Page 9
2.3
Construction
2.3.1 Electric function
The resistance elements are switched to the output terminals with reed relays in a binary code system.
The resistors are made of foil or metal with a low temperature coefficient. The relays used are types with
a low thermoelectric voltage.
The metal housing is connected to the ground terminal. Therefore the board with resistors and relays
creates independent mechanical block.
The CPU with a one-chip micro-controller generates all necessary internal control signals. Calibration
data and set-up parameters are saved in a EEPROM memory.
2.3.2 Mechanical construction
The decade housing is a standardized desktop housing made of aluminum. Keyboard and display are
located at the front panel.
The output terminals, the power cord socket with the fuse, the mains switch, the RS232 or the IEEE488
terminal and the ground terminal are located at the rear panel.
Summary of Contents for 1427
Page 4: ...Page 4...
