> isn't the standard 10 miliamps per channel?
Originally 2mA, then 10mA.
As JR says, worst-case is 48V/3.4K or 14mA. You should not smoke if a shorted mike or cable sucks 14mA.
Of course a shorted Phantom load is probably stupid. We need to get some power to the load. The nominal 10mA spec will drop 34V in the 3.4K, leaving 14V for the mike.
At least one version of AKG414 is a 2mA current limiter to a 9V regulator. It will never pull more than 2mA, and does not care a bit if the raw "48V" supply is as low as 16V.
Another class of mike uses the 48V as capsule bias. To keep a decent voltage at the capsule despite the 3.4K, current draw for the amplifier must be quite low, like under 2mA (which is why the original spec assumed 2mA).
Another low-price class of mike is liable to do ANYthing that "works" on most inputs found in Banjo World. Your protection here is the 3.4K resistance in your board, and the concept that pulling much more than 10mA is self-defeating for the mike designer.
> 48v and 250 ohms... 0.2 amps
I had a self-designed system like that. 36V, 470 ohms 2 Watt load. As Phantom became more common I had to be careful not to let wires get mixed up. Perhaps fortunately, I often ran it in stuff that didn't look at all like mike-wires: CAT5 cable, speaker cable, intercom wire, magnet wire.
