SL100 transistor equivalent

[Uberethair]

Hi,
I'm trying to find an equivalent for the SL100 transistor but I don't understand how to do this.
below is the link to the circuit that I'm trying to build so does anyone here know what the equivalent for this component is?

https://www.circuitstoday.com/wp-content/uploads/2008/03/intruder-alarm-circuit-1.JPG

I live in Wales (United Kingdom) if that helps.

 

[yafch]

For that circuit any general purpose NPN transistor may be used.
For discussion about SL100 please see the link to the thread. https://www.electro-tech-online.com/threads/looking-for-sl100-transistor.1164/

 

[Uberethair]

Right, thanks, could you give me an example of a general purpose NPN transistor, would a BC 108 do?

 

[yafch]

OK. the circuit works on 9v supply. So with a such voltage operation BC108 can be used.

There are thousands of general purpose transistors out there. Few of them are like. 2N2222A. 2N3053. 2N2907. BC327. BC337.BC546. BC547.BC548 ..........................are low power transistors.

For higher power transistors like, 2N3055. TiP31C. TiP32C.Tip35C.Tip36C..............
For higher voltage and low power MPSA12.MPSA42,MPSA92........................

And so on so on so on.

There are hundreds of thousands of transistors out there.
Only you need to do is check there datasheet for there parameters.
I have datasheets for about 1000 transistor and same number of IC,s and a lot of other components in my computer.

 

[Uberethair]

So that's sorted I can use the BC 108 instead of the SL100, thanks a lot.

 

[saleem sagar]

I find sl100 comparison npn transistor bc548b working equal to SL 100 transistor....

 

[MikeMl]

I find sl100 comparison npn transistor bc548b working equal to SL 100 transistor....

Hi Saleem,

welcome to the forum. Notice that the thread you replied to is 6 years old, so likely that the original Thread Starter (TS) got his question answered then, and may not be listening anymore..., especially that the TS has only posted three times...

 

[spec]

Just a few points for the record. The SL100 is an obsolete low power, high conductance transistor, rather than a small signal, high hFE (current gain) low noise transistor. The SL100 is also in a metal can, so probably has a lower thermal resistance junction/ambient than plastic case types.

The SL100 important parameters are:
VCEo max = 50V
IC max = 500mA
Pd max: 800mW
VCE sat max @150mA: 600mV
J temp max: 200 deg C (probably a misprint and should be DegCW)
thr J/amb: not stated
https://www.engineersgarage.com/sites/default/files/SL100_0.pdf

The PN2222A parameters are:
VCEo max = 40V (worse)
IC max = 1A (much better)
Pd max: 625mW (worse)
VCE sat max @150mA: 300mV (much better)
J temp max: 150 Deg C
thr J/amb: 200 Deg CW
https://www.fairchildsemi.com/datasheets/PN/PN2222A.pdf

The BC337 parameters are:
VCEo max = 45V (worse)
IC max = 800mA (better)
Pd max: 625mW (worse
VCE sat max @500mA: 700mV (much better)
J temp max: 150 Deg C
thr J/amb: 200 Deg CW
https://www.onsemi.com/pub_link/Collateral/BC337-D.PDF

As the impedance of the buzzer is unknown it is not possible to say whether a lesser transitor will be OK. But the slightly lesser VCEo of the PN2222 and BC337 will not be a problem for this application.

Metal can transistors normally have a lower thr J/ amb, so the PN2222 and BC337 possibly have a higher thermal resistance but this should not be a problem, in practice. The much lower VCE sat will more than compensate for this anyway. This also applies to an extent to PD.

The BC10x family of transistors have a maximum current of only 100mA and are not recommended. The BC54x are modern replacements for the BC10x family. The BC84x family are surface mount versions.

The 2N2907 and BC327 are PNP transistors.

End of lecture.

spec