This module is designed as a floating bias/gate source providing up to +/-8V.
S1 has a floating output isolated with >10Gohm and 1pF from the other electronics and the supply. This output can only drive high impedance loads (20k or more) and the circuit for this is powered by a 9V-battery in the module.
Battery status can be checked on the source-control panel, switch (for a moment) the "x0.1/x1" switch to "x0.1" if the LED lights up then the 9V-battery is ok. (switch back because this check draws 10mA from that battery instead of the 4uA normal operation current)
Battery life is > 1 year.
Front-output: Vout=Vin(Iso-Amp) x gain
max. output =+/8V, (lemo pin 4/2)
source control panel: Gain: x1/x2 set by gain-knob position 1/2 (G1-G2)
battery check: switch (F1) to "x0.1"=check, LED (D1) "max" on=ok (momentary) (This is a check for the internal 9V-battery in module, not for the main batteries)
Replacing of the battery can be done by the user, remove the cover (max. 6 screws) and on the board a rectangular 9V alkaline can be replaced with double-sided sticky tape.
picture of battery on the board:
