Re: Infrared LED brightness
 

1)
the only situation when sixwheeledbeast's statement is true,is bipolar transistors PIN to PIN direct connection due to transistors electrical characteristics misfit
is not the case here because base pin have a large resistor ( 4.7 k ) and colector resistors 110 ohm and this make the equilibrium between transistors
2)
@ woody14619
resistor notation is 220R ----> 220 Ohm, 2R2---> 2,2 Ohm, etc
220 R is noT 220 miliohm

55 miliohm is very close to short circuit or high power FET transistor on resistance, with this value is like direct apply battery voltage on led. for sure is not real case.

without specs i say the ir led on n900 can handle 100 mA pulsed current and the resistors can be replaced with a lower value. the problem is low voltage in transistor's "base" combined with low hFE ( 80 typical for digital transistors ) ----> low base current -> low colector current ( resulting 2 transistor needed ) .
a transistor with hfe = 80 & 1,8 V Vout of CIR output ( not sure ) can handle ~ 20 mA in cold weather
far lower for high peak current needed for "mall tv fun shutdowner"