Models F10ADI and F20ADI are equipped with a phase inverter circuit that shares the input with the amplifier "1". It is intended to allow differential connection of the amplifiers to achieve double amplitude of the output signal. In such a case, the output of the phase inverter should be connected to the input of the second amplifier, an external signal supplied to the input of the first amplifier and the load connected between the outputs of both amplifiers as in the examplebelow:
Observe, that both sides of the connected load are active and must be isolated from ground. The voltage over the load is in this case U1 - U2 = U1 - (-U1) = 2U1 since U2 = -U1.
It is, of course, possible to supply separate signals to the low voltage inputs of both amplifiers and still use the differential connection of the load, as in the drawing.
The amplifiers can also be used as two independent units sharing the common groud reference.
Never connect any high voltage output to any input or output of the instrument!
In the differential configuration - isolate the load from ground and use 2 separate oscilloscope probes to monitor the voltage over the load.
Page updated February 22, 2006