Bus voltage control using gated fixed energy pulses

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG.
1A, a functional block diagram is illustrated of a power bus controller or regulator in accordance with one embodiment of the invention.
The bus shown at 10 has capacitors 12 which are charged to a desired voltage level for energizing a load 14.
Load 14 can be electronic circuitry in a communications satellite, for example, which can vary from no load to a light load or a heavy load.
Particularly in a satellite application, a power source such as solar cells (not shown) can be continuously connected to power bus 10 as a power supply.
In addition, or alternatively, a battery 16 provides power to bus 10 as needed.
In this embodiment, the voltage on bus 10 is to be maintained between an upper voltage of 70.
1 volts and a lower voltage of 69.
7 volts.
The lower voltage is maintained by a boost circuit 18 which includes a comparator for comparing voltage on bus 10 with a reference voltage (69.
7 volts) and which controls a switch 20 for applying fixed energy pulses from battery 16 to bus 10 through diode 22 and RF choke 24 when the voltage on bus 10 drops to or below 69.
7 volts.
Additionally, in this embodiment a shunt circuit 26 compares bus voltage to a reference voltage (70.
1 volts) and controls switch 28 when bus voltage exceeds the reference voltage.
The gated fixed energy control allows energy pulses to be connected through a resistive coil 30 and diode 32 and switch 28 to a circuit ground to remove excess voltage.
In an alternative embodiment illustrated in FIG.
6A, excess voltage on bus 10 is used to recharge battery 16 rather than the dissipation of excess energy to ground.
Other elements of FIG.
6A are similar to the elements of FIG.
1A and have the same reference numerals.
Operation of comparators 18, 26 and the gated fixed energy control through switches 20, 28 is simple in implementation since the mechanism functions as a state machine in monitoring the voltage on bus 10.
No complex feedback circuitry is required and there is no control of the duty cycle of each pulse as the pulses have a fixed energy content in watt-seconds