Electromagnetic pulse

An electromagnetic pulse (also known as EMP) is a discharge of electromagnetic radiation emitted by certain devices that can render the technology of certain races inert, albeit temporarily.

Uses
In Pete's World, the Preachers possessed EMP bombs that were used to destroy computers. Using one on a Cyberman had the effect of crippling it and disabling it's emotional inhibitor.

Since Bannakaffalatta was a Cyborg, he had an EMP device, which was capable of knocking out Heavenly Hosts (stops them flying, and starts falling). However, they were only stunned temporarily. Also, since they use up too much power, Bannakaffalatta had little power left and died. However, Bayldon Copper, Astrid Peth and Rickston Slade were able to obtain the EMP device that is rechargable and used it to knock out other Hosts. (DW: Voyage of the Damned)