Diodny Bridge is the two-half-period rectifier of alternating current. It serves for transformation of electric current of variable polarity to current with constant polarity of tension. Any diode bridge consists of four diodes connected according to the same scheme. Diodny Bridge can be executed from the separate elements mounted in any available way or in the form of ready assembly. It is one of key nodes of all power supplies of a direct current working from alternating current. One of the frequent reasons of not operability of power supplies is failure of the diode bridge. Therefore if the nobility how to check the diode bridge, it is possible to reveal quickly this type of malfunction and to make necessary replacement of details.
It is required to you
- The tester allowing measurement of resistance in the range of 100-1000 ohms.
Instruction
1. Prepare the diode bridge for check. Open one of connections of diodes among themselves. If connections are carried out by means of soldering, unsolder two diodes in the place of their connection. It is necessary for an exception of influence of difficult malfunctions (breakdown at once of several diodes) on results of testing. If the diode bridge is executed in the form of uniform assembly, preparation for check is not required.
2. Prepare a tester for work. Switch it to the mode of measurement of resistance with the maximum value of 1000 ohms. Check operability of a tester, nakorotko having closed contacts of probes. The displayed value of resistance has to be equal to zero.
3. Check operability of diodes. Measure resistance of each diode separately in two directions. Connect tester probes to diode conclusions. Take readings of value of resistance. Trade probes places. Again take readings. The efficient diode has to have resistance several hundreds of ohms in one direction (depends on semiconductor material - silicon or germaniye) and infinite resistance in another. If the diode has low resistance at its measurement in both directions, so the diode is punched nakorotko. If in both directions the diode has infinite resistance, so the diode is punched on break. Diode bridges in the form of assemblies are checked similarly. At their check because of breakdown at once of several diodes, the efficient diode can be revealed as faulty. But it changes nothing as it is necessary to replace all assembly.