Using Reed Switches to Disable the Controller on a Trike

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rscamp   1 kW

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Using Reed Switches to Disable the Controller on a Trike

Post by rscamp » Mar 13 2010 5:06pm

Thanks to getting the idea from others here on the sphere, I recently wasted several hours experimenting with using reed switches to disable throttle on my trike. I ended up getting some small NO reed switches from DigiKey and making some small brackets and a lever arm out of aluminum to swing a small magnet toward/away from the switches to activate them. This seems to work very well with the Sturmey Archer drum brake setup.

Both the left and right sides are done the same way and the switches wired in parallel for a logical OR to disable the throttle on contact closure.

Here's a link to a short clip showing operation.

http://www.youtube.com/watch?v=JdtFGaINz_c

Maybe this will help someone else with a similar type of brakes or maybe someone has a better approach...
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Rob
Trice QNT with Astro 3215 8T & V4 Drive
Trice Q with Bafang BBS02 at 48V with "500W" limit
Astro 3210-12T + Neugart PLQE60 20:1 Chain-Puller Spring '17

Scorefield   10 W

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Re: Using Reed Switches to Disable the Controller on a Trike

Post by Scorefield » Mar 13 2010 6:29pm

:D

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rkosiorek   1 MW

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Re: Using Reed Switches to Disable the Controller on a Trike

Post by rkosiorek » Mar 14 2010 7:36am

funny enough there just happens to be an old thread called

"Using Reed Switches for E-Brakes" in the technical reference section.
http://www.endless-sphere.com/forums/vi ... 16&t=11760

explains why NO reed switches should be used. might have saved you a little experimentation. though it does concentrate mostly on mounting them to the levers themselves. your method is valid as well.

would you mind if i added your posts to the reference section?

rick
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rscamp   1 kW

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Re: Using Reed Switches to Disable the Controller on a Trike

Post by rscamp » Mar 14 2010 8:59am

rkosiorek wrote:funny enough there just happens to be an old thread called

"Using Reed Switches for E-Brakes" in the technical reference section.
http://www.endless-sphere.com/forums/vi ... 16&t=11760

explains why NO reed switches should be used. might have saved you a little experimentation. though it does concentrate mostly on mounting them to the levers themselves. your method is valid as well.

would you mind if i added your posts to the reference section?

rick
Not at all.

What does not finding that other thread say about my forum searching prowess? :?

The experimentation or "waste of time" :) wasn't with the electrics - that was straightforward. The trial and error was with mounting methods. After several false starts I eventually turned down a Mirrcycle mirror mount on a lathe so I could fit the expansion mechanism in the steering arm tube to solidly lock the switch support bracket in place. I also started with attaching the magnet directly to the lever arm but this could only be bonded in place since the steel in this part is extremely hard and it couldn't be drilled with standard tool steel bits. Attaching a separate arm made of thin aluminum was the answer - it made adjustments much easier.

Keeping the wiring off the steering arms of the trike was a major objective, hence the contraption on the brake arms.

The final complication was that the small magnet created a "dead spot" in the middle of the reed switch. In other words, it was hard to activate the switch with a small magnet at the centre. Just offsetting the magnet a few mm solved this problem.

For reference, I used the MEDER Electronic MD-6 series switch, DigiKey P/N 374-1065-ND and the small 1/4" dia. rare earth magnets and corresponding holders from Lee Valley Tools. For environmental protection, the contacts were covered with silicone RTV and then the whole assembly sprayed with silicone conformal coat.

Closing the contacts is all that is needed to activate the throttle cutoff, but that isn't enough for me.

Oh no, I have to make things more complicated. :roll:

So now I'm running 12V through these switches to activate a 2P2T relay. One pole closes contacts for the throttle cutoff and the other passes 12V for a brake light. The 12V comes from a DC-DC regulator. The idea is to power any other 12V accessories I may want to add, such as a headlight, tail light, turn signals, horn, or whatever. A cheapie horn and an LED brake/turn signal thingy have been ordered.

Yup. Soon I'll have the little electric car I always wanted as a child... :lol:
Last edited by rscamp on Mar 14 2010 12:25pm, edited 1 time in total.
Rob
Trice QNT with Astro 3215 8T & V4 Drive
Trice Q with Bafang BBS02 at 48V with "500W" limit
Astro 3210-12T + Neugart PLQE60 20:1 Chain-Puller Spring '17

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rscamp   1 kW

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Re: Using Reed Switches to Disable the Controller on a Trike

Post by rscamp » Mar 14 2010 9:04am

Is it...

Yes it is that easy to embed.

Next time...
Rob
Trice QNT with Astro 3215 8T & V4 Drive
Trice Q with Bafang BBS02 at 48V with "500W" limit
Astro 3210-12T + Neugart PLQE60 20:1 Chain-Puller Spring '17

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