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projekte:dvdlsm:start [2021/02/07 15:56] – [Sample Preparation and Imaging] thastiprojekte:dvdlsm:start [2021/02/07 22:25] (aktuell) – [Laser Diodes, Lens and Actuators] thasti
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 ==== Laser Diodes, Lens and Actuators ==== ==== Laser Diodes, Lens and Actuators ====
-The OPU houses two laser diodes. As this is just a DVD/CD reader, the lasers are not very powerful but provide sufficient power for microscopic applications. The (red) DVD diode starts laser operation above approx. 60 mA and requires about 2-2.5 V of forward voltage. Its polarity can be easily determined by measurements.+The OPU houses two laser diodes. As this is just a DVD/CD reader, the lasers are not very powerful but provide sufficient power for microscopy applications. The (red) DVD diode starts laser operation above approx. 60 mA and requires about 2-2.5 V of forward voltage. Its polarity can be easily determined by measurements.
  
 The primary lens is positioned using electromagnetic actuators. These come in the form of three coils, which tilt or move the coil proportionally to the current flowing though them. Their polarity and required full-scale DC actuation current can be easily found by using a lab power supply. The primary lens is positioned using electromagnetic actuators. These come in the form of three coils, which tilt or move the coil proportionally to the current flowing though them. Their polarity and required full-scale DC actuation current can be easily found by using a lab power supply.
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 It was conjectured that the smaller inner quadrants were responsible for the low-sensitivity outputs, while the outer segments would produce a large amplitude (due to their larger light collection area). It was conjectured that the smaller inner quadrants were responsible for the low-sensitivity outputs, while the outer segments would produce a large amplitude (due to their larger light collection area).
  
-In a second reverse engineering session, the exact pinout was determined by means of selective illumination: For a given test, two IC output pins were compared using two DVMs, and an aperture was slowly moved along the surface, either vertically or horizontally. This would in a change of the output voltage for one of the outputs slightly earlier than for the other one. In this way, the positional relationships between all output pins could be resolved, forming a final assignment of diode quadrants to output pins.+In a second reverse engineering session, the exact pinout was determined by means of selective illumination: For a given test, two IC output pins were compared using two DVMs, and an aperture was slowly moved along the surface, either vertically or horizontally. This would in result a change of the output voltage for one of the outputs slightly earlier than for the other one. In this way, the positional relationships between all output pins could be resolved, forming a final assignment of diode quadrants to output pins.
  
 {{:projekte:dvdlsm:pinout_bg.png?800|}} {{:projekte:dvdlsm:pinout_bg.png?800|}}
projekte/dvdlsm/start.txt · Zuletzt geändert: 2021/02/07 22:25 von thasti

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