Abstract: A fire fighting simulator includes a projector to project an image of a fire on a screen and a shutter assembly to occlude portions of the image. The extinguishing agent is simulated by an infrared beam and the shutter assembly is controlled to occlude portions at locations impinged by the beam. The control also polls each element of the shutter assembly periodically and opens the elements selectively to simulate reflash of the fire.

Abstract: An electronic battery charger for charging various types of dry cells including nickel-cadmium batteries provides for a cool down phase during battery charging cycle once a maximum predetermined temperature or voltage for the battery has been sensed. Subsequent to the cool down phase, a charging current is controlled in a manner such that, as battery temperature continues to decrease, a control device increases the charging current applied to the battery. Once a reheating of the battery is detected, the control device decreases the charging current. In this manner, a maximum charge is achieved in the battery at a temperature close to the ambient temperature.

Abstract: A lamp rechargeable dry cell power pack and recharging device therefor is disclosed. The recharging device comprises a socket for receiving the power pack, a plurality of electrodes are presented in the socket and arranged to contact corresponding electrodes on the power pack when it is fully inserted in the socket. The power pack is irregular shaped in cross-section and the socket is correspondingly shaped to receive and support the power pack in only one orientation of the power pack relative to the socket to ensure the registration of the plurality of socket electrodes with corresponding power pack electrodes.