High efficiency solar cell array peak power tracker and battery charger

The unit described here is designed for the Airlock Vehicle that will permit coupling between an Apollo spacecraft and a Saturn IVB stage to form a manned orbiting workshop. Solar cell array power, converted by a switching regulator, is used to charge a battery and supply spacecraft loads. Maximum power is extracted from the array if the combined battery and load power requirements exceed the available array power. In addition, the charger provides trickle charge, charge cutoff, and battery voltage and temperature limit functions while supplying spacecraft load power. The special feature of this unit is that the peak array power can vary from 7 0 watts to 2580 watts. Operating array open circuit voltage can be as high as 125 volts. Another feature is that failure of any component will, at most, result only in a slight performance degradation.