When fire breaks out in a building, lives are at risk. Particularly in high-rise office blocks, it is vital that fire alarm systems are 100 percent reliable, even in the event of a power failure. Karen Lontka has invented a special electrical circuit which ensures that the voltage available to a fire alarm system is always adequate — even in the event of a blackout, when the alarm system is powered by a battery. Lontka works in the Infrastructure & Cities Sector in Florham, New Jersey, U.S. Her new circuit is already in use in the fire alarm systems produced by Siemens in the U.S.