# Magnet operated kill switch?

**URL:** https://foil.zone/t/magnet-operated-kill-switch/15715
**Category:** Electronics (ESC, remote, batteries)
**Created:** [May 14, 2022, 5:14pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715 "2022-05-14T17:14:50Z")
**Posts on this page:** 20
**Page:** 1

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### Author: ![ScotY](https://foil.zone/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@ScotY](https://foil.zone/u/ScotY)
#### Post date: [May 14, 2022, 5:14pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/1 "2022-05-14T17:14:50Z")

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Does anyone know of an off the shelf or DIY method to make a high current kill switch? I found this thread:

> [@Installing a Kill Switch](https://foil.zone/t/installing-a-kill-switch/2712/16):
>
> I use an albright relay to cut the power around 2kW, used it several times for a vesc 4.12 when it was failing to cut power with an enertion nano-x. [Nano-X with VESC provides full gas permanently - Electronics (ESC, remote, batteries) - FOIL.zone](http://efoil.builders/t/nano-x-with-vesc-provides-full-gas-permanently/2195) The vesc shuts down without damage so far. From developers view it is a normal situation. Of course you should not cut the motor, always only the powersupply. I think you should be able to cut the battery power from esc actively in some way regularly…

and there is some info, but I don’t understand the schematic posted.

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### Author: ![SoEFoil](https://foil.zone/user_avatar/foil.zone/soefoil/32/55_2.png) [@SoEFoil](https://foil.zone/u/SoEFoil)
#### Post date: [May 14, 2022, 6:41pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/2 "2022-05-14T18:41:31Z")

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You could use @jeffM’s v4 design using a Kilovac relay:

 ![schematics V4](https://foil.zone/uploads/default/original/3X/b/e/beac762858c462f2071ed62c7d630591ea1c58ad.jpeg)

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### Author: ![heddan99](https://foil.zone/letter_avatar_proxy/v4/letter/h/b2d939/32.png) [@heddan99](https://foil.zone/u/heddan99)
#### Post date: [May 14, 2022, 7:33pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/3 "2022-05-14T19:33:42Z")

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If you have a vesc, you can maybe try and use the kill switch feature in sw they introduced last year instead?  
I haven’t tested it yet, but planing to test it in the summer on one of my board to start with.

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### Author: ![sat\_be](https://foil.zone/user_avatar/foil.zone/sat_be/32/35523_2.png) [@sat\_be](https://foil.zone/u/sat_be)
#### Post date: [May 14, 2022, 8:35pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/4 "2022-05-14T20:35:42Z")

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That would be bether than to cut the battery connection and you don’t need a heavy relay.

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### Author: ![ScotY](https://foil.zone/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@ScotY](https://foil.zone/u/ScotY)
#### Post date: [May 14, 2022, 8:48pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/5 "2022-05-14T20:48:07Z")

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Thank you, guys. I didn’t realize the VESC had a built in kill switch. It’s appealing to try since it is easy but I do think a direct battery disconnection is safer overall.

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### Author: ![SoEFoil](https://foil.zone/user_avatar/foil.zone/soefoil/32/55_2.png) [@SoEFoil](https://foil.zone/u/SoEFoil)
#### Post date: [May 14, 2022, 11:22pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/6 "2022-05-14T23:22:29Z")

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The built-in kill switch feature has been implemented and tested on esk8, remains to be tested on efoils:  
**App Settings \>\> General. You can choose PPM low, PPM high, ADC 2 low, ADC2 high.**

How to enable kill switch support on Firmware 5.03  
[https://vesc-project.com/node/3426](https://vesc-project.com/node/3426)

Lanyard kill switch:  
[https://vesc-project.com/node/3356](https://vesc-project.com/node/3356)

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### Author: ![NDH](https://foil.zone/letter_avatar_proxy/v4/letter/n/54ee81/32.png) [@NDH](https://foil.zone/u/NDH)
#### Post date: [May 15, 2022, 10:58pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/7 "2022-05-15T22:58:28Z")

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I placed an switch between the BEC and the receiver and water pump. This switch is just touching the bottom of the lid when it is on tight, Rider weight Flexes the lid, pushes the switch and connects the receiver. If you fall off it takes 1 second for the receiver to drop signal to the ESC and everything stops. It seems to work well so far. It also keep the water pump from running unless it is in the water and weighted.

