Hi all, I must point out that I am quite new to electronic design. I have designed my first circuit with the help of a friend (who is now overseas), and I am having some issues. It is a very small circuit for a micro controller to drive a relay for turning on/off an a fan in my computer room. The circuit works, but the transistors keeps burning out on the board. Once I replace it, it is ok for a short while then dies again. I am not sure if I got a dodgy batch of transistors or there is a problem with my circuit... If there is a problem in the circuit I am thinking it may be with the placement of D1, or R1 is not big enough but in reality, I am stumped! I have attached a small design i sketched up in paint, i am still learning my way around LTspliceIV and this is all I could whip up in the short term. I should also point out the ground is common between the 5v and 12v sources! Any help you can offer would be greatly appreciated. I will be only too happy to answer any questions you may have if additional info is required!