A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. It is composed of semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor’s terminals changes the current flowing through another pair of terminals.
Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.
All Type Transistor Base leads view & smd type
NPN Transistor TESTING By Digital multimeter.
SELECT DIODE MODE DIGITAL MULTIMETER.
- Connect DMM (+) Test Red lead to Base
- ………….DMM ( -) Test Black lead to Collector =display shows the reading = 0.615v
- ………….DMM (-) Test Black lead to Emitter = 0.645v
- Connect DMM (-) Test lead to BASE
- ………….DMM (+)Test lead to Collector reading shows = OL or ‘1’ or OPEN
- ………….DMM (+)Test lead to Emitter = OL or ‘1’ or open.
- DMM (+) Test lead to collector
- DMM (-) Test lead to Emitter.
- DMM (-) Test lead to collector
- DMM (+) Test lead to Emitter
DMM Reading shows = OL or ‘1’ or open (overload) the condition is GOOD.
Verification: If you get reading in forward bias as 0000 or ‘OL’ or ‘1’ or open and in reverse bias as 0000 (or) low values the transistor can be FAULTY and needs replacement.
DMM (-) Test Black lead to Collector reading shows = 0.449v
DMM (-) Test Lead to Emitter = 0.502v
Verification: If the DMM reading is from 0.502v to 0.449v the condition is GOOD.
Connect DMM (-) Test lead to BASE
DMM (+ )Test lead to Collector reading is = OL or 1 or open
DMM (+ )Test lead to Emitter = OL or 1 or open
DMM Reading shows = OL (over load) the condition is GOOD
TEST YOUR TRANSISTOR BY BELOW CIRCUIT (SL-100 TYPE)
Required components are: R1k,Rl-470E, Tr SL-100, Toggle switch-1., Connect a LED in series with collector RL (load resistor) the LED.
When the switch is open the LED condition is OFF.
Close switch sw1 to base now LED condition is ON.
Please let me know the DIMM reading of a good, bad and weak 2N3055 transistor and the best process of testing that kind of transistors. Thank you.
I tested transistor 2SC1971 with the above steps, step 1,2,3 shows good, but on step 4 I got reading of 0.623 ! does that mean transistor is faulty? its new RF amplifier and I used Auto ranging digital mustimeters set at Diode test.