Identify Transistor Configuration: Easy Tips & Tutorials

[Borg]

I've got a bunch of misc. transistors from various sources and I'm not sure what types they are. Is there an easy way to generally determine how a transistor is configured or do I have to find a data sheet each time? It's been a long time since I did anything with electronics. From what I've read, I need to know if it's PNP or NPN and what the arrangement of the collector, base and emmiter is. Any good links to transistor tutorials would be appreciated as well. Thanks.

 

[vk6kro]

Most digital multimeters have a transistor test function on them. You can use this to learn enough about a transistor to know when to use it.

If you don't already have a multimeter this is an example of what is available now:
http://www.harborfreight.com/7-function-digital-multimeter-92020.html

The little blue circle on that meter is the transistor testing socket. You insert the transistor in different positions until you get a sensible Hfe (current gain) figure on the display. This would be a number between 50 and 500, probably. Not bad for $5.

For $20 you can get better ones that measure temperature, frequency and capacitance as well as all the usual ranges.

 

[Borg]

Most digital multimeters have a transistor test function on them. You can use this to learn enough about a transistor to know when to use it.

If you don't already have a multimeter this is an example of what is available now:
http://www.harborfreight.com/7-function-digital-multimeter-92020.html

The little blue circle on that meter is the transistor testing socket. You insert the transistor in different positions until you get a sensible Hfe (current gain) figure on the display. This would be a number between 50 and 500, probably. Not bad for $5.

For $20 you can get better ones that measure temperature, frequency and capacitance as well as all the usual ranges.

Thanks, vk6kro. It has been a very long time since I worked with electronics. I had no idea that meters had those capabilities. Now that I know what to look for, I found a site with lots of multimeters that looks pretty good (http://www.multimeterwarehouse.com" ). It looks like they have a good assortment of multimeters including transistors, capacitance and even inductance for a reasonable price.

 

[vk6kro]

Good. You need a multimeter or even several multimeters.

Chances are you won't get to use those transistors, but a good multimeter won't go to waste.

If I could raise a personal preference, don't get an "Auto-Range" meter. These can drive you nuts. They can change from measuring microamps to milliamps without you realising it and give crazy effects.

There are meters that have clip-on leads for checking components. These are better if you have a lot of transistors to check.