Voltage indicator: advantages and disadvantages

A small and fairly simple device designed for visual control over the voltage in an AC circuit is called a "voltage indicator". Its use is advisable in those cases where there is no need for accurate measurements, it is only necessary to know about the presence / absence of voltage. They perfectly cope with their task in production and at home, significantly reducing the time of repair work. You can not forget about security in this matter. Such devices often save a person's life.

There are various modifications of indicators, but they all work on the same principle. As an example, we can consider the standard scheme of a simple indicator. It consists of a low-current neon light bulb and a current-limiting resistor, connected in series. The whole circuit is insulated. One end of such a device concerns a conductor that is energized. In order for the neon light to light up, it is necessary to create a potential difference. This can be done by touching the other end of the device with the hand. Using such a voltage indicator, you can quickly investigate, for example, the control circuit of the relay circuit and find a malfunction. It should also be taken into account that if the circuit is powered by an AC source with uninsulated neutral, then the indicator will light only when working with the phase conductor.

The above-described voltage indicator has one major drawback. It is not safe to work with, and if the limiting resistance is broken, you can get an electric shock. The most safe are the devices manufactured by the industry especially for these purposes. They work on the same principle, but the potential difference in this case is created by touching the second part of the device to a zero or phase conductor. They consist, respectively, of two parts, but when measuring you do not touch the contact parts of the product.

Such voltage indicators are compact enough and convenient in operation. It should also be noted that they are reliable and easy to operate. Devices differ in measuring range. There are measuring rods that can indicate the presence of high voltages above 1000 volts.

The active part of such a device is located at the end of the rod, which can be several meters long. It all depends on the nominal voltage to which its operation is designed. When working with such a device, it is necessary to wear insulating gloves. The measurement in such circuits is performed by well-trained personnel.

After the end of the measuring rod touches the conductor, the indicator will indicate the presence or absence of voltage. Its level can be estimated approximately by filling a special scale, which is located directly on the measuring instrument. This is the so-called digital voltage indicator, which allows you to visually assess the potential of the measured circuit.

As you can see, voltage indicators are widely used in production and in everyday life. They are diverse in their design and cover a wide range of measured voltage.