Dive switches

[clint357]

I just made my first dive light using a single P7 and external battery pack....blah,blah,blah, I'll post pics later. I used a toggle switch with a waterproof boot but it just doesn't seem reliable for some reason. What are the best switches to use on dive lights. The smaller, the better for my application.

[Packhorse]

Reed switches are my preference.

[clint357]

Reed switches are my preference.

What type of setup do you prefer, or in what manner do you move the magnet over the switch?

[steve6690]

If you're set on a toggle switch, I use Salvo switches & boots and they are quite robust. If you can use a reed switch though, the benefits are obvious. I'd use a reed switch wherever I could.

[wes_wall]

Reed switch with a solid state relay is the way to go.

What do you call people who use prop@#@!$%^ for birth control?

Parents

Think about your little rubber doohickey on the toggle switch. It is not a question of 'if' but when it will fail. I know, they say "you should replace them on a regular basis." Define "regular." There is too much at risk to to play around with it. Moreover, I am an electrical buffoon. If I can make the reed switch work, you can too.

I think the trick is making the trigger (the outside part) lock in the proper position, and not flop around. I use a stainless ball and detent plunger arrangement with the detent in the canister lid. This requires no penetration of the canister, and no possibility of a leak.

[DM51]

There have been one or two threads mentioning Hall Effect switches.

Here also is a wikipedia entry.

[jtivat]

Reed switch with a solid state relay is the way to go.

What do you call people who use prop@#@!$%^ for birth control?

Parents

Think about your little rubber doohickey on the toggle switch. It is not a question of 'if' but when it will fail. I know, they say "you should replace them on a regular basis." Define "regular." There is too much at risk to to play around with it. Moreover, I am an electrical buffoon. If I can make the reed switch work, you can too.

I think the trick is making the trigger (the outside part) lock in the proper position, and not flop around. I use a stainless ball and detent plunger arrangement with the detent in the canister lid. This requires no penetration of the canister, and no possibility of a leak.

None of the large can light makers are using them there must be a reason??

[wes_wall]

There is s very good reason the dive light manufacturers don't use reed switches: money.

These things are expensive, and for the most part were cobbled together by folks like us who want something now. A reed switch requires real technology which takes time. Anyway, when the light floods, who would a 'normal person' (folks who are not like the members of CPF) send it to for rebuilding? Do you think they rebuild it for free? I certainly wouldn't.

Look at the European manufacturers: Harteberger for example, what type of switch do they use? What about OxyCheq? (even though they are an American company their Dive lights are imported from (i think) Czheckoslovakia.

How about Greenforce? IMHO GF has the best solution: eliminate the switch altogether.

On top of all these good reasons, after the battery gives up, most divers are already looking for the next great thing.

So, yes they do have a reason, several in fact.

[jtivat]

There is s very good reason the dive light manufacturers don't use reed switches: money.

These things are expensive, and for the most part were cobbled together by folks like us who want something now. A reed switch requires real technology which takes time. Anyway, when the light floods, who would a 'normal person' (folks who are not like the members of CPF) send it to for rebuilding? Do you think they rebuild it for free? I certainly wouldn't.

Look at the European manufacturers: Harteberger for example, what type of switch do they use? What about OxyCheq? (even though they are an American company their Dive lights are imported from (i think) Czheckoslovakia.

How about Greenforce? IMHO GF has the best solution: eliminate the switch altogether.

On top of all these good reasons, after the battery gives up, most divers are already looking for the next great thing.

So, yes they do have a reason, several in fact.

Ok we are talking lights that cost between $500 and $2000 dollars. How much are reed switches?

This is a quote from Carl the owner of Sartek.
"Hi,
Reed switches have a tendency to become magnetized and will stick after time. The current required by an HID would cause you to use a fairly large reed switch, unless you are using a relay...which complicates matters. Larger reed switches need more magnetic field to actuate, so a larger magnet or thinner wall. Our rotary switches are double "O" ring sealed and have not had a seal leak for all the years we have been making them. Our switches are rated for over 1 million cycles and for 5 to 10 amps depending on the model.
Regards, Carl "

[jtivat]

Also both Sartek and Salvo stand behind there products and I have seen both repair lights for free when it was clearly diver error tat caused the problem. I have heard the same about Halcyon

[wes_wall]

BTW: I am loving this debate! IT is exhillarating.

