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Electrostatic flat indicator

Cheap! Easy! Fun!
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Tire punctures would not be so bad if it were not for the fact that they are generally not detected until the tire is flat. What if you could detect immediately when your tire had been punctured?

The Electrostatic Flat Indicator operates on the principle of charge seperation. If the interior of the tire carries an electrical charge, there is no quick way for that charge to escape. The EFI is a small box the size of a Zippo lighter which is battery powered and attaches at the site of the fill valve. It imparts a charge to the tire interior then monitors it. As long as the charge in there is relatively stable the EFI sends a wireless signal to the detector on the dash which shows a green light. The detector has 8 LEDS: a green and a red for each tire. Vehicles with more tires can add additional dash modules.

A sudden drop in the interior charge means that the tire has been breached by something conductive. The EFI sends a different signal which is displayed as the red alarm light on the dash detector. Each of the 4 EFIs is on a different channel, so the detector can display which tire is out. If the detector finds no signal from a tire, it blinks to indicate that the EFI is gone or its battery dead.

The EFI will detect punctures from metal objects but not from the rare nonconductive objects (eg bone fragment). In tight traffic the detector might pick up signals from the EFI on other cars if they happened to share channels, but this would not be obvious unless the other car had a puncture.

Best of all, this is 100% aftermarket, with no mods needed to tire or car!

bungston, Jun 27 2005

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       I thought automatic flat detection was already Widely Baked? (Don't know if it's electrostatic or not.)
DrCurry, Jun 27 2005
  

       You have a couple of pints of negative charge in your tyre, and if you run over a nail, the negative charge is conducted out of the tyre via the nail. Is that right?
angel, Jun 27 2005
  

       Right.
bungston, Jun 27 2005
  

       What's the risk of false positives?
waugsqueke, Jun 27 2005
  

       Stunningly bad science, but what the hell.
angel, Jun 27 2005
  

       How would you get this electrical charge into your tyres?
Prolixed, Jul 15 2005
  

       Errrr, unless the tyre has been fitted with an inner-tube, won't the charge leak away through the wheel? And in any case, won't the charge leak away in a few seconds or minutes? Rubber is an insulator, but nothing is that perfect an insulator.
Basepair, Jul 15 2005
  

       How would you monitor the charge on the tires interior? If you had a detector fixed to the rim, then, every time you hit a bump, the detector would come closer to the tires surface, causing a spike in detected voltage. Would also cause a drop after the tired bounced back up.   

       Insulators are insulators because they don't allow electron movement through or across their surface very well. And, you would have the inside of the metallic rim within the tire chamber. Would the idea still work considering this? I suppose you could put an insulator on the inside of the rim.   

       What if you charged the air within the tire and monitored the current required to keep the air charged to that voltage. If it changed much, then you would have air leaking out, giving roughly the same surface area for the charge to dissipate (the tire) but less air volume, causing a change in charge required. This wouldn't do too well since you would most likely make things like ozone from the high voltage. Ozone is very corrosive to rubber.   

       comments?
nomel, Jul 15 2005
  

       Though I am completely ignorant, it had been my assumption that the metal parts of the fill valve were in continuity with the charged tire interior. Although a conductor, because this metal is surrounded by the plastic / rubber valve it cannot bleed off the charge. It can, in my hypothesis, be used to add to then monitor the charge.
bungston, Jul 15 2005
  
      
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