruise" that says :

if speedo < set-point then accelerate....else if speedo > Set-point then decelerate else if speedo=set-point then gosub cruise

I bet a simple logic gate could be constructed to do that...or a small microprocessor...


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## Jamie EV (Oct 3, 2012)

Jamie EV said:


> Good point...ok then do a simple subroutine "cruise" that says :
> 
> if speedo < set-point then accelerate....else if speedo > Set-point then decelerate else if speedo=set-point then gosub cruise
> 
> I bet a simple logic gate could be constructed to do that...or a small microprocessor...


yes I am a spaghetti programmer


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## mizlplix (May 1, 2011)

I too have installed the Audiovox add-on cruise control to several cars.

1- speed comes from VSS on transmission.
2-K/Sw signal
3-GRD
4-On/off button
5-Set button
6-Resume button



On An EV, it is even simpler.

1-A small 0-5K twist pot to set speed
2-An on switch 
3-Three small relays-
1 for throttle signal (the pot) sets speed-in parallel with foot throttle pot.
1 for duplicating the foot throttle pot switch on/off signal
1 for turning the first two relays on/off. Can be cancelled 
by #2 switch or brake signal.

You are driving on the road, you flip the "enable" switch, both the throttle on signal and the throttle speed signal are put in parallel to the existing foot throttle. You simply set the hand pot up to set your road speed.

When stopping, the brake signal will open those circuits and cancel the cruise system,(or you flip the enable switch)

Yes, it works in the flat with no hills and not a true torque throttle.

Miz


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## Jamie EV (Oct 3, 2012)

mizlplix said:


> I too have installed the Audiovox add-on cruise control to several cars.
> 
> 1- speed comes from VSS on transmission.
> 2-K/Sw signal
> ...



But I bet for most of us it would still work well...just be careful on the downhills...


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## BrownBageV (Nov 10, 2011)

Any other aftermarket cruise control systems that you can recommend for EVs?
So far we have:
Audiovox CCS100 Universal Vacuum Cruise Control
Rostra Universal Electronic Cruise Control 250


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## jenkinskg (Nov 4, 2017)

I just bought a old school universal cruise control.
Has magnets etc to sense speed, going to try and add it to my 2013 smart fortwo, I think my cars brain has one built in, but not sure how to make it go.
Other models seem to have the buttons/feature


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