This module is the general voltage amplifier.
It is a differential voltage amplifier presenting its output voltage at the iso-amp-out of the slot it is located in. The input stage of the amplifier is formed by the gates of FET-opamps, there are no terminating resistors added. Input impedance is very high (>10Gohm) also in "ac-coupling". As a consequence the input will slowly drift away when not connected, resulting in a overload signal at the corresponding iso-amp-out. This causes no damage to the circuit but the LED draws battery-current. To prevent this, when not in use, a short-circuit connector (Lemo pin 2-3-4) can be placed on the input when not in use (or switch to "ac").
All functions including "coupling ac/dc" can safely be operated during a measurement as switching is done after the input stage.
input:
front: V-in (lemo, pin 4=+in pin 3=ground pin 2=-in)
older models:(front:manual offset trim1 trim2)
output back:V-out (to iso-amp-out)
measure control panel:
Range: 1/10/100/1000/10.000 V/V switch: coupling ac/dc
Remote control for gain:1..10k V/V
Remote control for ac/dc mode
specs:
Input noise voltage: 10nV/sqrtHz Input noise current: 0.5fA/sqrtHz Input bias current : <1pA Bandwidth : 100kHz Drift : <0.5uV/c