A drive arrangement (1) for driving a vehicle safety device (18) incorporates an input (2) which is connected to an output (9) of an electronic control unit (5). The output (9) of the electronic control unit (5) is an output which is operable to provide a firing signal to activate a pyrotechnic squib in a safety device, such as an airbag module. The drive arrangement (1) incorporates first and second analyzers (14, 15) which perform first and second algorithms on a firing signal provided by the electronic control unit (5) to determine that the firing signal would have activated a pyrotechnic squib. The drive arrangement (1) provides an output signal to a safety device (18) if both the first and second analyzers (14, 15) determine that the firing signal would have activated the pyrotechnic squib.