Transistors

I just found a problem with the brand of transistors that have been shipped to me by the vendor. I have been using PN2222A transistors that work interchangeably in the circuit. Then my vendor apparently ran out of the transistors by the manufacturer that made the transistors I had been using. Fairchild is a large company that makes a lot of different semiconductors including the PN2222A. The latest supply of transistors is made by On Semi. This company makes a transistor that is different in construction such that they "leak" in our circuit. Most people use the transistor in a linear circuit that means that they use them in an analogue mode and they can "leak" when they are biased off but still amplify a signal OK. We have a need for the transistor to switch "off" and not pass current when biased off. I have to test a sample of the batch to find out that it is apparently a flaw in design of the transistor by On Semi.

Of course, the vendor does not agree that the transistors are defective. They argue that the transistors amplify just fine and it must be a design flaw on our part. They offer to accept the transistors back with my paying the shipping and also a 20% restocking fee. I ask if they have the transistor made by Fairchild and they say yes, send those back and they will credit my account and send the Fairchild transistors in replacement minus the shipping and restocking charges. Since the circuit will not work with the On Semi parts, I mail the transistors back to them and continue to argue they are defective. They tell me the Fairchild are twice the price and agree to make the switch.

Finally a package from the supplier and I anxiously open the package and find they have shipped me another 300 of the On Semi transistors and charged me for the Fairchild! I test a sample of the On Semi and find them to be just as "leaky" and call the company to straighten this out.

They could not supply the Fairchild parts so went to another major parts supplier and found that if I ordered a reel of the transistors I could get the whole batch of the transistors for less than I was paying for 300 of them from the other guys. They are perfect and I am delighted to have them although I have thousands of them now.