Counterfeit Semiconductors

[E-design]

"So, off you go to the local parts shop to buy some transistors (or indeed, other parts!). Having decided the devices that fit your needs (having selected any of a number of devices that are suitably rugged and powerful), you hand over a not insubstantial amount of cash and head home to build the masterpiece. Inexplicably, the expensive output transistors fail, but you know that their ratings are well within the design limits for the project you are building. This happens once, maybe twice, or perhaps more. You get discouraged, and shelve the project -having already spent quite a lot on all the parts needed."

**broken link removed**

 

[Mr.Cool]

unbelievably, this happened to me. i had to scrap the whole lot of parts. now i buy only from manufacturer or reps.

Mr.Cool

 

[fala]

In one sensitive project I used Op07 for its very low voltage offset but I noticed that offset of this Opamp can change in matter of some mv! depending on relatively minor changes of environment temprature.

 

[dipal_z]

I have faced this problem with power transistors available in TO-3 package. If you open the metal can of this package you can find the some small transistor in TO-37 package will be mounted inside. As this little fellow can't handle that much current your output stage will burn mostly in first power cycle itself.
Buy these things only from trusted sources.