Grid-connected photovoltaic power system Solar energy gathered by photovoltaic solar panels, intended for delivery to a power grid, must be conditioned, or processed for use, by a grid-connected inverter. Fundamentally, an inverter changes the DC input voltage from the PV to AC voltage for the grid. This inverter sits between the solar array and the grid, draws energy from each, and may be a large stand-alone unit or may be a collection of small inverters, each physically attached to individual solar panels. See AC Module. The inverter must monitor grid voltage, waveform, and frequency. One reason for monitoring is if the grid is dead
Nuclear Instrumentation Module for logic signals. The fast logic standard (commonly known as NIM logic) is a current-based logic, with negative true (at −16 mA into 50 ohms = −0.8 volts); an ECL-based logic is also specified. Apart from the above mentioned mechanical/physical and electrical specifications/restrictions, the individual is free to design their module in any way desired, thus allowing for new developments and improvements for efficiency or looks/aesthetics. NIM modules cannot communicate with each other through the crate backplane; this is a feature of later standards such as CAMAC and VMEbus. As a consequence, NIM-based ADC modules are nowadays uncommon in nuclear