Open source waterproof ignition switch, ideas?

[spinningmagnets]

I'm sure I will say some of this wrong, please be patient as I am weak on electronics.

Ive noticed that a lot of generic ebike controllers have an ignition wire - set that needs to be plugged into itself if you don't want to add a conventional on/off switch. I assume it uses a 5V signal, and the circuit is energized at low amps to tell the controller to turn on.

My wife once had a treadmill that I assembled. It had a long wrist lanyard with a weak magnet which was placed onto a spot on the control panel to get it to work. If you fell when the treadmill was running, the magnet was easily pulled off and the treadmill would stop.

If a fully potted hall sensor had a piece of steel potted next to it, a simple ferrite refrigerator magnet could become an on/off switch, and if a real key was desired...a hinged panel could cover it which would be locked by a common file-cabinet lock. If the key is lost, such a panel - lock could be easily removed and replaced.

Such a device would not be a comprehensive anti theft deterrent, but bikes can be carried off by hand. I personally believe the theft tracking system should be sophisticated (GPS?), and any on/off switch should only deter a small child from activating the hand-throttle or PAS pedal.

I am after a level of water-proofing in that can operate underwater with absolute confidence...

 

[bowlofsalad]

I am skeptical I understand your vision concerning the hall sensor switch.

However, I think that with your opinion of a keyed switch being largely worthless, perhaps simply a waterproof switch mildly hidden would serve the same purpose and easily achieve the results you desire while saving you having to mess about with a key. http://www.amazon.com/gp/product/B0022ZV1KE/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0022ZV1KE&linkCode=as2&tag=xbnijgbr-20&linkId=T75BJAA7QIXWZEYO

Perhaps instead of a switch you could simply add connectors to each end of the ignition [strike]switch[/strike] wires, plug for on, unplug for off, a little dielectric grease in the connectors and some heatshrink on the back.

The idea behind a waterproof connection is, so far as I know, to where it involves several connectors in close proximity to each other. The issue is moisture acts as an electrical bridge and then the various connectors become shorted to one another, which can obviously be insanely undesirable in scenarios where you have a bunch of hall wires(for example) directly beside one another. The ignition switch isn't going to have anything immediately beside it, it is basically shorting to itself, the need for waterproofing in the scenario becomes pretty insignificant. To put this more clearly, your ignition switch remaining connected or in the on position isn't likely to be effected by being submerged in water, so basically any singular plug or switch used for ignition can probably be used with absolute confidence. What you don't want is corrosion, which something like a little dielectric grease and plated connectors should do great with for a very long time, but even just that switch might work great for a really super long time.

As always, if you are concerned with waterproofing things like drip loops and fenders will help immensely without the need for very high end waterproof connections. The spray that comes off of a tire at speed can be both high pressure (can penetrate water resistant and some water proofing setups) and exceptionally conductive/corrosive. So, to me, waterproofing starts with fenders.

With just a little comprehension of how ignition switches work, obviously anyone with 30 seconds (or less) and some wire strippers will see the keyed switch as a tell as to which wires to cut, strip and twist together (I could do it in 15 seconds) to attain ignition. I know of no other controller that has this, but adaptto controllers comes with the ability to add a password to operate the e-bike. I agree though that the GPS notion is probably the wisest if you are worried your several $100 ebike is going to get hauled away by two guys with an old pickup truck and a few fast and relatively cheap tools that would turn the majority of locks into dust in the wind within seconds.

 

[amberwolf]

Ive noticed that a lot of generic ebike controllers have an ignition wire - set that needs to be plugged into itself if you don't want to add a conventional on/off switch. I assume it uses a 5V signal, and the circuit is energized at low amps to tell the controller to turn on.

All of the ones I have used (and read about in ES threads) that have "ignition" wire is full battery voltage. The wire is simply the connection from battery to the input of the low-voltage-regulator system that powers the MCU and drive circuitry, as well as throttles, hall sensors, etc. The regular battery wire (thicker one) is what goes to the FET power side. So the system can be left connected to battery all the time, and the igniton just cuts power to the brain.

It is low current, though, so it doesnt' take much of a switch to deal with it.

You could easily modify a controller to have the regular ignition always on, hardwired, but use a 5v-level signal to hold the MCU in reset state or something, but it would be easier to simply have the hall-controlled switch be in parallel (or series, depending on design) with the ebrake lever switch, so taht it cuts or engages the ebrake line, which also effectively disables the bike.

Optionally, you could have it cut or engage the power to the throttle, to do the same thing.


As for waterproofing, there are a number of IP-something-number level switches you can buy that would be dunkable up to so-many-meters depth of water.

However, the controllers and whatnot (other than the Grin/ASI potted ones, and other potted types) and the motors themselves are not typically submersible, and neither are the batteries.

