Department Defence Orb

The Department Defence Orbs were used by the Department to guard detention facilities such as Dauntless Prison. When K9 tracked a Jixen warrior to the prison, he was intercepted and disabled by the machines, but managed to repair himself shortly after (TV: Liberation)

The defence orbs were also used as stun mines, if someone got within its range, it would encase itself in a blue bubble, giving the person an electric shock. These stun mines were used in the sewer as an attempt to corral a surviving Jixen warrior. (TV: Hound of the Korven)

Behind the scenes
In Liberation, they were CGI, whereas the stun mines from Hound of the Korven were practical effects.