diagram circuit

This non transistor tester circuit devices that isn’t accurate, but utility of this test device enough assisting in assaying of quality of transistor. This circuit can show promise about condition of a transistor is still in condition either or have been in condition of breakdown. Besides, earns also applied to test amplification of current from the transistor is categorizing transistor type A (amplifier of current 140 - 270), transistor type B (270 - 500), or transistor type C (amplification > 500).

For example earns we to take a n p-n transistor as transistor which will be tested. The transistor packed into socket appropriate TUT = Transistor Under Test) hereinafter switches S2 is attached according to at schematic. If LED D2 blazed, hence the transistor is type C, medium if LED didnt ON, switches S2 must be removed on course middle and if still had not blazed, removes switches to last position. If LED is ON at course last switches, means transistor is type A.

On the contrary, if LED remaining to extinguish though had been tested at all of position of switches, hence transistor had been in condition of breakdown or has amplification of current smaller than 140, so that for transistor having small signal basically cann’t be utilized. Bases current to transistor is being tested able to be broken by using switches using compress switches. If LED still in condition blazed, means happened links shortening between colector and emitor at the transistor.

This very simple circuit work principle. Transistor tested receives bases current around 10mA through R1. With assumption that transistor is still be good, the thing will yield strain at R2 until R4 and depend on position of switches S2, some of this voltage compared to to a reference voltage by utilizing IC 1. Mode of action from circuit which its inside is also approximately equal, only inside of circuit destined for PNP transistor. The supply of the voltage is required by this circuit only from battery.