would it hurt to short 2 phase wires for anti theft protecti

[nicobie]

I was thinking if I used small gauge wire and/or a 1a fuse with a hidden switch to short out 2 of the motors phase wires when parked for a form of anti-theft protection, would it hurt the controller if I forgot to switch the hidden switch off when I resumed riding the bike? I figure the wire would melt or the fuse would pop and not harm the controller (maybe).

As my bike weighs about 85 lb it would be hard to carry very far and I know when I fried my motor I wasn't able to pedal it for more than a block. :x

This seems like a simple enough thing to do.

 

[ZOMGVTEK]

The 1A fuse wouldn't provide much anti-theft protection. However, physically shorting a phase with wire would do the trick. Infenion's have this feature built in, as well as some random other controllers.

It SHOULDNT hurt the controller, it should just see the phase is shorted, and simply not do a thing. Every controller I ever used has some sort of shorted phase protection, but some may not.

I became quite accustomed to carrying heavy bikes, and my bike is currently 72 Lbs, which I consider very light. My old build was about 112 lbs, and it still could be picked up and dumped into a vehicle with a single person. This would only really protect you from someone who has no idea they can simply disconnect the motor, AND is pushing it.

 

[grindz145]

It can work if you short them, but if you keep them that way and you run the controller, it won't like it much. You'll probably burn up the controller unless you have something stupid beefy.

 

[Ricky_nz]

When I fried my GM magic controller (basically same effect as shorted phases) you could still pedal the bike if you dropped down a gear. not fast but it woulden't stop you completely.

When the controllers implement a security feature they may not be just shorting the phases but applying power to activly stop the motor when motion is detected.

unless your controller is well designed you will probably blow fets.
Yes a motor turning slowley will blow that 1 amp fuse easially.

 

[liveforphysics]

If you remembered and turned it off each time before you road it shouldn't be a problem. If you forgot, I foresee controller smoke.

 

[auraslip]

Hal has a system of relays setup to short all three phase wires together and the best part is he uses a RF transmitter so it automatically unlocks when he gets near it! frocking bad ass!!!!

Of course his method uses the battery pack to power the relays so if he lost power the relays would close and lock the wheel. He might of changed it to use latching relays so the risk of accidental wheel lock is less...

But yeah... I'm suprised less people have played with the anti-theft feature built into the controllers. I'm getting ready to set that up on my new bike.

[youtube]WhtQ7G-qPe4[/youtube]

 

[nicobie]

Thanks guys,I thought it might hurt the controller if I forgot to switch it off.

I think I'll pass on the idea.

 

[dogman dan]

Use the plug from the controller to the motor as your switch. Make a jumper plug to fit your motor wiring. When locking the bike, unplug the motor and pop in the plug that shorts the motor. Pretty hard to forget to switch it off, if it won't run till you plug back in.

In the USA, a lotta bike thieves have that truck or van real close by though. They park by the university, and steal 6-7 bikes at a time. No big deal to leave one wheel on the bike rack to them with that truck so close. They grab a wheel to go on the bike elsewhere easy enough.

The shorted phase wires would be good enough though, if you were inside a shop and could see the bike as it left. Then you could run fast enough. Be funny too, watching that fxxx try to pedal away going WTF?

Some of my bikes have a short extention needed from the battery to controller. Take that and at least he can't motor away.

 

[auraslip]

Good tip dogman. No matter how secure it is, unless you have an unbreakable lock, thieves can just throw it in a truck.

When I run into stores, I take the key with me and leave the bike in the highest gear. No way they can pedal like that!

 

[dogman dan]

One nice thing about a longtail ala dayglow avenger. My frankenbike weighs so much I haven't weighed it. I cannot pick it up easily, so nobody tossing that beast into a truck. Or wanting to. :lol:

 

[nicobie]

In a message to Edward Lyen about repairing a poofed controller he mentioned that he could enable a feature in his Infineon controllers that would LOCK the motor.

Now that's the ticket. With the front forks and wheel chained to something and a "D" lock through the rear wheel stays and wheel and with the motor locked tight and bike weighing ~85 lb., It would take a while for somebody to steal the thing.

 

[amberwolf]

Just remember that the Lock feature means the controller is on and running the whole time, and is actively applying power to the motor to fight any wheel movement when in the Lock mode.


One way I have considered making a lock wheel feature for my bike is using a giant toggle switch with a flip cap. The switch would be On Off On type, with 3 poles (one for each phase). Controller is wired to one set of On contacts, and motor is wired to common. Other set of On contacts are simply bridged across each other, shorting all three phases when it is switched to that.

Because it is On Off On, it disconnects the controller before applying the short, and vice-versa, and also has the Off mode in the middle for totally disconnecting the motor from anything--if there is a blown FET in teh controller someday, I would not have to unplug the motor from the controller, just flip the switch to Off.

The flip cap, when down, would automatically force the switch into the On-Controller position, so I can't forget which mode I'm in.

If I put the switch inside the metal casing of the bike, under a locking panel, then it's secure enough.

Of course, someone knowledgeable enough can still just cut the motor phase wires on the fork leg, but I cant' do much about that unless I use a metal covering over all the tubing the wiring loom goes over (which i've considered).

The only issue is finding a switch that can handle the phase currents; I think I have one that will work, but have to get time to try it out.