ข้อมูลทรัพยากร

เนื้อหาย่อ : Most of us who use oscilloscopes learned to operate them in much the same way we learned to operate our televisions-with no clear understanding of the controls we adjust or the signals that are traced across the screen. Consequently, we acquire a repertoire of mea- surement ''skills'' that does not grow at the same rate that we assim- ilate technological tidbits of knowledge in our daily pursuit of a ca- reer or diversion in electronics. Many technicians and hobbyists are accustomed to using os- cilloscopes, but only a small percentage of users ever are well- enough acquainted with the instrument to use it to full advantage. If there were some way to restrict our test-equipment complement only to an oscilloscope without limiting the measurements we want or need to make, we might profit from this ''disadvantage." A per- son familiar with a multirange ammeter, for example, might never have the incentive required to ''discover'' that he or she can mea- sure current in a line indirectly by installing a one-ohm resistor and easuring its potential with a voltmeter. Adequate instruction in accredited schools is the ideal answer. However, few of us have the time or inclination to return to the lassroom, even if it could result in a substantial improvement in our knowledge and skills. There is always the printed word, of course. But if a book is to be an effective teacher, it must be written with words and based on concepts that are within the grasp of the reader; the reader must possess the background assumed by the au- hor. Obviously, no book can impart information to all readers with equal efficacy or lucidity. Some readers will understand by infer- ence what the author has neglected by oversight, while others might have difficulty comprehending issues that seemingly have been belabored. It is our conviction that a full understanding of waveforms is a rerequisite to a good appreciation of the oscilloscope, because it is, above all, an instrument for analyzing and measuring waveforms. Probably we're not the first to tie waveforms and oscilloscope dy- amics together-the appropriateness of the ''marriage'' is ines- capable. But to our knowledge no other authors have managed to do it, and it's not particularly surprising; there are so many impor- nt preliminary elements to cover in both fields that one subject, al- st by necessity, suffers while the other is presented in some co- herent scheme. Both subjects-oscilloscopes and waveforms -are