loudspeaker fuse

7-78 elektor july/august 1980 85 Loudspeakers, like rules, are designed to be broken. Perhaps not entirely true but they do suffer an enormous amount of punishment especially at Rock concerts and festivals. Even if the rated power indicated on the loudspeaker cabinet is not exceeded, high frequency systems may die of heat, because DIN standard measure- ments do not correspond with the hearing habits of Rock fans. High sound levels, part and parcel of any form of Pop, can easily cause speakers to come to a bad end during continuous duty on "full power". It is also fairly obvious that high volt- age levels across the amplifier output will cause low frequency speakers to expire with an unwanted smoke effect. Often the fuses available inside the amplifier aren"t activated until the post mortem. This article describes a novel circuit which will disconnect the loudspeaker systems before volt- age levels reach the stage where damage to the speakers could occur. The circuit will protect c...