power assisted NiCads

14 power-assisted NICADs In many instances where NICAD batteries are used to power immobile equipment it becomes necessary at times to remove the cells for a "topping up" session. This can of course lead to a certain amount of inconvenience, especially if there is no spare set of NICADs available for replacement. Also, it is not uncommon for NICADs to be used as a "battery back-up" for mains powered equipment, in which when case the NICADs are only used very sent, the mains actually fails. There are, however, a number of applications (such as clocks, alarm systems etc.) where the NICAD cells can be used to power the equipment together with a small mains power supply to provide the cells with a "trickle charge". The circuitry is then not dependant on the presence of the mains supply and the NICAD cells are given a full time job. articularly useful when the This last application is p the load on the batteries can size and duration not be accurately piedicted (as in the case of alarm...