One of the criteria for the normal operation of electronic devices is a stable power supply. A change in the voltage in the supply network can critically affect the operation of a household or other appliance. Semiconductor elements provide additional opportunities for developers of various devices. Unfortunately, they are sensitive to operating conditions and require careful treatment. One of the devices that can protect electronics from damage during voltage surges or a high level of impulse noise in the mains is a surge protector. It does its job well and extends the life of the appliances.
Let's mentally imagine the supply voltage and consider how different types of consumers affect its parameters. And how does a surge protector save an electronic device from damage? Ideally, the supply voltage is a sinusoid. It is constant in its effective (amplitude) value and frequency. Unfortunately, when powerful consumers of electricity are turned on, various kinds of interference occur,which can damage sensitive devices.
In everyday life, such “noisy” electrical appliances include vacuum cleaners, refrigerators or air conditioners. That is, where asynchronous or other types of motors operate, distortions will necessarily occur in the supply network. This is due to sparking on the brushes or for some other reason. Even the operation of an ordinary electric razor can disrupt the operation of, for example, radio receivers. In other words, when working with an inductive load and with a short break in the electrical circuit (as in the case of brushes in an electric motor), interference enters the supply network. They are short-term pulses of increased voltage. The network filter, in fact, was created to deal with such anomalies.
But it's not just electric motors that are the problem. Another type of highly “noisy” devices includes modern electronic devices themselves: televisions, tape recorders, computers, etc. It turns out that the surge protector is able to protect electronics from damage, which itself creates unfavorable conditions for its work. The fact is that modern devices incorporate switching power supplies, the operation of which is associated with a frequency of 1000 Hertz or more. Since there are transformers at the input of such devices with a certain inductance, interference occurs.
They are easy to see with an oscilloscope. You can assemble a small surge protector with your own hands to make surethe effectiveness of its application. To do this, it is enough to create an inductance that will prevent the passage of high-frequency interference into the supply network. To do this, simply wind a certain number of turns of wire, for example, a PEV brand, on a ferrite ring and solder it in series into the supply circuit for your computer. As the inductance (number of turns) increases, you will be able to see on the oscilloscope that the noise gradually disappears.
Currently, there are a large number of network filters that are designed specifically to work with various types of load. A good example in this case is the Pilot surge protector, which has excellent performance.
