Why wireless machine for Sabre needed to wear conductive t-shirt?

[Wanda]

Do any one can tell me, why wireless machine for sabre needs conductive T-shirt?

How do it function wear under the normal Metal Vest?

???

[esskreemr]

The wireless system requires your body to be part of the circuit (in simple terms). This conductive material lined t-shirt is how the system makes contact with the body. One note, if you deside to buy this system, it will only work on sabre and you better get several t-shirts because the system malfunctions when the t-shirt becomes wet. At world cups they have to change shirts after every round of DEs.

http://www.fechtsport-langenkamp.de/...arget=d97.html

[Wanda]

It doesn't explain, how do it function?

[Craig]

Originally Posted by Wanda

Do any one can tell me, why wireless machine for sabre needs conductive T-shirt?

How do it function wear under the normal Metal Vest?

???

StM is the manufacturer - go to www.stm-fencing.com to see what information they have.

Moving this to Armory...

Craig

[esskreemr]

Originally Posted by Wanda

It doesn't explain, how do it function?

Wanda, these changes are to make fencing more television friendly. The scoring circuit in sabre was too simple and problems are easily fixed by swapping out the body cord. The new wireless design will introduce a layer of complexity that will result in bout delays as equipment continuously malfunctions. This will become increasingly apparent as the equipment ages and the fencers through the course of the bout start to perspire. This is to make sabre fencing more conducive to television broadcast by offering more chances for longer breaks in the action. The longer breaks mean longer commercials.

[KD5MDK]

To be fair, listen to the sound of the reel cord hitting the floor (for concrete, wood or metal surfaces), and you'll see why it would be very difficult to broadcast them as is. I don't know how the current foil and epee video teams handle the noise spikes, but it must be tricky.

[babinet]

You made my day!

How it works? Well, I tried to find out in the last couple of month - without real success. While searching the answer i found this forum - without the answer but interesting other threads.

Here my first post with a few of my thoughts about the wireless system:

The system works without RF transmissions (except for the side lamps).
You can't close an electric circut with only one wire (or sabre).

Maybe they apply a HF-Voltage between the T-Shirt and the lame. When the sabre touches the lame, it works like an antenna and detects the HF-Voltage.

Anyone how knows more details?

[Wanda]

Originally Posted by babinet

You made my day!

How it works? Well, I tried to find out in the last couple of month - without real success. While searching the answer i found this forum - without the answer but interesting other threads.

Here my first post with a few of my thoughts about the wireless system:

The system works without RF transmissions (except for the side lamps).
You can't close an electric circut with only one wire (or sabre).

Maybe they apply a HF-Voltage between the T-Shirt and the lame. When the sabre touches the lame, it works like an antenna and detects the HF-Voltage.

Anyone how knows more details?

Thanks, babinet,

You are closed to my question. How do I wear the blue conductive T-shirt? On skin? under Uniform? or just wear it under Sabre Metal Vest?

[Purple Fencer]

Originally Posted by Wanda

Thanks, babinet,

You are closed to my question. How do I wear the blue conductive T-shirt? On skin? under Uniform? or just wear it under Sabre Metal Vest?

Against your skin, I believe....your body is part of the circuit...

[fencinman89]

Originally Posted by Purple Fencer

Against your skin, I believe....your body is part of the circuit...

Thats shocking!!! or could it be?
-Tre'

[downunder]

Originally Posted by fencinman89

Thats shocking!!! or could it be?
-Tre'

erm no....

[fencinman89]

Thats why i asked....It was more of a joke than anything
-Tre'

[yeoldearmourer]

Your body is part of circuit and act as a captactiors which means your are discharge electric to scroe and yes there is a possible of you being shock. Due to sweat.

[EricS]

This wireless system is actually a copy of a system featured in an old US patent, #4,030,731, which can be found online. Here's the claim of interest:

13. Apparatus as in claim 1 further comprising means for coupling the pulses from a respective pulse generator to the body of the fencer carrying the unit, the pulses from the pulse generator means of one unit being communicated to the receiving means of the other unit by direct contact of the weapon associated with the one unit with the body of the fencer carrying the other unit and by coupling caused by the conductivity of the body of each fencer.

This system used a metal bracelet instead of a conductive T-shirt, but the basic principle is the same.

Apparently the old system had some reliability problems; I'm not sure if they are inherent to the approach or just in the implementation. I heard rumors that the metal bracelet injured one fencer and shocked a few others. This doesn't really make me feel good about wearing a conductive T-shirt...

[prototoast]

Now how does a conductive t-shirt stay conductive? We have enough trouble keeping lames conductive, and they don't contact nearly as much sweat as a conductive t-shirt would. Is there some superior technology at work, and if so, why isn't it used for lames?

[Inquartata]

Sweat is basically saltwater, right? Wouldn't that increase conductivity, instead of decreasing it? Isn't water a pretty good conductor of electricity?

I have never understood the conductive t-shirt thing, either. I mean, it isn't connected to the lame or anything else, is it? It's insulated from the lame by the jacket, plastron and llining of the lame. So what the devil does it do? ( Tim said something about capacitance, why not just use a capacitor in the reelless mechanism? )

Or is this just another way for the manufacturers to sell costly equipment?

[prototoast]

Originally Posted by Inquartata

Sweat is basically saltwater, right? Wouldn't that increase conductivity, instead of decreasing it? Isn't water a pretty good conductor of electricity?

saltwater will increase conductivity in the short term, but in the long term it is also corrosive. When it dries up, the conductivity benefit of the saltwater goes away, but the corrosion doesn't.

[Inquartata]

Does the corrosion proceed so fast that it's necessary to change to a fresh t-shirt during a competition?

[prototoast]

Originally Posted by Inquartata

Does the corrosion proceed so fast that it's necessary to change to a fresh t-shirt during a competition?

Of course not.

[Inquartata]

Then I still don't see what the problem is with sweating in it, conductivity-wise...