The Q2 is an NPN transistor and the constant current flows into the collector lead. The value of constant current can be given by the equation (V D1 -0.6)/ (R2+R4).The POT R4 can be adjusted to get a constant current of 10uA. Hfe as high as 1000 can be measured by using this circuit.The circuit is based on two constant current sources build around transistors Q1 and Q2.The Q1 is a PNP transistor and the constant current flows in the emitter lead. Both PNP and NPN transistors can be checked using this circuit. Here is a very simple circuit that can be used to check the hfe of transistors. (Contains both Circuit Diagram and PCB Lay Out) 3. If you have any doubts about any section please ask through comments.

We have structured this article into two circuits. This article discusses various circuits that can be used to test a Transistor, both NPN and PNP. Skema Rangkaian yang biasa juga disebut lampu cas ini sudah dicoba dan rangkaian ini mampu beroperasi selama 8 jam tergantung dari aki yang kita pakai tapi lebih efektif jika kita menggunakan aki kering tapi harganya lumayan mahal dan menggunakan relay sebagai sakelar otomatis jadi kita tidak perlu repot-repot karena rangkaian akan secara otomatis menyala bila lampu padam dan dan bila listrik menyala maka rangkaian ini akan otomatis melakukan pengisian dan rangkaian ini sangat cocok untuk tugas-tugas sekolah jika masih kurang jelas silakan komentar yah.

Buku persamaan ic dan transistor tester