Substitute for 1G sm transistor

[KevinW]

I have a K1G T3 that is shorted between the base and emitter.
Can't find it on line so I'll require a substitute.
Would the bc847c be a close match?

 

[jpanhalt]

I have a K1G T3 that is shorted between the base and emitter.
Can't find it on line so I'll require a substitute.
Would the bc847c be a close match?

My cheat sheet shows the K1G is an NPN transistor #MMSTA05 for which a MMSTA55 can be substituted. Measure the package and pin spacing. It comes in SOT23 and SOT323 packages. It is rated at 60V and o.5 A,

If your package is not one of those, then that ID might be wrong, as they often can be when based only on the SMD code.

EDIT: My other source doesn't show a K1G, but for the 1G it shows a BC847C with a BC547C as a substitute. Case is a SOT416. Check your measurements.

 

[KevinW]

Thanks for looking that up jpanhalt.
My K1G is a SOT23 and the BC847C comes in that package as well.
The MMSTA05 appears to be 500mA as you said and the BC847C is 100mA.

 

[jpanhalt]

I'd check out the datasheets for both. The 2N3904 is 200 mA and the 2n2222 is 800 mA; the 2n2222 can often be substituted.

In your case, since there is some ambiguity, I would try the higher current if the operating characteristics are comparable. Do you know what it is doing in the circuit?

 

[KevinW]

Do you know what it is doing in the circuit?

It's used for switching a 24volt 833H-1A-C relay.

 

[jpanhalt]

If it is just switching, I would go with the higher current rating -- at least as a first try.

John

 

[KevinW]

Roger that.
Thanks John.