IDENTIFY Transistor from its Hfe Value

[BHARGAVSHANKHALPARA]

Hello all..!!

i am working on one project. in that i want to use transistors as switching mechanism. actually i am building this circuit based on one old circuit.

in old circuit i find two transistor in T0-220 package.Transistor name are not seen.

i have PEAK SEMICONDUCTOR COMPONENT ANALYZER, it can also detect leads of transistor automatic.



i connect my old circuit transistor to it one by one. and i got following data for each transistor

TRANSISTOR ONE DATA :

1 ) Device Type : NPN SILICON TRANSISTOR
2) Test Current Ic = 2.50mA
3) Base Emitter Voltage Vbe =0.67V
4) Test Current Ib = 4.62mA
5) Leakage Current Ic = 0.00mA.
6) Hfe = 76

TRANSISTOR TWO DATA:

1 ) Device Type : NPN SILICON TRANSISTOR
2) Test Current Ic = 2.50mA
3) Base Emitter Voltage Vbe =0.67V
4) Test Current Ib = 4.62mA
5) Leakage Current Ic = 0.00mA.
6) Hfe = 78

My problem is that...after getting this data i have i search many datasheet of transistor, there is no any matching of this Hfe.

How i can find perfect transistor..?

is above parameters are enough..?

please suggest what to do..?

 

[Audioguru]

A transistor in a TO-220 case is usually used at 1A to 3A, not at just 0.0025A like your tester uses.
hFE is not used when the transistor is a saturated switch anyway, usually the base current is 1/10th the collector current for a switching transistor but at higher currents the base current might need to be 1/3rd the collector current.
hFE is used when a transistor is a linear amplifier that always has plenty of collector to emitter voltage so it is not saturated.

Transistors have a maximum voltage rating and a maximum current rating. Your tester does not tell you these very important specs.