Tip 1: How to check a diode bridge

diode bridge full-wave rectifier is AC.It serves to convert electric current into a current of alternating polarity at a constant polarity voltage.Any diode bridge consists of four diodes connected in the same circuit. diode bridge may be formed from separate elements, mounted by any available means, either as a finished assembly.He is one of the key components of DC power supplies, operating on AC power.One of the frequent causes of inoperability of power sources is precisely the failure of the diode bridge well.Therefore, if you know how to check a diode bridge , you can quickly identify the type of fault and make the necessary replacement parts.
you need
  • tester, allowing the measurement of resistance in the range of 100-1000 ohm.
Guide
1
Prepare diode bridge to checkout.Open the one of the connections between the diodes themselves.If the connection is made by soldering, Unsolder two diodes in place of their connection.It is necessary to eliminate the influence of complex fau
lts (breakdown of several diodes) on the test results.If a diode bridge formed as a single assembly, preparation for the verification is not required.
2
Prepare tester to work.Change the mode to measure the resistance with a maximum value of 1000 ohm.Check the tester circuit closing contact probes.Displayed resistance value should be zero.
3
Check the diodes.Measure the resistance of each diode separately in two directions.Connect the tester probes to the terminals of the diode.Read the resistance value.Change probes places.Again, take the readings.Workable diode should have a resistance of several hundred ohms in one direction (depending on the semiconductor material - silicon or germanium) and infinite resistance at the other.If the diode has a low resistance when measured in both directions, then the diode probit circuited.If both directions of the diode has infinite resistance, then an open diode is broken.Diode Bridge s in the form of assemblies tested similarly.When they check for the breakdown of several diodes, diode-working can be identified as faulty.But this does not change anything, because the need to replace the entire assembly.

Tip 2: How to check a diode bridge

Every motorist knows that the source of electrical current is used in the car battery and alternator.But not all understand that AC is not suitable for operation of the vehicle and its need to "straighten out".For this purpose, a diode bridge is used.

By building this circuitry is designed for converting a car from AC to DC.Diode bridge consists generally of six diodes mounted on the housing of the generator.This extension is called a full-wave in electrical engineering.

Depending on the operating conditions of the car diode bridge can fail sooner or later declared by the manufacturer term, but somehow all the details of wear.This most often happens when moisture gets into the generator (washing cars, crossing water obstacles), or in the winter time, when "Booster" from other car owners confuse inexperienced polarity of the wires.If the diode bridge fails, the vehicle battery does not get recharged, or, conversely, recharges, which leads to electrolyte boiling.

Check diode bridge yourself best with a test light (carry), or tester.For completeness, it is desirable to use the verification in two ways.First, connect to the negative terminal of the battery plate diode bridge (also minus), which is pressed against the body of the generator.Then connect one end of the carry to the positive terminal of the battery.Free end carrying touch a terminal with extra output diodes bolt positive terminal and the connection points of the stator winding.In all cases, the lamp shall not light.If it lights up, then punched a diode bridge.

The next step is to be verified independently on a diode bridge open.To do this, change the connection minus the diode bridge plate with the negative terminal of the battery to the plus, carrying one end is fixed to the "minus" battery and carrying free end plugs into the same points as before.In this case, the lamp should burn bright light.If it does not light up - at some of the findings there is a break in the chain of diode.

With the tester diode test is the following: exhibit mode "proring" semiconductors with 1k limit and start "prozvanivat" each diode.If the diode is good, the value is one way to be 400-800 ohms, and in another - infinity.Car owners who know how to handle a soldering iron and tweezers, can easily come into disrepair vypayat diode and replace it with a new one.All replacement surgery takes less than an hour.

Note
Avoid verify that the diodes by connecting them through bulbs.Current flowing through the diode may exceed the maximum value allowed for the diodes of the series and it will be disabled.
Helpful Hint
can conduct a quick check of the diode bridge for fault by measuring the resistance in both directions between its outputs.The bridge has to pass a current in one direction and not to miss another.Non-compliance of this condition is the fault of the diode bridge.However, its implementation does not mean that the bridge is OK.
Sources:
  • as switching bridges

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