Virtually all Nikon SLRs are protected against high trigger voltage up to 250V or so, but sometimes when using a dedicated flash, extra pins will interfere with the operation. I actually have a 3rd party old dedicated flash for Nikon that won't fire on a newer Nikon camera because the 3rd party flash ready signal doesn't match what the camera is expecting. You can insure that side effects don't happen by using a piece of electrical tape to insulate all but the center pin of the flash, or by mounting the flash to a cold shoe and firing it with a PC cord.