My wife once had a treadmill that I assembled. It had a long wrist lanyard with a weak magnet which was placed onto a spot on the control panel to get it to work. If you fell when the treadmill was running, the magnet was easily pulled off and the treadmill would stop.


If a fully potted hall sensor had a piece of steel potted next to it, a simple ferrite refrigerator magnet could become an on/off switch, and if a real key was desired...a hinged panel could cover it which would be locked by a common file-cabinet lock. If the key is lost, such a panel - lock could be easily removed and replaced.

You couldn't use a typical ebike-motor or ebrake hall sensor directly for this, as it would need a lower voltage power source built into it to run off the battery power, but you *could* use a reed switch, like those in the Grin Tech CA speed sensors. Most likley that would work at least up to the 60v or so that many ebikes run at. Maybe higher, but the higher you go, the more risk of arcing there is, and the larger the distance needs to be between the contacts to start with in "off" positions


Another issue with mechanical switches like that is they can bounce from vibration, even with the magnet "holding' the contacts in place, if the vibrations are severe enough. If that happens a lot during operation, I don't know how a particular controller will react to being powered on and off and on and off repeatedly like that. :/


A further issue with a hall sensor is that you need a certain amount of magnetic field to trigger it, dependign on it's design, so you need to pick a hall sensor that will trigger on the specific magnet you want to use, if it'snot a very strong one, and in the orientation you want it to trigger in.

Some hall sensors are latching output as well, so to change states you swipe the magnet across it, then to change states again you swipe it again. That might or might not be desirable; it would aid in high-vibration riding environments because the key would not have to stay on the bike during a ride; just swipe it on teh sensor andit turns on, then when done swipe it again and it turns off.



FWIW, Agniusm, I think it was, has a thread about switch design that uses fingerprint reading, IIRC. The same switch could be used without that kind of complication, using a different input to drive it, if he's got that part of the circuit posted. If not, Methods may have posted his switch design up, somewhere in one of the LVC/BMS threads of his system.



All that said, it'd be more "safe" and theft-deterrent if you install a jumper connector for the battery connection that prevents use without it. Sure, someone could short across the terminals, but they'd need to know where it is and what to do--to most it would look like a connector to plug something into, not to jumper across, and when it sparks as they short across it they may well just leave the damn thing alone.


I'd use an Anderson SB50 type, as they are designed to be very easy to panel mount with screws, and to tie a pull-tab or string to exactly for this purpose (it's done with a number of powerchairs, forklifts, golf carts, etc, for servicing safety among other things).

It's already been done here on ES with various connectors. I forget who did it with a pair of Anderson PP45s, a few years back, but he still has his bike that way AFAIK.

 

[spinningmagnets]

Thank you both for the thoughtful replies. I have a lot to study up on.

 

[marty]

Look here:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=22749&p=331990&hilit=Deans+plug+shorting+link#p331990
and
https://endless-sphere.com/forums/viewtopic.php?f=2&t=23453&p=343039&hilit=Deans+plug+shorting+link#p342916

 

[Harold in CR]

When we were diving for sunken logs, in black water, we used a side scan sonar unit to try to locate logs. It had a magnetic switch on the "Fish". We would slide a magnet over the area where the switch was located on the fish, and then, lower the fish into the water. We constantly banged the bottom, hit logs, got tangled in limby trees that were sunken, and other bumps and jolts. Never had it shut off on it's own.

It maybe could be mounted inside a handle bar where it would be well protected. I would browse Digi-key or somewhere like that.

 

[Marin]

Amberwolf your well explained post gave me a great idea for my bike switch. I've already bought one of those 48v snowmobile switches but it's too big really so I haven't installed it. After reading your post I realize that I can do a switch easily as I have a magic pie kit with 2 brake switch wires. I only use one so I could wire the other one to a switch. The battery would stay connected but the throttle wouldn't work.
Or I could put an elastic band on the other brake lever with the cut off switch. I wonder how much battery power I'd loose leaving the led on all the time.

 

[d8veh]

You can use a reed switch and a magnet. I did that on one of my bikes. The one I used was a window switch from a burglar alarm, but you can use any encapsulated one that's not too small. You can find them on Ebay if you search for "Window reed switch" - about $2. A small disc magnet is better than the provided one because it will stick to it and switch it on. Stick a spare one somewhere else on the bike in case you lose your normal one.

The ignition wire carries the full battery voltage.

 

[spinningmagnets]

Thank you all so much for taking the time to reply. This has provided me with the starting info to actually buy parts and begin experiments. It may take a month or two, but I am definitely going to do something with this. If anyone has more info that is not posted here yet, please include it. I will definitely take pics and post my mistakes and successes.