Measurement techniques for five multimeter application skills

 Now most common triode is powder coating,how to accurately judge the triode three pin which is b,c,e? Triode b very easily measured,but how to judge which is c which is e? Here recommends three methods: the first method: for measuring triode hFE jack pointer table,first measure b pole,throw triode plug into motor vehicle spare parts the socket (b,of course,is very can plug accurate),measure hFE value,then the measuring tube upside down again,the measured values of hFE larger one,each pin insertion position is correct.The second method: to measure without hFE jack table,or is not convenient to insert the socket pipe is too big,can use this method: of NPN transistors,first measure b (the pipe is NPN and PNP b and its feet are easy to measure,isn't it?) ,put table in R x 1 k Ω gear,to connect the red pens and hypothetical e very (note that take the hand don't run into table of red pens and pen or pin),the fan motor black pens and answer the hypothetical c,at the same time hold the table with his fingers tip and the pin,will pick up the pipe,with the tip of your tongue lick a b,the header pointer should have a certain amount of deflection,if all the pens and you answer correctly,the pointer will be bigger,if wrong,the pointer will be smaller,the difference is obvious.

Which can determine pipe c and e.For PNP transistors to black pens and answer the hypothetical e very (hand don't touch the tip or pin),red pens and answer the hypothetical c,at the same time hold the table with his fingers tip and the pin,and then use the tip of the tongue lick a b,if the pens and correctly,header pointer will deflection is larger.Of course when measuring the pens and to discuss the test twice,comparative reading before final decision.This method applies to all appearance triode,convenient and practical.According to the clock deflection amplitude,but also can estimate the pipe amplification ability,of course it is by experience.The third method: first to determine the pipe after the NPN and PNP type a and b,put table at R x 10 k Ω,of NPN transistors,the black pens and connect e,red pens and pick up c extremely,the clock may have some deflection,the PNP transistors,electricalmotor1.blogspot.com black pens and c extremely,red pens and pick up e very,whose hands may have a certain amount of deflection,which in turn would have deflection.This can also determine triode c and e.But for the high pressure pipe,this method is not applicable.

No load loss

 No-load loss is also called the no-load current,is refers permanent magnet motor to the vehicle power supply in the case of no load,consumes the minimum current,no-load current of the on-board power supply generally less than 0.5 amps.This parameter describes motor run capacitor the car power without succeed when used for electrical energy consumption of the size,this value electricalmotor1.blogspot.com as small as possible.To be sure,when the electrical appliances,400v ac motor car power connection to use electrical power and the consumption of electrical energy may be much larger than no-load loss,at this point the car power energy consumption depends on the car power conversion efficiency.

To identify U V W three-phase power often use colors to distinguish,U V W three-phase color,why?

Our country is:B for yellow,yellow,green and red A phase B phase for the green,phase C to red,neutral line (i.e.,zero) for light blue,protect the neutral line (ground) as the yellow and green double color Three-phase power supply how fork receiver method how to distinguish between ABC three brake rotor phase and ground wire? Phase color logo is:A phase for yellow;B phase for the electric motors 12 volt green;C phase in red.Or directly indicate the ABC phase.Ground zero line is blue,for double color line under normal circumstances,the plug or the wholesalemotor.blogspot.com socket

four conductive body,there is a show 90 degrees with other electrical conductor (sheet),whether it is a flake single phase asynchronous motor or columnar,the grounding end is longer than the other three,coarse.

The failure phenomenon:motor temperature rise too high or smoke

Reason and solutions:1.Under the heavy load or frequent starting,lighten the load,reduce the starting times 2.During operation phase - wholesalemotor.blogspot.com check the line,recovery phase 3.Stator winding connection errors - check and correct them 4.Stator winding grounding,turn or interphase short circuit - detect grounding or acmotortrading.blogspot.com short circuit,to repair them 5.Cage rotor winding -- change the rotor broken bar 6.Wound rotor winding short phase operation,find out the fault point,to repair them 7.Brush - check the bearing single phase induction motor of the stator and rotor,rotor deformation,whether for repair or replacement 8.Poor ventilation,check whether the small electric fan motor wind pass unimpeded 9.Voltage is too high or too low,check the reason and ruled out.