I have PHP errors redirected to log file. Only for WP installation so this definitely doesn't come from somewhere else. This is what started to come up recently (this is all of them, not cut):

[22-Sep-2010 14:30:41] junk after document element at line 2, column 0
[22-Sep-2010 16:17:08] junk after document element at line 2, column 0
[22-Sep-2010 17:19:42] junk after document element at line 2, column 0
[22-Sep-2010 18:30:19] junk after document element at line 2, column 0
[22-Sep-2010 20:19:23] junk after document element at line 2, column 0
[23-Sep-2010 14:51:40] junk after document element at line 2, column 0
[23-Sep-2010 15:54:33] junk after document element at line 2, column 0
[23-Sep-2010 17:23:02] junk after document element at line 2, column 0


This doesn't really look like PHP error (function blah-blah failed at line x), they are very infrequent and don't seem to be tied to page loads (maybe to some cron event?) and there hadn't been any major configuration changes in months other than keeping plugins up to date and one or two new ones (days before this started).

Googling results are mostly about XML parsing... Of which WP probably does plenty (feeds, updates, what else?..) but how to pinpoint what is going wrong?

This has me really puzzled.


Question: is this possible: Amps feed joining a Regulated V line
Answer: I'm afraid Electricity Doesn't Work That Way. A linear regulator is basically a resistor that varies its resistance based on the load drawn, to always keep a consistent voltage. In parallel with that you've put some resistors (and note, multiple parallel resistors are equivalent to one resistor with 1/nth the resistance).

What will actually happen in your circuit is this: if the load is large, current will be drawn via your extra resistors until the voltage across them is such that the side closest to the load is at the voltage provided by the voltage regulator. Any additional current will be drawn through the voltage regulator. Together, your resistors and the voltage regulator will dissipate exactly as much waste power (and heat) as a regulator alone would.

If the load is small, the voltage across your resistors will be small, and the voltage on the output will thus be large - up to the input voltage minus the diode's forward voltage, at no load - and the linear regulator will shut off completely, vainly trying to reduce the voltage by limiting the current through it.

Thus, what you've created is a sort of "lower bound voltage regulator", which provides a voltage between the input voltage and the set voltage at low currents, and exactly the set voltage at high currents, up to the limit of what your regulator plus resistors can dissipate.

There are well established solutions for converting voltages at high current with low waste, called switching regulators. They work by repeatedly charging up an inductor - a coil of wire - and discharging it into a capacitor, which serves to convert from one voltage to another with minimal waste.