Mag C switch and multi mode driver

PaulH · Mar 12, 2009

With a fair amount of help from Stefan, I now have a 2C LiIon MC-E 2S2P mag. Its works brilliantly except for the switch. Either I have put it back together badly, or it just doesn't work well with a multimode drive. When I turn the light on - sometimes is stays at the selected mode, other times it jumps a mode, and other times it jumps two modes.

Its as if the switch itself conects the circuit, then disconnects, then connects again on each click, before staying in the on position.

Has anyone come across this before. Is there a quick fix? All I can think to do is to change modes by losening the tail cap slightly and then quickly tightening it.

Many thanks,

Paul

tx101 · Mar 12, 2009

What kind of multi mode driver are you using ???

Are you using a D2Flex ?

If you are then the switch needs to be modded to a momentary action

Give me a minute and I will try to find the tutorial

EDIT .... found it ... tutorial by Wquiles

https://www.candlepowerforums.com/threads/189336

PaulH · Mar 12, 2009

Its one of KD's multimode AMC7135 drivers, made into a sandwich with some addtional 3 x 7135 driver boards.

Thanks.

nailbender · Mar 12, 2009

That switch does not need to be momentary with that driver. I hate to say it but if your switch turns it on and off everytime then there is a good chance it is the driver with the switcher on it. If the switch turns it on and off every time then the switch is good.

You only used one board that had levels on it right Paul.

Dave

StefanFS · Mar 12, 2009

There's no easy solution for this. Mag C switches sometimes exhibit that behaviour. I think I warned you that this might happen. The only solution is to rewire it to a one level light. Desolder the microcontroller chip on the MM-driver and use it with your existing 2S2P AMC7135 sandwich. Or you could use a simple AMC7135 1400 mA one level driver to get 700 mA to each die with your setup. (Overdriving with a 5 x AMC7135 sandwich will be brighter).

The driver used here is the 2S2P version as described here:
https://www.candlepowerforums.com/threads/212835

/Stefan

darkzero · Mar 12, 2009

I agree with StefanFS. I've never had this happen to myself since I choose never to build a multimode with C switch because of this behaviour. This behaviour is one of things I hate about the C switch but I deal with it because I prefer the C size of the D.

Only time I do multimode with Cs is when using George's (TaskLED) drivers which requires the switch to modded into momentary.

StefanFS · Mar 12, 2009

Paul,

That post above wasn't as clear as it should have been. You also need to preserve the positive in path to the VDD pin on the AMC7135 chips when you remove the microcontroller.
That means a simple solder and copper wire bridge as shown in the pic. I also removed the diode and the capacitor for the microcontroller memory. You can keep the diode and remove the brown capaicitor marked C1 as it's useless without the microcontroller. The black DIODE marked D1 protects against reverse voltage but will skim a tenth of a volt or so from voltage in. Keep it or lose it...

nailbender · Mar 12, 2009

I have even had a couple of D2flex on a c switch act funny Will, removed them could find nothing wrong rewired them to the D2flex and they work fine. (for now)

On the other I guess I had better knock on wood I have two C mags with MC-E in them and KD MC-E 3 level switches that work flawlessly but they only need the switch hooked to positive and negative no momentary.

Dave

Sorry Stefan I did not read close enough to see you were working with paul, I thought maybe the sandwich was made from multi level boards and they were butting heads on the switcher ics.

Mr_Light · Mar 12, 2009

I have encountered this behaviour with every C Mag switch I have come across. I just had to swap in a single mode driver for a multimode a couple of weeks ago when I forgot about this difference.

Greg G · Mar 12, 2009

Paul, I had this problem on a 2 C P7 build that has a Shark Buck w/Remora for 3 levels. I would cycle to the mode I wanted with the momentary function of the switch, but when I pushed the switch all the way in to lock the mode in it would lose contact momentarily and then switch to the next mode.

After some use it quit, but I took the switch apart anyway to see what might be doing it. It appears to me that the circular contact is bouncing off the stationary contacts when locking it in. Possibly be a stronger spring would prevent that. Something you can try anyway.

PaulH · Mar 12, 2009

Thank you all for your replies. A number of things to try there.

Stefan... I remember you did warn me!!!

I have another mag c body that I was going to use for a single mode P7, so I might try to see if that switch does the same.

Thanks everyone!

DonShock · Mar 13, 2009

What's causing the "multiple clicks" is the self cleaning feature of the MagC switch. Every time you click the switch, it rotates a part of the switch so that the electrical contact isn't made in the same spot every time. But this can lead to breaking contact for a split second as it rotates. Normally this isn't noticed, but it can trigger the electronics in a multi-mode driver. I built a light a few years ago that experienced this problem.

Fortunately, I came up with a solution. It defeats the self cleaning feature but dramatically improves the operation. There is a small white plastic part in the center of the switch that has ribs on it that fit into slots in the large metal contact. You can see them in this exploded diagram photo:

The trick is to keep the normal switch operation, but prevent the metal contact from rotating. The first modification I tried stopped the rotation but also prevented the normal operation. Here's a closeup of the modification I finally came up with. The upper section has the ribs removed so it can no longer turn the metal contact, but the bottom is intact which is needed for normal operation.

