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A "thumper" test set applies a high-energy, high-voltage pulse to the cable. Fault location is done by listening for the sound of the discharge at the fault. While this test contributes to damage at the cable site, it is practical because the faulted location would have to be re-insulated when found in any case. [7]
Switch matrices present a unique problem to test system designers as the signal conditioning needs, the frequency range, the bandwidth, and power aspects change from application to application. Test and measurement companies cannot provide a "one size fits all" solution.
A transformer designed specifically for the relevant frequency range must be used. Optoisolators can perform the same task for digital lines but introduce signal delay. In circuits producing high-frequency noise such as computer components, ferrite bead chokes are placed around cables just before the termination to the next appliance (e.g., the ...
An RF switch or microwave switch is a device to route high frequency signals through transmission paths. RF (radio frequency) and microwave switches are used extensively in microwave test systems for signal routing between instruments and devices under test (DUT). Incorporating a switch into a switch matrix system enables you to route signals ...
for AC having a supply frequency of 50, 60 or 400Hz, though the use of other frequencies for special purposes is not excluded. This includes low-voltage installations, as found in most domestic and commercial properties, and extra-low-voltage systems, but excludes high voltage , as found in generation, transmission and distribution networks.
Powering a noise-sensitive SoC or circuit component in a pulsed application with an LDO may well turn out to be a sub-optimal solution: in addition to low conversion efficiency, noise is still present on the supply bias in the form of transients which vary in both frequency and density (frequency of occurrence). [7]
AFCIs are also known to be sensitive (false tripping) to the presence of radio frequency energy, especially within the so-called high frequency (HF) spectrum (3–30 MHz), which includes legitimate shortwave broadcasting, over-the-horizon aircraft and marine communications, amateur radio, and citizens band radio operations. Sensitivities and ...
In both those instances the white wire should be identified as being hot, usually with black tape inside junction boxes. The neutral wire is identified by gray or white insulated wire, perhaps using stripes or markings. With lamp cord wire the ribbed wire is the neutral, and the smooth wire is the hot. NEC 2008 400.22(f) allows surface marking ...