DS200NATOG2A is a Voltage Feedback Scaling Board manufactured and designed by General Electric as part of the Mark V Series used in gas turbine control systems. The Voltage Feedback Scaling board (NATO) attenuates the AC and DC voltages of an SCR bridge so that bridge voltage feedbacks may be accurately derived. It works in conjunction with two other boards, a VME backplane and a gate distribution and status board.
INPUT:
The NATO board contains five identical, series-connected strings of precision resistors. There is one string for each of the three AC phases, and one more apiece for positive and negative DC bus voltage. Each string can be configured using a selection of three different input stab connectors and two wire jumpers to at-tenuate 6900. 4200. 3300, 2200, or 1200 volt input.
OUTPUT:
The outputs of the five strings are connected to a single 20-pin ribbon header (see Table 2). A metal oxide varistor (MOV) prevents the output voltage of each string from becoming too high if the output ribbon circuit is interrupted while the input voltage is present. The burden resistor is located on the gate distribution and status board, rather than the NATO board.
APPLICATION DATA:
RESISTOR STRINGS: The resistors on this board are grouped into five resistor strings denoted by the letters A through E (see string headings in Figure 1). Each string has three input points (stab connectors) for a total of 15 input points. Each string also has two optional wire jumpers, for a total of 10.
STAB CONNECTORS: Three stab connectors in each of the five resistor strings allow the user to connect input power to a varying number of the resistors, in order to accommodate a range of voltages. In the Stab Connector column of Table 1, replace x with the designator of the string to ascertain the appropriate connector. For example, for string C, the relevant stab connectors are JC, JCA, and JCB.