Techjunkie · Mar 13, 2009

DonShock said:
What's causing the "multiple clicks" is the self cleaning feature of the MagC switch. Every time you click the switch, it rotates a part of the switch so that the electrical contact isn't made in the same spot every time. But this can lead to breaking contact for a split second as it rotates. Normally this isn't noticed, but it can trigger the electronics in a multi-mode driver. I built a light a few years ago that experienced this problem.

Fortunately, I came up with a solution. It defeats the self cleaning feature but dramatically improves the operation. There is a small white plastic part in the center of the switch that has ribs on it that fit into slots in the large metal contact. You can see them in this exploded diagram photo:

The trick is to keep the normal switch operation, but prevent the metal contact from rotating. The first modification I tried stopped the rotation but also prevented the normal operation. Here's a closeup of the modification I finally came up with. The upper section has the ribs removed so it can no longer turn the metal contact, but the bottom is intact which is needed for normal operation.

Don,

That is an awesome, elegant solution to the contact bounce problem. I'm not big on modes in Mags, but I'm keeping this one for future reference in case that changes. Thanks!

download · Mar 13, 2009

I got this problem from FluPIC with C switch for long time ago.
Luckily, latest 7135x8 solve this problem, it will not jump the mode anymore.
It is working wonderfully now.

Greg G · Mar 13, 2009

Thanks Don. Putting that in my memory bank.

Icarus · Oct 13, 2009

DonShock said:
What's causing the "multiple clicks" is the self cleaning feature of the MagC switch. Every time you click the switch, it rotates a part of the switch so that the electrical contact isn't made in the same spot every time. But this can lead to breaking contact for a split second as it rotates. Normally this isn't noticed, but it can trigger the electronics in a multi-mode driver. I built a light a few years ago that experienced this problem.

Fortunately, I came up with a solution. It defeats the self cleaning feature but dramatically improves the operation. There is a small white plastic part in the center of the switch that has ribs on it that fit into slots in the large metal contact. You can see them in this exploded diagram photo:

The trick is to keep the normal switch operation, but prevent the metal contact from rotating. The first modification I tried stopped the rotation but also prevented the normal operation. Here's a closeup of the modification I finally came up with. The upper section has the ribs removed so it can no longer turn the metal contact, but the bottom is intact which is needed for normal operation.

:goodjob: Thanks for posting!

kosPap · Mar 13, 2010

DonShock said:
Fortunately, I came up with a solution. It defeats the self cleaning feature but dramatically improves the operation. There is a small white plastic part in the center of the switch that has ribs on it that fit into slots in the large metal contact. You can see them in this exploded diagram photo:

http://img250.imageshack.us/my.php?image=explodedmagcswitchqk1.jpg
The trick is to keep the normal switch operation, but prevent the metal contact from rotating. The first modification I tried stopped the rotation but also prevented the normal operation. Here's a closeup of the modification I finally came up with. The upper section has the ribs removed so it can no longer turn the metal contact, but the bottom is intact which is needed for normal operation.

first of all let me express my thanks for this "lifesaving" mod....

the I would ike a little help on my implementation of it....

I did it, checked function, but the moment I placed the switch module in the barrel and tighened the allen screw I lost all function..it simply got stuck...

I tried several times and I always loose some whenever i insert the allen. The best I could get is:
-removal of the silver gasket
-semi-tighten the module
-the switch woks but it has to be pressed down further tyo click-off

Anyone has an idea what is going on?

DonShock · Mar 13, 2010

I am guessing here, but you might want to check / modify your cutouts. When I did this, I found the modified part would hang up on the metal contact if the edges of the cutout weren't sloped like in the photo. The idea is to keep the ends of the ribs intact so it still engages the clicky part of the switch normally. But you need to have the cutout be smooth enough that it doesn't hang up on the metal ring as it rotates.

Aircraft800 · Mar 13, 2010

I also suffered from "Switch Bounce" in my "C" mags, but another member here way back said to stretch the spring circled to about 1 + 1/2 it's length. Don't over do it, you can't squish it back

. The key is, stretch a little, give it a try and repeat till you succeed.

I have successfully done this many times, and no jumping modes now.

Photo borrowed from DonShock

kosPap · Mar 13, 2010

DonShock said:
I am guessing here, but you might want to check / modify your cutouts. When I did this, I found the modified part would hang up on the metal contact if the edges of the cutout weren't sloped like in the photo. The idea is to keep the ends of the ribs intact so it still engages the clicky part of the switch normally. But you need to have the cutout be smooth enough that it doesn't hang up on the metal ring as it rotates.

indeed I have taken good care of it...chamfered the edges too etc....

aircraft800 thanks for the tip....I will try it NEXt time....

tnx, kostas

Mag C switch and multi mode driver

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