CCTV camera power supplies come in 12 volt DC or 24 volt AC. Most cameras run on 12 volt DC, however, there are a few CCTV cameras that run on 24 volt AC. When selecting a CCTV power supply, care must be taken to choose the correct type. Multi-port CCTV power supplies allow you to easily manage power to all of your cameras at a central point. This makes installation simple and neat. A single port power supply is a good choice for 1 to 2 camera installations. A power supply is usually installed near your DVR.