The currents and voltages at which certain “switches” are made is programmed into the MAXX software and are subject to change.
The VZ and the VF routines may be interchanged and the orientation reversed to compensate. The VF routine is used if the current is more than 40MA and the voltage scale is 1.6V or 16V.
Voltage may be readout by the differential amplifier on the B501 or the single ended scales on the B552. The differential is used if the current is more than 400mA and the voltage scale is 1.6V or 16V.
The B534 board is used to generate reference currents at high levels and the B400 at low currents. The B534 is used above 4mA and it is disconnected below that level to avoid interaction between the boards.
ABOUT THE “B” MODEL
The “B” version of the FEC200 uses a B522 board in place of the B501 mentioned above. The B522 has several higher voltage differential scales that are used for Thyristor testing. It has a 32V scale that replaces the 16V scale mentioned above.