Today’s huge ac grids consist of many separate generators with new ones continually coming online. When a generator is powered down for maintenance or even temporarily disconnected, it must resynchronize upon rejoining the grid, generally by automatic means with manual backup instrumentation in place if needed. The process of synchronizing ac power sources to grid […]
FAQ
User review: Connecting the Tektronix AFG 31000 AWG to the MDO3000 oscilloscope
The new Tektronix AFG 31000 Arbitrary Function Generator is noteworthy in that the Home screen, accessed by pressing the Home button on the front panel, permits the user to choose a Basic or Advanced mode. The Basic mode resembles a traditional AFG, with a library of internal waveforms and menus that permit the user to […]
Measuring Ethernet and WiFi transmissions
The Ethernet computer networking protocol is used in local area networks, metropolitan area networks and wide area networks. While the term is often used to distinguish wired data transmissions from Wi-Fi, both use parallel protocol details, notably 48-bit MAC address and Ethernet frame format. Actually, Wi-Fi is Ethernet over a different medium. There are a […]
Digital caliper, Pt 2: Implementation and extensions
Use of electronics and capacitive-based position sensing have transformed the caliper, a fundamental and essential instrument of precision linear-dimension measurement. Part 1 of this FAQ looked briefly at the basic mechanical, Vernier, and dial-readout calipers, as well as the micrometer. All these mechanical-only embodiments of the caliper were made obsolete within a few years with […]
The difference between attenuation in conductors and optical fibers
Electrical power moves through a conductor when opposing dc or ac voltages are applied at opposite ends. Charge carriers — free electrons or electron holes in semiconductors, ions in electrolytes – migrate toward the opposite poles. Metals, with abundant free electrons, have high conductivity. All conductors are partial insulators and all insulators are, to some […]
Digital caliper, Pt 1: Background and predecessors
Use of electronics and capacitive-based position sensing have transformed the caliper, a fundamental and essential instrument of precision linear-dimension measurement. Making precise measurements across small distances of up to several inches or tens of centimeters is an obvious and fundamental requirement of modern metrology, research, and mass production. But how can that be done accurately, […]
Cathode ray tube vs. flat screen displays in oscilloscopes
Prior to the digital revolution in electronic instrumentation, oscilloscopes displayed waveforms on cathode ray tube screens. Modern digital oscilloscopes universally have flat screens. The flat screen is light, thin, consumes far less energy, and is less expensive to manufacture. All agree that it is a great improvement. The one advantage of CRT technology is that […]
The difference between metal conductors and waveguides
Manufacturers of instrumentation are striving to satisfy the demands of modern electronics which continuously require greater bandwidth. There has been a growing tendency to incorporate waveguides, ranging from extremely small units soldered into printed circuits, to larger devices mounted in enclosures. The natural question that arises is how waveguides differ from ordinary wiring, and why […]
Induction motor vs synchronous: What’s the difference?
All rotary electric motors, ac, and dc, operate because of the interaction of two magnetic fields. One is stationary and is (usually) associated with the motor’s outer enclosure. The other rotates and is associated with the motor’s spinning armature (also called its rotor). Rotation is caused by the interaction between the two fields. In a […]
Analog and digital modulation and modulation measurements
In amplitude modulation (AM), the amplitude of a carrier wave whose frequency remains constant changes in response to the modulating signal. In frequency modulation (FM), it is the frequency of the carrier that varies with the amplitude of the modulating signal. The carrier frequency deviates more when the modulating signal amplitude is higher. There are […]