The largest deviation from the nominal output voltage (230 V or 400 V, depending on the number of phases), which the regulator allows when operating in the normal input voltage range (see above). The smaller this deviation, the more efficiently the device works, the more accurately it adapts to “changes in the situation” and the less voltage fluctuations the connected load is exposed to.
When choosing for this parameter, it is worth considering first of all how demanding the connected devices are for voltage stability. On the one hand, high stability is good for any device, on the other hand, it usually means a high price. Accordingly, it usually does not make sense to buy an advanced stabilizer for an unpretentious load like light bulbs and heaters, but for sensitive devices like audio systems or computers, it can be very useful.
The type of voltmeter provided in the design of the stabilizer, or rather — the type of scale used by this device. This
voltmeter itself allows monitoring of voltage — usually both at the input and output — which facilitates control over the stabilizer's operation. For this purpose, two separate scales are most often provided, but there are also "single" voltmeters with a switch to choose between input and output voltage. As for the type of scales, the following options are available:
— Analog. Analog voltmeters are equipped with a traditional type of scale — with divisions marked on it and a needle. They are simpler and cheaper than digital ones, but less accurate — even in the most precise devices, the error in readings can be 5-10 V just due to the peculiarities of reading information from such a scale. In some inexpensive models, analog voltmeters serve more as general indicators rather than precise instruments. At the same time, for most everyday tasks, such accuracy is quite sufficient.
— Digital. In such voltmeters, the role of the scale is played by a digital
display, where voltage values can be displayed with an accuracy of up to a volt — this is the main advantage of this option over analog. The drawbacks include the complexity and relatively high cost of digital indicators. Moreover, such high accuracy may be critical in the professional field, but in everyday life, it is not
...always necessary. Accordingly, in inexpensive low-power stabilizers, a digital voltmeter is often more of a marketing ploy than a real necessity.
