摘要:
A pulsed power supply having a filter output and a battery backup includes electronic apparatus to sense when the AC source is failing. When the pulsed supply output has the same pulses as that which would be produced by the battery, the supply switches to battery backup mode. As the AC source returns, the supply switches to AC supply mode when the AC is at a level where the pulses produced by the supply would be the same as are actually being produced by the battery backup.
摘要:
A system (e.g., a power supply) is presented which allows a user to electrically couple a common ground electrical potential of a circuit (e.g., a power supply circuit return) to, or electrically isolate the common ground electrical potential from, an earth grounded chassis, without having to open the chassis. The system may include a metal bolt and nut, wherein the nut is coupled to an electrically conductive bracket. The bracket is mounted upon a printed circuit board and electrically coupled to the common ground electrical potential. When an insulating bushing is installed in a hole in the chassis adjacent to the bracket, and a threaded shaft of the bolt extends through aligned holes in the insulating bushing, an insulating member positioned between the bracket and the chassis, and the bracket, and the threaded shaft engages the nut, the bolt holds the insulating bushing in place, and the bracket is electrically isolated from the chassis. When the insulating bushing is replaced with a conductive washer, the bolt and the conductive washer form a conductive electrical path between the bracket and the chassis. Components of the described system may be employed in systems having multiple cabinets (or complex cabinet systems) to achieve a single point of grounding. System components may also be employed to selectively isolate or couple a power supply return to a chassis ground in devices other than power supplies.
摘要:
A current sharing modular power system including, in each module, an inverter circuit and means to determine the current to a common load from the module. A difference circuit is provided to determine the difference between the module supplied current and the average of the current supplied by the other modules. The difference is then utilized to vary the pulse width of the inverter output so that the pulses are wider if the current from the module is smaller than the current supplied by the other modules and the pulses are thinner if the current from the module is larger than the average current supplied by the other modules. The system also includes a voltage sense circuit to adjust the module operation to maintain a constant voltage output.