Voltage indicator - sensors Ancient spell...
Voltmeter analog, that is, analog voltage meter, the longest present on the market a kind of pointer to a value of voltage. Previously, each voltage indicator, from the simple meter of the diffuser in the receiver and magnetofonach blade, after the high-class laboratory equipment was equipped in the so-called "system" measurement. The principle of operation of such element is quite simple: the current flow through the light, thin coil, connected with the Board, causes it to rotate relative to the permanent magnet. The rotation angle depends on the voltage, and this, in turn, a certain coil resistance is proportional to the value of the voltage at its terminals. So we see that the same measuring device, depending on the connected (or no) additional resistors, can be used as a ammeter and voltmeter.
Modern applications of analog devices
Today, despite the universal availability of digital devices and their low prices, still willing to apply the use of voltmeters and amperomierze wskazówkowe. As an example may serve the device, stylized old – lampowe audio amplifiers are the best proof of the enduring popularity of traditional indicators. Also a simple power supplies, including laboratory, are often not typical of the LED display, but the analog voltage indicator. Cheap electrical devices of everyday use, such as car charger, also use repeatedly with sensors wskazówkowych.
The voltage, that is, if you can "see through walls"?
Yes! Of course, if we mean the detection of hidden in wall wires or metal elements. For this purpose, voltage detectors, in a position a small distance, to detect an electrical wire in which a current flows or breaches of the magnetic field caused by metallic objects (e.g. rebar). For installers and DIY excellent use will also "długopisowy" voltage indicator, which makes it easy to determine the phase wire in the electricity network.