Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.

  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

6: DC and AC Bridges > 6.27 - Oscillographic Recorders

6.27 OSCILLOGRAPHIC RECORDERS

Oscillographic recorders are essentially X–T recorders and are characterized by high sensitivity, reasonably good frequency response, and ease of operation. The heart of an oscillographic (also known as optical oscillographic) recorder is the moving coil galvanometer (mcg), which is built in a miniaturized form. As shown in Fig. 6.35 a small coil is held in a uniform magnetic field by a thin suspension ribbon. A constant current flowing through the coil can produce a torque that is related to the current, the magnetic field, number of turns in the coil, the coil geometry, and its position relative to the magnetic field. A small mirror is attached to the galvanometer suspension. A light beam hits the mirror and gets reflected from it onto the recording medium, which is usually a photo-sensitive material (not shown in the figure). As the coil rotates, the reflected beam will swing through an angle ?. If the distance between the mirror and the recording medium is R, then the deflection recorded ‘y’ is of the form y = R tan ?. Figure 6.35 shows the galvanometer arrangement for an optical oscillograph.


  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free 10-Day Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint