This article reports the design and its special features for various g
rid biases for a retarding potential analyzer instrument aboard Indian
satellite SROSS-C2 to ensure trouble free functioning of electron and
ion traps. The polarities of the various grid biases, identify the di
fference between ion traps and electron traps. A new concept of genera
ting bias sweeps on line for future missions has been proposed. (C) 19
97 American Institute of Physics. [S0034-6748(97)02211-9].