I believe the point is for the light NOT to fail, not service after the failure. Although it is great to hear that those two provide excellent customer service. I actually thought good customer service was dead; apparently not true at Halcyon and Salvo.

However from a strict engineering standpoint, if it can happen it will. If there is no penetration in the head or housing it will not leak. If there is an opening with 12 o-rings there is still a possibility that it will leak eventually. ( I know I am getting ridiculous, but I am pretty stubborn about making a point....ok just stubborn in general.)

Anyway the best solution IMHO is no switch at all.

In industry reed switches -with a solid state relay- and/or Hall effect sensors are used extensively in highly un-defeat-able safety interlocks where if someone opens this door you will be injured, and maybe killed.

The reed switch itself cannot take the kind of currents we use today. The old Darrell-Allen (big yellow clunker) used a large one. I have a vintage Darrell-Allen light, just for a museum piece, and have never used it as it would take some work to get it going, but it is cool looking. Mine is neatly beaten up, but in very good condition for a 30+ year old thing that is well used.

Anyway, I really enjoy this debate. I think the bottom line is:
listen to everybody's opinion then do what ever you want. I think if I were building another one for me, I would go ahead with the reed with solid state relay, but if I were building one for you I would ask what you want.

I'd say go for it, carry a back up, no matter what switch you choose. The fun for me is trying different things. If you made it once, you can make it again. If it was ever made, it can be improved upon until it is perfect.

Please post pictures when you get something done.
Here are pictures of mine.
http://picasaweb.google.com/wes.newp...LEDDivelights#

[Packhorse]

The parts I use in my reed/mostfet switches cost me less than a waterproof toggle switch.
They do require a lot more work to implement mind you.

[gav6280]

The parts I use in my reed/mostfet switches cost me less than a waterproof toggle switch.
They do require a lot more work to implement mind you.

What's actually involved?

[Phaethon]

Any online links to dive switch suppliers???
Thanks!

[jspeybro]

did you have any particular switch in mind?

I think most of the options are just standard electronic components that can be ordered in about any electronics shop or online website like Farnell. In case of a toggle switch you'll need the rubber booth but they usually have these too.

so far I've seen mostly toggle switches, reed switches and twist-to-make-contact systems.

Johan

[Phaethon]

I was thinking about magnetic switches or sealed roatary switches with o-rings.... I can only find ip68 ones , not diving specific. Any links?

[H20doctor]

Ive used Glass Reed switches all the time.... simple and cheap... from 2.00 to 6.00 american ... just put a rare earth magnet in your dry glove and hold youre light and it comes on... or put it into a goodman handle..
http://www.73.com/a/0612.shtml
Nothing wrong with a Rubber boot either ... still works great

[Katolix]

I was thinking about magnetic switches or sealed roatary switches with o-rings....

This is something I was thinking about. A roatary switch with o-ring could use either magnet with reed switch or knob switch inside. No out-of-box solutions found so far. Trying to design it from scratch.

[Umibuta]

I am wondering why there is no mention of piezo switches? I am new to DIY by the way. Is it difficult to implement or is it the cost that the drawback?

[Packhorse]

I have never used Piezos before.
They do cost more and there is more to the circuit when using them.
Also when using multi mode drivers the piezos may not be able to select the various modes.

[lucca brassi]

May I ask you what is yours opinion about HALL switch ( not sensor ! )
To be concrete ;something like that :
http://www.melexis.com/Assets/US5881...heet_4824.aspx
(similar switches can be found in computer fans - they count RPMs)

- you have to be careful there are two types of hall switches :
- UNIPOLAR ( that we use - switches normally only on J-south pole )
- BIPOLAR ( they switches when switch go through change of magnetic field J-S (hysteresis ) and they are normaly used in computer fan brushless motors)

I have for myself a little separated feeling about that topic. so I wrote PROs and CONs

POSITIVE
-it is smaller then REED
-it is cheap
-it is much more simple to orientate in correct position (only one)
-simple to build in
-switches only on SOUTH pole magnet
-senses weak magnet field ( thick walls of enclosure- have choice between low /medium/high sensitivity version of switch-look datasheet)
-no sticking sticking of contact foils in REED capsule
-can be almost directly exchange REED in combination with few components (reed , resistor ,n-MOSFET)
-clean switching hysteresis (pulse)- built in schmidt trigger ( in case of half magnetised contact leafs in reed capsule)


NEGATIVE
- takes little current (2,5mA- in operation time , between traveling it is normal to disconect battery)
- needs another POWER component to switch power current (also REED need relay or FET too)

So what is yours opinion .

