Lock in amplifier
From emboxit
- http://www.phys.utk.edu/labs/modphys/Lock-In%20Amplifier%20Experiment.pdf
- http://hades.mech.northwestern.edu/index.php/Phase-Sensitive_Detection
- http://www.thinksrs.com/downloads/PDFs/ApplicationNotes/AboutLIAs.pdf
- http://electron9.phys.utk.edu/optics507/modules/m10/tn1000.pdf
- http://www.google.gr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&ved=0CFoQFjAD&url=http%3A%2F%2Fcourses.washington.edu%2Fphys431%2Flock-in%2Flockin.pdf&ei=LFEzUIaABcTc4QT-tYH4Ag&usg=AFQjCNEhKpT_CIjANxjl1wQHZbyxzWjgMQ&sig2=k7g7jQfik1aMrT_51QsFaw
- http://www.google.gr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=18&cad=rja&ved=0CF4QFjAHOAo&url=http%3A%2F%2Fservv89pn0aj.sn.sourcedns.com%2F~gbpprorg%2Fzine2%2Fmisc%2FSimpleLockInAmplifier.pdf&ei=81IzUJzZMafb4QT5_YHQBA&usg=AFQjCNEbp4ACJdh3hn1mYO34V-kws_-rlg&sig2=xzfyF3yZ-sJvBu73Dz4VxQ
- http://www.edn.com/design/analog/4312612/Compact-four-quadrant-lock-in-amplifier-generates-two-analog-outputs
- http://www.ebay.com/sch/i.html?_nkw=lock-in+amplifier
- http://www.google.gr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CEkQFjAA&url=http%3A%2F%2Fservv89pn0aj.sn.sourcedns.com%2F~gbpprorg%2Fzine2%2Fmisc%2FSimpleLockInAmplifier.pdf&ei=sFgzUN7HH6Pj4QSX0IGwDg&usg=AFQjCNEbp4ACJdh3hn1mYO34V-kws_-rlg&sig2=SISHCEnHQmrWgn127CP8Og
Fig. 3. A popular experiment to demonstrate how lock-in detection can recover a small signal buried in noise. When the LED is close to the photodetector, the signal is large and can be seen directly on the oscilloscope. When the LED is farther away, the signal is no longer visible on the oscilloscope, but is easily detected with the lock-in.
