eeeeeeeeeeeeeeeeeeeeeeeee COMPONENTS.pptx

wene

1. TESTING ELECTRONIC COMPONENTS

2. DIODES AND TRANSISTORS when using an analog instrument to test a dide , the needle will swing almost fully across the scale when the diode is placed in one direction and hardly move when the diode is reversed

3. TRANSFORMERS AND COILS transformers are tested by measuring the resistance of the copper wire on the primary and secondary. since the primary has more turns than the secondary, and is wound using thinner wire, its resistance is higher, and its value is in range of tens of ohms (in high power transformers) to several hundreds of ohms.

4. POTENTIONMETERS TO TEST A POTENTIOMETER, (POT), OR A VARIABLE RESISTOR, THE PROCESS IS RATHER SIMPLE YOU CONNECT THE COMPONENT TO THE PROBES OF A METER SET TO OHMS

5. CAPACITORS should produce an infinite reading on a multimeter. exceptions are electrolytic and very high value block capacitors.

6. TRANSFORMERS AND COILS TRANSFORMERS ARE TESTED BY MEASURING THE RESISTANCE OF THE COPPER WIRE ON THE PRIMARY AND SECONDARY. SINCE THE PRIMARY HAS MORE TURNS THAN THE SECONDARY, AND IS WOULD USING THINNER WIRE, ITS RESISTANCE IS HIGHER, AND ITS VALUE IS IN RANGE OF TEN OHMS (IN HIGH POWER TRANSFORMERS) TO SEVERAL HUNDREDS OF OHMS.

7. SPEAKERS AND HEADPHONES when testing speakers, their voice-coil can be between 1.5 and 32 ohms. the value marked on the speaker is an impedance value and actual dc resistance will be lower

8. CONDUCTIVITY PROBE is a simple, but very important instrument, which is able test for faults many components like: diodes, transistors, coils, transformers, speakers and headphones, capacitors, switches, jumpers, cables and may other different electronic components. this method is a lot faster and straightforward that it is using some “ offvthe shelf” instrument .

9. SEMICONDUCTORS CHECK to test diodes using this circuit, we fall back to the diode theory of operation, when anode is positive comparing to the cathode (red probe on anode, black on cathode), whole diode acts as a low value resistor, which means that speaker sound is higher than usual.

10. TRANSISTORS WERE CONSIDERED THE INVENTION OF THE TWENTIETH CENTUARY THAT CHANGE ELECTRONIC CIRCUITS FOREVER .

11. PASSIVE COMPONENENTS COMPONENTS INCAPABLE OF CONTROLLING CURRENT BY MEANS OF ANOTHER ELECTRICAL SIGNAL ARE CALLED PASSIVE DEVICES. RESISTORS, CAPACITORS, INDUCTORS, TRANSFORMERS AND EVEN DIODES ARE ALL CONSIDERED PASSIVE DEVICES.