Source: Unearthed Arcana 7 - Modern Magic

5th-level transmutation (technomagic)

Casting Time: 1 action
Range: 120 feet
Components: V, S
Duration: Concentration, up to 1 minute

This spell shuts down all electronic devices within range that are not wielded by or under the direct control of a creature. If an electronic device within range is used by a creature, that creature must succeed on a Constitution saving throw to prevent the device from being shut down. While the spell remains active, no electronic device within range can be started or restarted.

Spell Lists. Sorcerer, Warlock, Wizard