Q954 unable to find data sheet

[Cag]

Repairing a board off an old dremel tool and can’t identify one of the components. It’s marked with Q954 and A2. looks to me like a triac or a mosfet but I have no idea. Couldn’t find any data sheet for it.

 

[kellys_eye]

That looks like an old 'lockfit' type of transistor - inevitably an NPN but of standard enough parameters that practically any NPN (like the ubiquitous BC548) would work in its place. However if that's a 'mini heatsink' type thingy poking out the back of it then use a suppliers parametric search engine to look for a small transistor NPN capable of handling up to 3A.

I seriously doubt you'll find another lockfit device anywhere except via a old 'ham' radio enthusiasts junk box.

All you need to be aware of are the pinouts as they differ between packages.

YMMV.

 

[Bluejets]

If it's a speed control, more likely it's a triac or thyristor.

 

[kellys_eye]

Good spot - suggest something like a C106 to replace it.

 

[Cag]

If it's a speed control, more likely it's a triac or thyristor.

yes it is a speed control, any part numbers you would reccomend for that component?

 

[bertus]

Hello,

Perhaps there is some info in the following thread on eev:

help me pick a triac to fix my old Dremel - Page 1

help me pick a triac to fix my old Dremel - Page 1

www.eevblog.com

Bertus

 

[Cag]

Just had one more question. There is an unmarked capacitor that connects to the gate of the Triac, it reads 0.32 Nanofarads but I'm not sure how to check if it's good or not. I suppose I could do a voltage test but I don't know what it's rated for so I don't want to overcharge it.

 

[Bluejets]

No, not a capacitor.
More likely a diac.

 

[kellys_eye]

That device will be a DIAC.

 

[Harald Kapp]

See e.g. here how a DIAC is used in a thyristor control circuit.