Hello, If any of you have experience designing things for cars, your help would be appreciated. I would like to know what are the best components to use in a particular design. If you have any advice on protecting a PIC in a car, that would be helpful too. The finished unit will mount somewhere inside the passenger compartment, so temperatures should not exceed 150F or so. Parts I need help with include: P-Channel enhancement MOSFET - I'm currently using an IRF9Z34. IRF has a ton of fancy N-channel rugged MOSFET's specifically for automotive use, but I can't find any P-channel ones. I am using the MOSFET to drive a solenoid, so back EMF and negative transients are a concern. My understanding is that most modern MOSFETs have built in Zener clamps. Is this not enough? Does anyone here use Tranzorb diodes? Switching voltage regulator, 5.0V - I'm using a LM2931T-5.0. Supposedly this chip is specifically for automotive use and protects against load-dumps, reverse polarity, etc. BJT Transistors: I hoped a 2N2222A would work fine. Any reason it won't? I shouldn't need to drive more than 250mA or so through the collector. PIC - a 16F84A. Forgive me if these questions are simple, but I am no EE! Thanks, -Anuj Varshney anuj@varshney.net -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.