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### Author: ![DanDyse](https://foil.zone/user_avatar/foil.zone/dandyse/32/24709_2.png) [@DanDyse](https://foil.zone/u/DanDyse)
#### Post date: [July 16, 2022, 6:31am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/8 "2022-07-16T06:31:21Z")

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@NDH sounds very interesting. do you have any details / pictures of that?

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### Author: ![SoEFoil](https://foil.zone/user_avatar/foil.zone/soefoil/32/55_2.png) [@SoEFoil](https://foil.zone/u/SoEFoil)
#### Post date: [July 26, 2022, 8:41am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/9 "2022-07-26T08:41:42Z")

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> [@NDH](#):
>
> Rider weight Flexes the lid, pushes the switch and connects the receiver

Nice. It means that your micro switch doesn’t need to be waterproof. Interested to see your setup too 😉  
Waterproof micro switched do exist though like:  
[https://www.chinaweipeng.com/waterproof-micro-switch/](https://www.chinaweipeng.com/waterproof-micro-switch/) “only” IP67. Would they resist to a sea use ?

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### Author: ![FoilEngineer](https://foil.zone/letter_avatar_proxy/v4/letter/f/898d66/32.png) [@FoilEngineer](https://foil.zone/u/FoilEngineer)
#### Post date: [July 27, 2022, 1:39am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/10 "2022-07-27T01:39:32Z")

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Got a magnetic kill switch up and running yesterday and it works very well.

Only issue I see is if you happen to have your throttle pushed at the time you put the magnet back on it jumps straight back to that throttle setting instead of you have to zero the throttle before you can throttle up again.

I know you can set that just have not found it when the speed is done through the UART with VESC remote.

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### Author: ![ScotY](https://foil.zone/letter_avatar_proxy/v4/letter/s/e36b37/32.png) [@ScotY](https://foil.zone/u/ScotY)
#### Post date: [July 27, 2022, 2:04am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/11 "2022-07-27T02:04:53Z")

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Can you show how you made the magnetic kill switch?

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### Author: ![FoilEngineer](https://foil.zone/letter_avatar_proxy/v4/letter/f/898d66/32.png) [@FoilEngineer](https://foil.zone/u/FoilEngineer)
#### Post date: [July 27, 2022, 2:50am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/12 "2022-07-27T02:50:36Z")

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all you need is a magnetic hall effect module, power it from the UART port with 3.3v and connect the digital output to the ADC2.

Then in the VESC tool go to App Settings, General and under the General Tab you see the last row is labeled kill stitch, and select mode ADC2 High

Then when a magnet is near the hall it turn the output to the motor on and when the magnet is taken away it kills the motor

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<div class="post-metadata">

### Author: ![SoEFoil](https://foil.zone/user_avatar/foil.zone/soefoil/32/55_2.png) [@SoEFoil](https://foil.zone/u/SoEFoil)
#### Post date: [July 27, 2022, 8:54am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/13 "2022-07-27T08:54:20Z")

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You seem to be the first forum member to implement the VESC kill switch feature on an efoil.  
Do you still keep a disconnection mean between battery and ESC ?  
You’ve chosen ADC2 with a 3.3V detection. Would it work equally with PPM High same wiring ?  
On the 3356 post given above, when choosing LOW, PPM is grounded when a normally open regular ice lanyard is pulled off.

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### Author: ![DanDyse](https://foil.zone/user_avatar/foil.zone/dandyse/32/24709_2.png) [@DanDyse](https://foil.zone/u/DanDyse)
#### Post date: [July 27, 2022, 9:28am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/14 "2022-07-27T09:28:10Z")

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And are you talking about the Flipsky 75200 here?

