other known arrangements may be used for the malfunction detector 11 in such a case the malfunction detector 11 only needs to be able to detect a discontinuity in the ignition squib 7 it is not necessary to include a check of the operational status of the driving circuits if the malfunction detector 11 determines that there is no malfunction in the ignition system of the ignition squib 7 the malfunction detection output signal ts goes high whereby the selection switch 8 assumes the state indicated in fig1 by a solid line and the second discrimination output c2 is input to the second driving circuit 9 if however the malfunction detector 11 determines that there is a malfunction in the ignition system of the ignition squib 7 the malfunction detection output signal ts goes low whereby the selection switch 8 assumes the state indicated in fig1 by a broken line and the first discrimination output c1 is input to the second driving circuit 9 as well as to the first driving circuit 6 thus providing there is no malfunction of the ignition system of the preloader device x that is set to be triggered first the first discrimination output c1 is input to the first driving circuit 6 and the second discrimination output c2 is input to the second driving circuit 9 so that in a.