Floating battery between springs.. whodoneit?

I remember reading a thread 'way back when' that somebody had a picture of a neat concept of a battery suspended between two springs.. a button at the back of the light... in any event I think it was having to do with a POP controller and a button on the front side of the battery.

I'm trying to find out who was the poster of that concept.. floating battery between two springs.. anybody that can point me in the right direction? Not having any luck with searches.

-awr

andrewwynn said:

I remember reading a thread 'way back when' that somebody had a picture of a neat concept of a battery suspended between two springs.. a button at the back of the light... in any event I think it was having to do with a POP controller and a button on the front side of the battery.

I'm trying to find out who was the poster of that concept.. floating battery between two springs.. anybody that can point me in the right direction? Not having any luck with searches.

-awr

Click to expand...

That was the arc 4 light.

It had some serious problems with variations in battery length and switch activation.

Hi Andrew - If you mean the concept of having the battery permanently under load between two springs, that concept was used a long time ago in flashlights, and IMHO, is still a great way to go. I use it in my CR2 side x side, but certainly did not invent it. The reasons are simple - It makes up for variation in battery length, and it reduces the shock that the cells see when dropped.

The only negative, is that people are used to the "keying" concept of the spring being the (-) end of the cell.

If you mean to use them in a light which comes on by "twisting the cell space shorter", might not work so well.

i've not seen the arc 4 how it does it.. i'm talking about somebody posted to CPF a sketch he made of a light with the battery held between two springs... I believe there was a solid rod up through the 'neg' spring and went to the back of the light pushbutton... to push just the battery forward compressing the 'pos' spring.. there was a tiny switch inside the pos spring that was pressed to control μC. Maybe that is also how the arc4 works but i got the impression this was a completely different design, maybe somebody was just drawing how the arc4 works.

In general i can't stand designs that have inconsistancies in how they neg. is spring'd or not.. i had a GPS that SOME of the pos. terminals were springs and SOME of the neg. terminals were springs... extremely irritating.. batteries are supposed to be instinctive to put in.

-awr

I think I posted a sketch here a few years back with a tail switch having a rod that pushed the battery towards a force sensor which was located underneath the positive contact. There was a way to tilt the switch in order to lock it at the desired light intensity. But I don't think there was a negative contact spring. Makes more sense to put a spring in the front I think, since inertia then won't affect the output until it overcomes the spring preload and disengages the rear contact.

the sketch i'm talking about had just a microswitch.. and a spring on both sides of the battery. pushing the button on the tailcap moves the battery forward and presses the button through the front spring.

I would love to see the sketch you are talking about though.

-awr

HDS designed Arc4, which was one of the most sensitive to battery length light I'm aware of. .040in one way or another was enough to make light not function properly.

pressing rear button engages 123, which then pressed a micro-switch in head assembly. Arc4 used gold contacts to carry the up to 1.5amps necessary to drive light.

Early Arc4's were surprisingly reliable, but all were prone to switch failure if dropped directly on tailswitch. flat tailcap mod takes away drop danger making early Arc4's very reliable with smaller footprint than current HDS lights.