Category Archives: signal

Low Tech High Safety and the NYC Subway System

The year is 1894. You are designing a train system for a large city. Your boss informs you that the mayor’s office wants assurances that trains can’t have wrecks. The system will start small, but it is going to get big and complex over time with tracks crossing and switching. Remember, it is 1894, so computing and wireless tech are barely science fiction at this point. The answer — at least for the New York City subway system — is a clever system of signals and interlocks that make great use of the technology of the day. Bernard S. Greenberg …read more

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Posted in Featured, interlock, new york, nxsys, nyc, Retrotechtacular, safety, signal, subway, train, transportation hacks | Leave a comment

Cut Through The Noise, See Tiny Signals

An oscilloscope is a handy tool for measuring signals of all kinds, but it’s especially useful if you want to measure something with a periodic component. Modern oscilloscopes have all kinds of features built-in that allow you sample a wide range of signals in the hundreds of megahertz, and make finding and measuring your signal pretty easy, provided you know which buttons to push. There are some advanced oscilloscope methods that go beyond the built-in features of even the best oscilloscopes, and [AM] has a tutorial on one of them.

The method used here is called phase-senstitive detection, and allows …read more

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Posted in detection, noise, oscilloscope, phase, sensitive, signal, tool hacks, trick | Leave a comment