The charger maintenance method

Visual method

Look, capacitor: the more obvious characteristics are that the capacitor contains a certain solution, in the exceedence of the working environment, the capacitor will heat itself to relieve the body and mind can not bear the pressure, some relatively poor quality capacitors will explode to the body can not be found, known as without a trace of small firecrackers, leaving only some small pieces of paper. Resistance: After heating and overload, it will change color or smoke. Of course, the resistance will also explode, explode or part of itself flies away.

Resistance method

Use a digital multimeter to measure the suspected part of the circuit, generally we use a diode file for measurement, that is, short circuit 2 pen, the multimeter will call that file, before measuring resistance we will do some necessary discharge behavior, in the case of confirming that there is no plug in the mains, we use tweezers to short circuit some capacitors, The capacitor will give off sparks and sounds when it discharges. Don't be afraid. Then make our on-road resistance measurements.

Voltage method

Learn to measure voltage is one of the basic skills of maintenance, electric road measurement is more dangerous behavior, we still need to do so when necessary, this behavior is not only our own safety problems, but also due to the operation of accidental damage to the charger possibility is very large, if the charger measurement is broken, we do not feel depressed and sad, very good technicians, Mistakes are made, even by masters. As long as we remember to measure the voltage has a clear purpose, do not blindly charged around random quantity, this is a big taboo.

Substitution method

Substituting means replacing some of the components, and the replacement component may be new, or it may be removed from a working charger. Why do substituting? This method is generally our maintenance into a relative bottleneck, we will have such an idea, replacement is more suitable for specific devices such as: capacitors, integrated blocks and some other devices may be soft damage, for other hard devices, we do not need to consider replacing it

Contrast method

The so-called contrast method, is to find a exactly the same or similar charger we take it as a template, comparison, many aspects to eliminate and reduce the scope of the fault, which includes: resistance method, voltage method, replacement method!

1: Power does not start: plug the power supply, the large capacitor has 300V voltage, unplug the power supply and measure the large capacitor 2 end or 300V voltage does not drop. After discharging the capacitor, replace the starting resistor. Starting resistance in the power input part, resistance value 150K, power 2W,

2: Power does not start: plug in, there is 300V voltage at the two end of the large capacitor, unplug the power, and the voltage of the large capacitor drops slowly. Check whether the circuit board is dersoldered. After the repair welding is completed, replace the 3842 with a new one and power on the test machine.

3: Flashing: First the circuit board repair welding again, again test machine, if it is still flashing, please check the output end sampling resistance. 0.1 euros. 3W power. Connect to the negative extreme of the output line, and replace the resistance with a new one.

4: high output voltage, power-on, voltage is higher than 70 V, charging does not turn the lamp, first repair welding circuit board, again test machine, if the voltage is still high, please replace the photoelectric coupler, again test machine, still high output, replace the 431 reference voltage regulator, again test machine

5: squeak, heat, insufficient charge: power measurement of large capacitor voltage, as long as less than 300V, general capacitor failure, replacement can be,

6: serious fever, please replace the fan.

7: The output voltage is not stable, the circuit board will be repaired once again, after the test machine, and then the output capacitor 63V470UF can be replaced by a new test machine,

8: charging does not turn the lamp, test the data with the detector, and then 358 or 324 for a new trial machine,

9: charging is not stable, sometimes can charge, sometimes can not rush, with the tester to detect the data, and then input and output power line, all new, repair welding circuit board test machine

10: power-on burning insurance: first detect the breakdown of the power tube, if not, all the 4 rectifier diodes are replaced with new, test machine,

11: power-on no output, power-on test machine, large capacitor 2 end has 300V voltage, and slowly decline, first detect the output diode breakdown, repair welding, again test machine

12: power on 2 red lights: power on test machine, no-load voltage is normal, and then 358 or 324 for a new test machine,

13: power-on no output, can start normally, the indicator light is normal, the output line will be replaced first, for the relay charger direct short circuit relay test machine,

14: power flashing light, please repair welding transformer pin, and then test, if still, please check 431, photoelectric coupler, output diodes are short circuit, transformer magnetic core is loose, power input part 10 ohm small resistance is open or replace 3842 test again

15: charging does not turn the lamp, first use the tester to detect the data, generally charge the new battery voltage is not higher than 59.5, charge the battery for about half a year is not higher than 58.8, is normal, higher than this voltage may not turn the lamp

16: output low voltage: repair welding circuit board. Test machine, and then the input and output large capacitor to replace the test machine again

17: low output, hot, if the output voltage is less than 40 V, and the power tube, transformer hot, generally the transformer has a problem,

18: It is difficult to start, sometimes it can be started, sometimes it can't be started, repair the circuit board, post-test machine, if still, please replace the input part of the small capacitor with a new test machine, 50V47UF

19: burn 3842,3842 after the replacement of the test machine to hear a click sound, this is the measurement of large capacitor 2 terminal voltage 300V slowly, indicating that 3842 again breakdown, repair the circuit board, check whether the transformer pin loose or disconnected, output part of the large diode is open, circuit board is broken.

20: The above faults are suitable for the common faults of most single tube circuit chargers on the market. You can consult technical personnel at any time during the operation.