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### Author: ![sat\_be](https://foil.zone/user_avatar/foil.zone/sat_be/32/35523_2.png) [@sat\_be](https://foil.zone/u/sat_be)
#### Post date: [July 27, 2022, 10:19am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/15 "2022-07-27T10:19:20Z")

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The kill switch feature signals the VESC to stop the motor, no power will be interrupted. PPM signal will just be ignored as long as the kill signal is active. It requires VESC FW5.3

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### Author: ![FoilEngineer](https://foil.zone/letter_avatar_proxy/v4/letter/f/898d66/32.png) [@FoilEngineer](https://foil.zone/u/FoilEngineer)
#### Post date: [July 28, 2022, 12:02am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/16 "2022-07-28T00:02:12Z")

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Its only blocking the throttle signal as a kill function so there is still power coming in.

The way to get that done is to add a relay to the main battery terminal or if you have your battery running through a bms to do it that way.

It really depends why you need the kill switch.

Keep in mind with a remote if you fall off and the remote is far enough away to loose signal and you forget to take your finger off the throttle it still cuts out the motor based in loosing signal to the VESC. So by adding a kill you have 2 forms of protection from runaway if you fall off, and effectively 3 if you consider the throttle is snap back to

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### Author: ![SoEFoil](https://foil.zone/user_avatar/foil.zone/soefoil/32/55_2.png) [@SoEFoil](https://foil.zone/u/SoEFoil)
#### Post date: [August 14, 2022, 9:12pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/17 "2022-08-14T21:12:47Z")

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> [@FoilEngineer](#):
>
> all you need is a magnetic hall effect module, power it from the UART port with 3.3v and connect the digital output to the ADC2.

Would do it this way with ADC1 set to HIGH in the Flipsky FSESC 75200 n°7 COM connector?

 ![image](https://foil.zone/uploads/default/original/3X/f/7/f7a86191b2e552e6c8df12cfc7ca87240e4ecbbe.png)

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### Author: ![jeffM](https://foil.zone/user_avatar/foil.zone/jeffm/32/82_2.png) [@jeffM](https://foil.zone/u/jeffM)
#### Post date: [October 3, 2022, 5:36pm UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/18 "2022-10-03T17:36:56Z")

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My feedback after a lot of tests.

My magnetic switch is connected on 3.3V and ADC2 and my firmware is 5.3 on my VESC maytech  
I tested ADC2 High on VESC tool but didn’t work, the motor runs even with the switch open.  
I tested ADC2 LOW, it works but not all the time  
you can see how it works on my youtube video

Maybe the problem is that I don’t use a magnetic hall effect module

[![](https://img.youtube.com/vi/ndcWU8A6zHw/maxresdefault.jpg "test kill switch VESC ADC2 low (fail)") ](https://www.youtube.com/watch?v=ndcWU8A6zHw)

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### Author: ![Larsb](https://foil.zone/user_avatar/foil.zone/larsb/32/31021_2.png) [@Larsb](https://foil.zone/u/Larsb)
#### Post date: [October 4, 2022, 5:49am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/19 "2022-10-04T05:49:50Z")

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Do you use a reed switch? I tried the same with my esc and a reed and it didn’t work reliably, the reed was not consistent. Can’t understand why though as they are used in many other applications.

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### Author: ![pablo\_foil](https://foil.zone/letter_avatar_proxy/v4/letter/p/5fc32e/32.png) [@pablo\_foil](https://foil.zone/u/pablo_foil)
#### Post date: [October 4, 2022, 7:44am UTC](https://foil.zone/t/magnet-operated-kill-switch/15715/20 "2022-10-04T07:44:23Z")

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Perhaps the reed became magnetized?  
I ve been used a big reed swtich and so far it has worked consistently

[Next page](https://foil.zone/t/magnet-operated-kill-switch/15715.md?page=2)
