Abstract: A system for connecting an ignition device to a direct current network wherein the ignition device is capable of being activated for triggering a safety device in an emergency. For example, the safety device can be constituted of a safety belt tensioner or an airbag in a vehicle arranged to be inflated by a gas generator upon detection of a certain deceleration of the vehicle. At least one safety device is connected to an internal network of the vehicle via an electronic unit including at least one acceleration sensor and an arrangement for the generation of a direct current voltage for activating the ignition device at a given deceleration, the direct current voltage generated being higher than the internal line voltage. The system is dimensioned such that the direct current network of the vehicle does not have a potential that is high enough to activate the ignition device.