Switch power source is groovy 4 big trouble and overhaul method

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  • source:DELENO CNC Machining
Switch power source is the component that all sorts of electron equipment cannot be short of surely, the technical index that its function actors or actress bad matters to electronic equipment directly and whether ground of on the safe side works. Because interior of switch power source is crucial,the job is in yuan of parts of an apparatus condition of high frequency switch, power comsumption is small, change rate is high, and bulk and weight have linear power supply only 20% , 30% , at present it already became friend the mainstream product of regulated power supply. Electronic equipment is electric the overhaul of breakdown, act on from the principle with arrive easily difficult, basically be first from power source proceed with, after deciding its power supply is normal, undertake the overhaul of other position again, and power source breakdown takes electronic facility the great majority of electric breakdown. Power source of reason understanding begin works basically principle, be familiar with its to maintain skill and common breakdown, be helpful for shortening electronic equipment corrective maintenance time, raise individual equipment to maintain technical ability. 1.

Without output, insurance canal is normal power source of switch of specification of this kind of phenomenon did not work or entered protective state. Whether does the starting foot that should measure chip of electric source control above all have the voltage that start, if do not have the voltage that start to perhaps start voltage too low, should examine the resistor that start and the cell that receive outside the foot that start whether leakage of electricity, it is normal to dominate chip like power source right now, can check breakdown quickly via afore-mentioned examinations. If have the voltage that start, the output end that measures control chip jumps in what switch on the mobile phone to whether have tall, low n for an instant change, if not have,jump change, component of oscillating circuit of bad, periphery or protective circuit have demonstrative control chip problem, can take the place of first trade control chip, if; of reexamination periphery component has jump change, be in charge of for switch commonly undesirable or attaint. 2.

Each diode and switch provide bridge of the electric capacity of great strain wave that insurance is burned or scamper basically examines 300V to go up, commutate wait for place, anti-noise circuit gives a problem to also can bring about insurance to burn, nigrescent. Those who need an attention is: Because switch canal puncture brings about insurance,burn general meeting to detect electric current resistor and chip of electric source control are burned-out. Thermal resistor of negative temperature coefficient is mixed very easily also insurance is burned out together. 3.

Have output voltage, but output voltage is exorbitant this kind of breakdown comes from commonly dominate circuit at stabilized voltage sampling and stabilized voltage. The operating ring road that in dc amplifier of sampling of resistor of output, sampling, error is like TL431, smooth Ou, power source to control the circuit such as chip to form to close jointly, any one place gives a problem to be able to bring about output voltage to lift. 4.

Output voltage is too low can cause output report depress except circuit of stabilized voltage control, still have below a few reasons also can cause output report depress: A.

Load of switch power source has short circuit trouble (especially DC/DC transformer short circuit or performance are bad etc) , right now, should disconnect all load of circuit of switch power source, it is circuit of switch power source or laden circuit have trouble in order to distinguish. It is normal that if disconnect,laden circuit voltage is outputted, the specification is laden and overweight; or still explain circuit of switch power source has trouble out of order. B.

Output voltage carries invalidation of capacitance of wave of rectification diode, filter to wait, can change a law to undertake judging through era. C.

The property that switch manages drops, bring about switch canal to cannot guide normally necessarily, make the internal resistance of power source increases, take laden ability to drop. CNC Milling