Abstract: Provided in a portable lamp is a cathode-heatable fluorescent bulb which is supplied from a rechargeable battery. For the purpose of charging, the lamp is coupled with a charging device situated in a region which is not at risk. The charging device is provided with separate connections for the charging voltage and for the application of a heating and starting voltage. At the beginning of the recharging phase, the battery current supply circuit for the bulb is interrupted. When removing the lamp the battery current supply circuit is closed, a heating voltage made available from the charging device and applied to the cathode of the bulb. Thereafter, the starting voltage is developed in a starting device and applied to the bulb electrodes. Only after striking of the bulb is the lamp electrically decoupled from the charging device. Starting with preheating is thus effected by means of the charging device. The lamp includes an incandescent bulb with a separate reflector.

Abstract: The personal safety radio device is carried by the person to be protected on a mounting device, for instance incorporated in the heel of a work shoe, and includes a transmitter powered by a current source specific to the device, a receiver and an antenna arrangement. In order to ensure a high operational reliability and a long maintenance-free service life at a high range of transmission the device- specific current source is a rechargeable accumulator which may be charged by a generator arrangement including a piezo-electric converter during the operational useage of the device. The piezo-electric converter is so arranged in the work shoe that it is acted on by the weight of the person wearing the work shoe and thus converts the pressure of the weight into electrical energy.

Abstract: A staff-location and signal system for mines, in which conventional radio telephone devices can be used for producing a radio telephone connection between an exchange and base stations or between the base stations and radio telephone equipment in the mine area. All underground employees, whether they carry radio telephones or not, can be reached by warning signals or staff-location signals sent via apparatus carried by the employees. To this end, the miner's lamps are associated with radio receivers which respond to cooled signals transmitted by the base station and thereupon actuate a switching device. The normally-closed working-current circuit of the lamp contains a switch which can be operated by the actuated switching device so that it switches the miner's lamp on and off. In this manner all miners can be raised when necessary by warning or staff-location signals in the form of flashes.