One of the basic elements in modern electronics is a diode. It is used in circuits where AC rectification is needed, and is used in almost all household appliances. You can find it on a TV, computer, refrigerator, tape recorder, etc. It is also widely used in industrial electronics, is part of the circuits that control technological processes. Powerful power diodes are used in semi-controlled thyristor converters. On the basis of the diode, the so-called Hertz circuit was assembled, which was called the diode bridge. The connection of diodes in a bridge circuit made it possible to rectify an alternating voltage and convert it to a pulsating one, which can then be stabilized and rectified using voltage stabilization circuits and capacitors. As a result, a constant voltage can be obtained at the output of such a device.
During the time of Leo Hertz, it was problematic to use a diode bridge, since diodes at that time were tube diodes. Putting four lamps on AC rectification at once was at least impractical, at that time they were very expensive. The situation changed dramatically with the advent of semiconductorappliances, they are much more compact and cheaper.
Assemble diode
bridge can be done by yourself, for example, for your own home laboratory. To do this, we select four diodes with a permissible reverse voltage of 400-500 Volts. We connect the cathodes of one pair of diodes together - this will be the positive output of the bridge. We also connect the anodes of the second pair together - this, respectively, is a negative conclusion. Now we combine two pairs into a bridge circuit, the remaining two outputs can be supplied with alternating voltage. At the output of the diode bridge, we solder the polar capacitor and, parallel to it, the discharge resistance. It turned out a diode bridge that can be mounted on a desktop and connected through a variable high-resistance to the mains. The output voltage of such a device will be regulated from zero to the amplitude value of the supply network, which is very convenient for powering low-power circuits during commissioning or for creating a reference voltage.
Also, the bridge circuit is used in the car, here the so-called generator diode bridge is used. It serves to convert the alternating voltage that the generator produces into a constant voltage that is used in all vehicle devices. Constant voltage is also needed to recharge the car battery. The failure of even one element of the diode bridge leads to unstable operation of the entire circuit.
DC welding also requires the use ofdiode bridge. In this case, diodes of greater power than in a car are used, and with a large allowable reverse voltage value. The diode bridge for the welding machine can be assembled independently using powerful diodes. The class of diodes is selected depending on the supply voltage received from the welding transformer.
