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Is there any easy and safe way to convert the high voltage AC (60Hz, 10kV, such as the voltage on the overhead line) to 5V DC that can be used to power up a micro controller (around 1W power)? We do have a ground in the AC system. What is the easiest way? Are there any COTS products or components available?

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    \$\begingroup\$ You'd need a very large transformer, and unless you are fully training in working with very high voltages, probably immortality as well. Such high voltages will kill you before you know it if you get it wrong. \$\endgroup\$ May 19, 2015 at 20:02
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    \$\begingroup\$ My thinking is that if you have to come here and ask, you aren't working for the power company or somewhere else where you would be qualified to do such a thing, and messing around with the HV lines will probably just get you dead. \$\endgroup\$
    – I. Wolfe
    May 19, 2015 at 20:15
  • \$\begingroup\$ COTS device is a "pole pig" \$\endgroup\$ May 19, 2015 at 20:43
  • \$\begingroup\$ YouTube has a number of videos showing what 10kV+ at high current can do to people. I'm a professional EE and would not do a job like this no matter what you paid me. \$\endgroup\$ Jun 28, 2017 at 12:20

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Anything that requires connection to a 10kV AC line is potentially very, very lethal but, given that this CAN be done correctly and safely (i.e. employ someone trained to do so) then you can create a capacitor dropper that feeds a regular mains (110V or 230V) isolating transformer. I'm suggesting this because the power requirement is so small and using a 10kV primary transformer is going to be a b*tch of a lump in size!

Caution - make sure the capacitor dropper has very conservative ratings on the capacitors and include a fuse that can break the circuit should something go wrong at voltages up to 15kV. Use several capacitors in series to give a higher voltage rating and observe creapage distances on circuit boards (if used) and apply liberal air gaps.

In case you intend to try and rob an electricity company of a little power please justify your application.

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  • \$\begingroup\$ Isn't robbing the electricity company justification enough ;) \$\endgroup\$
    – brhans
    May 19, 2015 at 20:28
  • \$\begingroup\$ It might be LOL \$\endgroup\$
    – Andy aka
    May 19, 2015 at 20:32
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The current you need is low, you could wind your own coil and tap power by placing it within the magnetic field of the overhead line. You may not have to get too close to the 10KV line (that depends on how much current is passing down the 10KV line and consequently the magnetic field strength).

But consider two things: You don't have to touch a 10KV line to get an electric shock from it, just getting close to it can be enough for it to arc across to you and electrocute you.

And be prepared for the high voltage produced by the coil. If the overhead line belongs to someone else and not you and if you don't have permission to use the electricity then technically what you are doing is theft.

I heard of a story in the UK where someone was caught taking electricity in this way (by magnetic induction) and they were prosecuted for it.

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  • \$\begingroup\$ Assume we want to transfer power for larger distance within our farm field. It is very expensive to lay Electric cable. So can I convert DC voltage to very high voltage and then covert back to low voltage? so that large diameter cable is avoided? I looked at lot of boost converters in ebay/Ali express for USD 1 or less that convert DC low voltage (such as 12V DC) to very high voltage say 10KV. But I searched for high voltage to low voltage converters (10KV to 12V) and could not find. Any such low cost converted? \$\endgroup\$
    – Rajesh
    Apr 9, 2019 at 17:14

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