January 7th, 2006

ronin

Today we learn about OpAmps.

An Operational Amplifier (op amp, op-amp or opamp for short) is a reasonably complicated arrangement of transistors that can be used for a staggeringly wide variety of purposes, which we will get to in just a second. But first, its schematic symbol:



The Op-Amp has two inputs and one output. Any voltage fed into the inverting input (V-) will appear as an identical negative voltage at the output. Any voltage fed into the non-inverting input (V+) will appear as a positive voltage at the output. (Note that since the op-amp can output plus OR minus the full voltage applied to its inputs, it has to to be fed with not the normal positive voltage and ground, but with positive voltage (Vs+) and negative voltage (Vs-).) If voltages are applied to both the inverting and non-inverting input, they will be subtracted as one might expect: the output voltage will be the voltage applied to the non-inverting input, minus the voltage applied to the inverting input. Thus the opamp can be used as a math circuit, subtracting two signals. Also, since the opamp is exquisitely sensitive to differences in the inputs, it can be used as a very good comparator. But the opamp can also do much more...

Collapse )
ronin

[Fark] Why does the Pentagon hate our troops in Iraq? Again.

A Pentagon study reportedly found that as many as 80 percent of Marines killed in
Iraq from wounds to the upper body could have survived if they had had extra body armor.

"Such armor has been available since 2003, but until recently the Pentagon has largely declined to supply it to troops despite calls from the field for additional protection," The New York Times reported citing unnamed military officials.

"For the first time, the study by the military's medical examiner shows the cost in lives from inadequate armor, even as the Pentagon continues to publicly defend its protection of the troops," the report said


http://news.yahoo.com/s/afp/20060107/wl_afp/usiraqmilitaryreport

No goal. No way out. And lacking the tools to do the job. What they hell are they doing to our troops? - Comment from Fark.com

See also: http://headlinesoldier.blogspot.com/2005/12/rush-limbaugh-loves-our-troops.html

Remember that you voted for this, America.