---------------------------------------------------------------------
About PIEZO :

I have see several lamps built with piezo most from :
http://www.pcmus.com/Dive-Photos/Mag...Dive-Light.htm
and some on MS MULTIPLY but....
- in fact this is keyswitch (not normal switch(( push and hold) even they exsist that too))
- to big switch
- to expensive
- not right environment for that kind sensor (it is IP67-68 but because of technology of sealing-encapulating -it is mean for harsh environment )
- need aditional switching circuit ( it is not problem but... (debouncing))
- it is too sensitive (detects quick pressure difference - in water it is pressure all the time but it is constant)

..... dont like it at all!

[Packhorse]

I cant comment on hall effect sensors or switches as I have not used them.

But I can say the only problem I have had with reed switches is breaking them during installation.

I have never had them stick.
I have only ever used 3 components. Mosfet, reed & resistor.
Cost is $2nz or less. Its not an issue.

hall effect sensors/ switches may be better. I just have not tried them

[SUBjohan]

May I ask you what is yours opinion

I have never used them but I think I am going to use them in my new project, it looks like a nice upgrade above a reed switch.

Thanx for the heads up

Greetz Johan

[gt40]

I found this link which explains usage of hall effect switch in non ee terms. They are using it to build a motor but the principle would work the same if you used it as a trigger switch with a fet.

http://www.simplemotor.com/hallswitch.htm

[DIWdiver]

In case that link didn't explain it well enough, a Hall Effect Switch is an integrated circuit that has three pins - power, ground, and output. The output changes in the presence of a magnet.

I love hall switches (used 3 in my light), but they are definitely not suitable for all applications. I think the primary benefit in dive lights is that they can be very small, like 0.1 - 0.2 inches square. The primary drawback is that they draw power all the time. Most are in the 5-20 mA range. There are some much lower than that, but they have very limited voltage range, making them more difficult to use.

With small neodymium magnets, many hall switches will operate at distances of 0.25" or more, which I think is comparable to typical low-current reed switches (someone please correct me if I'm wrong).

Another problem with hall switches is that there are many to choose from, and they have VERY different behaviors and specifications. Unless you can read and understand the data sheets, you should probably depend on someone else to suggest an appropriate part for your application. If anyone is really itching to try them out and needs assistance, PM me and I'll see if I can help.

D

[DIWdiver]

There is a large manufacturer that used reed switches for many years - Princeton Tec. The TEC-400 that I have used for years uses a reed switch. It's simple and cheap. When the reed switch on mine broke, I was able to replace it.

The main drawback of magnetic switches that I have seen is the magnet.

I dive wrecks mostly, and the magnet is always picking up fine iron particles. They get in the sliding mechanism, making it hard to operate. They also can extend the magnetic field of the magnet, making it hard to turn off the light. You can clean it with the spray nozzle on a hose, but you can't do that during a dive!

[350xfire]

By far the easiest is to use the toggle with boot. Now, the problem lies in which boot you use. Most of us DIYers frequent Ebay for parts. We search toggle boot and are lured in by the $2.25 free shipping toggle boot. Believe me I fell for that one. Then I went to a surplus store and found some for about $1.25. They both sucked. They are pretty thin and flimsy. What happens is that, when pressurized, to lets say 260', the air in the boot is pressurized and the boot collapses around the toggle switch's shaft causing a tear at the bottom. I had about 2-3 failures like that.

I finally found a company APM Hexseal that has by far the best boots out there. So I ordered up some. Much thicker and better. If anyone wants any of these, let me know because I ordered plenty to take advantage of wholesale pricing.

[DIWdiver]

I wouldn't question that the toggle switch is by far the easiest to understand and implement. However it is also, IMHO, the most likely to fail.

[Z-Max]

The reed switch itself cannot take the kind of currents we use today.

This problem has the simple decision:

[kl3vr]

Excellent thread!
Thx for introducing me to Hall switches and the mosfet diagram!
Can the hall be used as a potentiometer of sorts, to control the brightness? I think it'd be such a quality feeling to gracefully ramp up the lumens instead of in modes. Plus it'd be the simplest UI. A diagram would be awesome.

*** What about a reed controlled hall switch! The reed is there only to turn on the hall switch when its needed. One magnet would turn on the reed, supplying power to the Hall, which would then tell the driver board how much to feed the lamp. Sounds like *fun* to assemble but I did say quality....