Problems with magnetic reed switches (from Colkan Eagle thread)

dive2dive2000 · 6th April 2007, 01:41

Quote: (Originally Posted by Dave Sutton)

This is a part that I attempted to retrofit to my Mark-15 (cabled for me by a former employee/consultant/whatever for SM), and it was so unreliable that I binned it. It lives under my bench... would be a nice idea if it was reliable. I made a mechanical rotary switch at the end of a cable and potted it and it works a charm. Would be easier to do for Prism due to easier to source cables (or just cut off the switch and then wire to the old cable). I needed to cut off the SM one on a trip and ended up twisting the wire ends together to turn the rig on for two weeks.... *that* worked reliably!

Dave

Hi Dave,

Well glad to see you survived your test mission, welcome home. I was wondering if you could write a tear down article on the MK15.5 most other units have one posted on Rebreather World. I think the grand daddy of them all should have one too. I remember Kevins old web site you to have one, but cant seem to find the link.

Kevin if your surfing maybe you could re print your mk15.5 tear down

rdmmdr · 6th April 2007, 04:01

guys

reed switches work, they will not put up with 50 g shock loads from the ribbi flying over the wave crests. Nor were they designed to do so. by the way your back was not either. spinal fussion or reed switch replacment which one is cheaper. if you fly your car over a ditch and it dos'e not work do yo blame ford. if you beat the gear up and it fails it is not the gears fault it is the operator.

ps look at the transom, if you are breaking reed switches then you are breaking motors

rick m

**DeepBlueInnovation** · 6th April 2007, 04:12

Quote: (Originally Posted by rdmmdr)

guys

reed switches work, they will not put up with 50 g shock loads from the ribbi flying over the wave crests. Nor were they designed to do so. by the way your back was not either. spinal fussion or reed switch replacment which one is cheaper. if you fly your car over a ditch and it dos'e not work do yo blame ford. if you beat the gear up and it fails it is not the gears fault it is the operator.

ps look at the transom, if you are breaking reed switches then you are breaking motors

rick m

Rick,

I am not sure if the above is an attempt at humour, if so then some smiley faces would convey this a little better. If this was posted seriously then I suggest you read some of the above posts a little more closely - there is mention of rust and other factors that have caused problems with the switches - in some cases from the original manufacturer.

The assumption that we all dive from RIBs would also be incorrect speaking for myself that would seem like entirely too much hard work - I dive from large, comfortable boats with bunks, catered meals etc

Cheers,

Ben.

rdmmdr · 6th April 2007, 05:00

Ben
the issue of magnet corrosion, is different from the physical failure of the reed switches. most magnetic materials are highly corrosive in a water enviroment. what i was writing about was the reciver, the magnet is the sender. i have taken some extreame ribbi rides, alameda to the fairlones and back in 16 footers. i would not expect electronics to work afterwords. niether did my body for a few days.
rick m

**Dave Sutton** · 6th April 2007, 11:24

Quote: (Originally Posted by dive2dive2000)

the rotary design was not reliable and *I think* the o-ring would strip out after so many turns

And the new one is not reliable either....

My rotary has been working well for a while now, but the twisting the wires together *always* worked...

Dave

AD_ward9 · 6th April 2007, 13:21

Contacts look very simple, but need very extensive testing to approve for an application. I remember 20 years ago, tests on relays from over 80 different companies to drive an electric window openner. Only relays from 2 companies passed: most failed in 30 minutes. We designed in NEC relays, and the unit worked. No complaints in high volume.

Ensuring a relay contact does not shake open, or weld together, or self weld (e.g. gold on gold), is a lot of work. Reed relays are more fragile in this respect than other relays. Rather than try to solve this, given the low volumes needed for rebreathers, it is much better to eliminate the contact. Today, there is no excuse not to do so. Hall sensors are cheaper than reed switches and some are low enough power to act as a soft start switch for rebreather and PPO2 monitor applications.

On the magnet, to stop corrosion, ion implant them with carbon. Then they will never corrode, and the surface is diamond like.

Alex

wizbang · 7th April 2007, 13:08

Quote: (Originally Posted by rdmmdr)

Ben
the issue of magnet corrosion, is different from the physical failure of the reed switches. most magnetic materials are highly corrosive in a water enviroment. what i was writing about was the reciver, the magnet is the sender. i have taken some extreame ribbi rides, alameda to the fairlones and back in 16 footers. i would not expect electronics to work afterwords. niether did my body for a few days.
rick m

Rick, another read through might be in order. Underwaterbear was talking about rust that had formed on the legs of the reed switch inside his on/off switch housing.

Ben, dont you also have a reed switch, straight from the manufacturer that isn't quite right?

I am a fan of reed switches but like all things electrical, they don't seem to go well with divers in the marine environment.

