Can a BC237B substitute a BC548?

Thread Starter

spikespiegelbebop

Joined Nov 30, 2021
30
I'm pretty bad at analyzing equivalent transistors and recently I bought some at a local store, but only today I realized that the ones they gave me don't seem to be equivalent, so I need to know if a BC237B can substitute a BC548.
 

Ian0

Joined Aug 7, 2020
5,163
As all bipolar transistors work the same way, any transistor can, within reason, be substituted for any other transistor of the same polarity.
Just check the following:
Is the voltage rating Vceo high enough?
Can it take the power?
Does it have enough gain? (Hfe)
Does it have enough frequency response? (Ft)
and, perhaps,
are the pins in the same place?

They don’t have to match precisely, just to be higher or the same.

if you understand the circuit into which you are substituting the transistor, you can check not whether the new transistor matches the old, but whether the new transistor will work in the circuit.

very occasionally you will encounter a poorly-designed circuit where the operation depends on the transistor having a low Hfe, and your substitution might not work.
 

Alec_t

Joined Sep 17, 2013
12,818
The two transistors are both NPN silicon and they have the same pinout and packaging. Unless they are in a critical circuit section they are probably near enough matched.
 

Thread Starter

spikespiegelbebop

Joined Nov 30, 2021
30
It's for this circuit.

Datasheets:
BC237B
BC548

Also, I wonder: can anyone tell me if there's anything wrong with the circuit by just looking at what's written and shown? I had someone criticizing the IC used, but I don't thing there's anything wrong at all.
 

bertus

Joined Apr 5, 2008
21,899
Hello,

In the old days ELEKTOR used "universal" transistors and diodes.
They called the TUN TUP DUS and DUG:
tun tup dus dug.jpg
Bertus
 

Thread Starter

spikespiegelbebop

Joined Nov 30, 2021
30
@ericgibbs I was told that the vertical and horizontal syncs are not required if I'm going to use the amplifier on the tv's neckboard, meaning that the lm1881 and the 74l221 will be discarded, thus being a waste of time and resources if I use them.
 
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