What is description of bc147 transistor?

Answer 1

This is the European "Pro-electron" numbering system compared with the US JEDEC system (2N etc)

First - Letter

A = Germanium Device
B = Silicon Device
C = Gallium Arsenide

Second - Letter for A/B/C devices

A = small signal diode
C = small signal general purpose transistor (for audio or slow speed switching)
D = power transistor (audio and low frequency applications_
F = small signal RF transistor
T = SCR / Thyristor
U = power transistor for switching applications
Y = rectifier diode

Third + Fourth + Fifth - Unique identifier number

Some manufacturers put some significance on the number. For example Mullard/Philips treated the second digit of 4 meaning NPN Lockfit case and 5 meaning PNP lockfit. Many used 6 for TO92 cases.

An optional letter followed indicating a gain grouping ... typically A being lowest, B middle and C highest

Different manufacturers created similar transistors with different type markings.

e.g. BC107 BC167 all functionally very similar.

So, the BC147 is a Silicon small signal audio transistor with a "Lockfit case" originally manufactured by/for Philips/Mullard. A viable replacement today, if you can't find a 147 is a BC547 If there's a gain grouping letter, you need to match the gain grouping either by a comparable letter, or by testing. Careful with the pinout.

There are a cluster of similar transistors ...

So, the BC147 is one of a cluster of 3 similar transistors ... BC147/148/149. BC147 has ratings of VCE 50, VCB 45 ICMAX 100 hfe 125-500
BC148 has ratings of VCE 30, VCB 20 ICMAX 100 hfe 125-500
BC149 has ratings of VCE 30, VCB 20 ICMax 100 hfe 240-900 Noise 2dB

Lockfit transistor pinout (wideface down)
B
E C

BC547 pinout (flatface down)

E B C

Answer 2

BC-147 was an extremely popular NPN transistor originally released in the mid 1070s bt Philips Semiconductor for Audio applications. Its parameters are as follows: Vcbmax= 50V, Vcemax = 45V, Vedmax=6V, Icmax=200 mA, Tjmax= 125C, Ptot= 250 mWf Ftmin=150M HFE= 110mn HFE bias= 2mA. Other variations of the BC-147 are BC-147A, BC-147B, BC-148, BC-148A, BC-148B, BC-148C, BC-149, BC-149B and BC-149C with slight variations mostly in the HFE (gain) parameter. The group was referred to as the BC-147 family. All members were NPN. None of the transistors of the BC-147 are manufactured anymore. However there are many other equivalents available. Data sheets for the BC-147 family are are easily available all over the internet as well as in various electronics reference books.

Answer 3

> BC 147 CODE stands for base collector transistor where the amplifying factor is 147

Whoever wrote that made it up.

B is the junction material. In this case, Silicon.

C is the application. In this case it means low power audio frequency.

147 is just a number with no particular system.