Dc voltage measurement

This is a current situation,the multimeter dc voltage in the dc power supply voltage,measure the working voltage of peripheral components;Different IC pins of dc voltage value,and compared with the normal,and compression failure,find out the damaged components.When measured at 8 o 'clock to pay attention to the following:(1) the multimeter to want to have enough resistance,at least more than 10 times greater than the resistance of the circuit being measured,so as not to cause greater error of measurement.(2) usually put the potentiometer to the middle position,if it is a TV set,signal source to adopt standard color bar signal generator.(3) to take pens and asynchronous motor or probe anti-skid measures.For any instantaneous short circuit is easy to damage the IC.Can take the following methods to prevent the pens and sliding: take a bike with a valve core set of pen in the table,and the long table pen is about 0.5 mm or so,it can make the table pen well and the point contact under test,and motor run capacitor can effectively prevent the skid,and even meet with neighboring points can not short circuit.


(4) when the measured voltage does not accord with normal,a pin voltage should be based on the pin to IC normal work have important influence as well as the other pin voltage were analyzed,and the corresponding change to ac electric motor judge of IC.(5) IC pin voltage will be affected by peripheral components.As peripheral components occurs leakage,short circuit,open circuit or value,or peripheral circuit connection is a variable resistance value of the potentiometer,the location of the potentiometer arm,will make the change pin voltage.(6) if IC voltage is normal,the pin is thought IC is normal;If abnormal voltage IC part pin,it should maximize deviation from normal,check the peripheral components for XXX,if wholesalemotor.blogspot.com no failure,the IC is likely to be damaged.(7) for dynamic receivers,such as TV,in the presence of signal,IC pin voltage is different.If discover pin voltage should not change but change is big,the size and adjustable with the signal components of different locations and change but do not change,can determine the damage of the IC.(8) for a variety of ways of working device,such as video,work in a different way,each pin voltage IC are also different.