If you are having no troubles with your reed switch/s, more power to you.
(did you like the pun

)

6th April 2007, 01:41	#21 (permalink)
dive2dive2000 PRISM DIVER & LUVIN IT! Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Feb 2005 Location: Long Island, NY Posts: 788	Re: Problems with magnetic reed switches (from Colkan Eagle thread) Quote: (Originally Posted by Dave Sutton) This is a part that I attempted to retrofit to my Mark-15 (cabled for me by a former employee/consultant/whatever for SM), and it was so unreliable that I binned it. It lives under my bench... would be a nice idea if it was reliable. I made a mechanical rotary switch at the end of a cable and potted it and it works a charm. Would be easier to do for Prism due to easier to source cables (or just cut off the switch and then wire to the old cable). I needed to cut off the SM one on a trip and ended up twisting the wire ends together to turn the rig on for two weeks.... that worked reliably! Dave Hi Dave, Well glad to see you survived your test mission, welcome home. I was wondering if you could write a tear down article on the MK15.5 most other units have one posted on Rebreather World. I think the grand daddy of them all should have one too. I remember Kevins old web site you to have one, but cant seem to find the link. Kevin if your surfing maybe you could re print your mk15.5 tear down __________________ Safe Diving, Martin
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6th April 2007, 04:01	#22 (permalink)
rdmmdr designer of death Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2006 Location: kerman,california Posts: 372	Re: Problems with magnetic reed switches (from Colkan Eagle thread) guys reed switches work, they will not put up with 50 g shock loads from the ribbi flying over the wave crests. Nor were they designed to do so. by the way your back was not either. spinal fussion or reed switch replacment which one is cheaper. if you fly your car over a ditch and it dos'e not work do yo blame ford. if you beat the gear up and it fails it is not the gears fault it is the operator. ps look at the transom, if you are breaking reed switches then you are breaking motors rick m
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6th April 2007, 04:12	#23 (permalink)
DeepBlueInnovation Learning to Kiss Current Rebreather/s: Not Bought Yet Other Rebreather/s: Prism Topaz Not Bought Yet Join Date: Sep 2005 Location: Perth, Western Australia Posts: 358	Re: Problems with magnetic reed switches (from Colkan Eagle thread) Quote: (Originally Posted by rdmmdr) guys reed switches work, they will not put up with 50 g shock loads from the ribbi flying over the wave crests. Nor were they designed to do so. by the way your back was not either. spinal fussion or reed switch replacment which one is cheaper. if you fly your car over a ditch and it dos'e not work do yo blame ford. if you beat the gear up and it fails it is not the gears fault it is the operator. ps look at the transom, if you are breaking reed switches then you are breaking motors rick m Rick, I am not sure if the above is an attempt at humour, if so then some smiley faces would convey this a little better. If this was posted seriously then I suggest you read some of the above posts a little more closely - there is mention of rust and other factors that have caused problems with the switches - in some cases from the original manufacturer. The assumption that we all dive from RIBs would also be incorrect speaking for myself that would seem like entirely too much hard work - I dive from large, comfortable boats with bunks, catered meals etc Cheers, Ben.
(Online)

6th April 2007, 05:00	#24 (permalink)
rdmmdr designer of death Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2006 Location: kerman,california Posts: 372	Re: Problems with magnetic reed switches (from Colkan Eagle thread) Ben the issue of magnet corrosion, is different from the physical failure of the reed switches. most magnetic materials are highly corrosive in a water enviroment. what i was writing about was the reciver, the magnet is the sender. i have taken some extreame ribbi rides, alameda to the fairlones and back in 16 footers. i would not expect electronics to work afterwords. niether did my body for a few days. rick m
(Offline)

6th April 2007, 11:24	#25 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,674	Re: Problems with magnetic reed switches (from Colkan Eagle thread) Quote: (Originally Posted by dive2dive2000) the rotary design was not reliable and I think the o-ring would strip out after so many turns And the new one is not reliable either.... My rotary has been working well for a while now, but the twisting the wires together always worked... Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
(Offline)

6th April 2007, 13:21	#26 (permalink)
AD_ward9 So much more to learn Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jun 2005 Location: Scotland Posts: 1,868	Re: Problems with magnetic reed switches (from Colkan Eagle thread) Contacts look very simple, but need very extensive testing to approve for an application. I remember 20 years ago, tests on relays from over 80 different companies to drive an electric window openner. Only relays from 2 companies passed: most failed in 30 minutes. We designed in NEC relays, and the unit worked. No complaints in high volume. Ensuring a relay contact does not shake open, or weld together, or self weld (e.g. gold on gold), is a lot of work. Reed relays are more fragile in this respect than other relays. Rather than try to solve this, given the low volumes needed for rebreathers, it is much better to eliminate the contact. Today, there is no excuse not to do so. Hall sensors are cheaper than reed switches and some are low enough power to act as a soft start switch for rebreather and PPO2 monitor applications. On the magnet, to stop corrosion, ion implant them with carbon. Then they will never corrode, and the surface is diamond like. Alex
(Offline)

7th April 2007, 13:08	#27 (permalink)
wizbang WEB MERMEN Current Rebreather/s: Inspiration Classic Dolphin Home Build Other Rebreather/s: Not Bought Yet Inspiration Vision Evolution Prism Topaz Sport Kiss Classic Kiss Dolphin Home Build Join Date: Feb 2005 Location: Perth Australia Posts: 386	Re: Problems with magnetic reed switches (from Colkan Eagle thread) Quote: (Originally Posted by rdmmdr) Ben the issue of magnet corrosion, is different from the physical failure of the reed switches. most magnetic materials are highly corrosive in a water enviroment. what i was writing about was the reciver, the magnet is the sender. i have taken some extreame ribbi rides, alameda to the fairlones and back in 16 footers. i would not expect electronics to work afterwords. niether did my body for a few days. rick m Rick, another read through might be in order. Underwaterbear was talking about rust that had formed on the legs of the reed switch inside his on/off switch housing. Ben, dont you also have a reed switch, straight from the manufacturer that isn't quite right? I am a fan of reed switches but like all things electrical, they don't seem to go well with divers in the marine environment. If you are having no troubles with your reed switch/s, more power to you. (did you like the pun )
(Offline)

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