T&L Publications

Some very high power transmission towers near the airport have a strobe flash on top. No signs of how are powered. Footings are on water.

Would those have a way to contactlessly 'steal' some energy from what I guess is 100KV+ to make them work ? No solar panels on the tower, nothing visible connected to it.

Miguel

Sorry ! Brain fart, wrongly posted on compfusers section; can it be moved ?

as far as moving this post to another catagory, i am not sure how you would do that.. maybe in edit ?

most of them strobes are indeed powered by regular power...i have worked on a few in the past.
most have either 120v or more typically a 220v input..
the tube is typically a 75 - 100 watt coiled tube.
the power to the lamp is way up there..in the range of 5kv for the anode and cathode, the trigger pulse can be as high as 20kv.
the caps inside are almost beer can sized too.

some strobes actually have a switcher power supply. and thus can actually make a xenon tube stay lit for a few seconds at a time. they are not run at full power tho, otherwise the tubes would be worn out in a short time.

have only seen a few led versons..

and some still use the 750 watt mogual based lamps.. these lamps give off more heat then light, but the filiment is very heavy duty. to last about 8 thousand + hrs.

hope this helps ya.

Thanks, dacflyer.
The thing is such power transmission towers carry only megavolts on 4+ feet long porcelain insulators... how is downconverted to supply the strobe ?
Miguel

http://www.dunedindailyphoto.com/photos ... ay02md.JPG

It's not. Refering to your photo:

Only 3 large insulators. Those lines would be the high voltage 3 phase delta.

The 2 faint lines on top cross arm would be ground to attract lightning away from high voltage lines.

The faint line tied to center of tower at lowwer cross arm might be low voltage for lights. Or, power for lights might be in steel conduit in a vertical leg, and through the cement from an underwater cable.

The faint line tied to center of tower at lowwer cross arm might be low voltage for lights. Or, power for lights might be in steel conduit in a vertical leg, and through the cement from an underwater cable.

I too think thats the most likely explanation though I can concieve of an inductive pickup but that would have to put a coil around a cable but I think that would be visable. You can't even bring the voltages on those HV cables close together or they will arc in open air. A step down transformer would be large and obvious. a step down could not fit in a strobe housing due to HV clearance/separation requirements.

"A step down transformer would be large and obvious"
You got that right. On occasion, power companys will run some tests on hi lines(345KV) and connecting terminals.Three phases are dropped from above with wide separators between them to a transformer below for metering purposes. Utility slang refers to these as potential transformers and always the secondary is 120 VAC, no matter what the primary voltage is. The trannys are only used for metering purposes (very light loads) and even at that are about the size of a small SUV. When all safeguards are in place, the completed installation looks like a mini sub station with high fences around it.
Dyarkers got it right. Every lit tower I have been around (hi-line,radio or microwave relay) has it tower lights fed from an external 120 VAC source, and fed thru conduit fastened to the tower structure.

Anybody remember the "Rogowski Coil"?
Me neither, but wiki has one approach:
http://en.wikipedia.org/wiki/Conductor_marking_lights
I suppose strobe circuitry could be powered with this.