Normally Closed reed switched

[KirstinS]

Anyone have any idea where I can get a plastic encased one of these ?

I find plenty of normally open reed switches but normally closed seem to be very hard to source indeed

I want a circuit to be On when a magnet is present but Off when it is removed

The only ones I found on ebay turned out to actually be normally open type on arrival today

Many thanks

 

[Alan Quay]

You can use another magnet to make 'em N.C.

http://m.instructables.com/id/Make-a-Magnetic-Reed-Switch-Work-Backwards-sort-o/

 

[KirstinS]

You can use another magnet to make 'em N.C.

http://m.instructables.com/id/Make-a-Magnetic-Reed-Switch-Work-Backwards-sort-o/

I did see that thanks

But I'm not convinced its robust enough for ebike use. All the bouncing around seems likely to shift the delicate balance

 

[Alan Quay]

I admit that I've never used this in the real world, on a bike. I prefer a hidden wire brake sensor as I don't have hydraulic brakes.

I've tested it on the bench though. It seemed fairly stable and repeatable.

At the end of the day magnetic properties are fairly constant.

 

[KirstinS]

This is for another use

I think you need normally open for av brake mod. Never done one mind

The search continues!

 

[Geebee]

I dont know whether Jaycar ship internationally but http://www.jaycar.com.au/productView.asp?ID=LA5070&w=reed+switch&form=KEYWORD

Or Ebay (have to make your own housing) and guaranteed to have the right operation as this and the Jacar one are double throw
http://www.ebay.com.au/itm/10-Reed-Glass-Magnetic-Switches-N-O-N-C-SPDT-2-5X14MM-15VDC-30VDC-/261473468776?pt=AU_B_I_Electrical_Test_Equipment&hash=item3ce1088168

 

[MikeRo]

Anyone have any idea where I can get a plastic encased one of these ?

I find plenty of normally open reed switches but normally closed seem to be very hard to source indeed

I want a circuit to be On when a magnet is present but Off when it is removed

The only ones I found on ebay turned out to actually be normally open type on arrival today

Many thanks

Huh? You need normally open then. The switch closes when a magnetic field is present, otherwise its open...

 

[MikeRo]

Or use a 3114 hall sensor?

 

[pdarnett]

Just bought some of these from Banggood, they're for Arduino but I'm using them on the bike, they put out 5v when a magnet is near (or drop to 0v if you want it that way).

 

[pdarnett]

Just thinking I may have some reeds for a brake mod all sealed up with mounting holes. Give me five minutes and I'll look in the garage.

 

[pdarnett]

Yep these are the ones, one hole for mounting to the lever body with a locating dot to fit into another small hole. need a magnet on the lever arm to close the circuit.

 

[KirstinS]

Huh? You need normally open then. The switch closes when a magnetic field is present, otherwise its open...

Sorry ! I managed to confuse myself clearly

Let me try again

I am after a reed switchb that is open when the magnet is present

When the magnet is taken away the reed costs and completed the circuit

I think this is called normally closed

Sorry for ( my) confusion !

 

[KirstinS]

View attachment 10117
Just bought some of these from Banggood, they're for Arduino but I'm using them on the bike, they put out 5v when a magnet is near (or drop to 0v if you want it that way).

I wish I understood this !

 

[KirstinS]

Yep these are the ones, one hole for mounting to the lever body with a locating dot to fit into another small hole. need a magnet on the lever arm to close the circuit.

View attachment 10124

Thanks very much

Ideal if I hasn't got my wires crossed !

As above I need an open circuit when magnet is present

 

[KirstinS]

Although if you you were offering one for sale I'd be keen, I've been without brake cutouts for a couple weeks ( bike rejig)

Cheers

 

[pdarnett]

Which controller have you got?

 

[KirstinS]

A ku65 (36v ) overvokted to 48

 

[pdarnett]

Ok now I get it, the KU65 needs to see 5V when the brakes are applied so the two wires to the lever are 5v and controller brake input. When switch is closed brakes are being applied. Does that sound right?

 

[trex]

you are nearly always better off with a Hall sensor. Small, sensitive, no bounce, easy to pot and glue even inside the brake body and you simply need to flip the magnet to change the polarity of the signal.

 

[pdarnett]

I've an idea, mount the reed switch like in this video and it'll only close the circuit when the brake is being pulled.

PM me if you want a pair of those reeds and I'll stick a couple in the mail.