QT designed instrumentation -modules-S3m-

S3m, isolated Voltage Source

This module is designed as a very low noise bias source for VI measurements.
It's output is fully isolated (floating source) , energy is send via an optical path.
The switch [V/V] sets the full scale (@1V control) voltage. The mute setting is there to check for offset/noise. The internal circuitry actually consists of an 100uA/V current source which is in parallel to a resistor to create a voltage source.

The voltage source has an output resistance (<1% error) that is 1kohm@range-100mV 100ohm@10mV 10ohm@1mV 1ohm@100uV.
The unit has 2 control inputs: x1 and x0.01, these can be used to have a dc-sweep (x1 input using a dac) with a modulation (lock-in on x0.01 via the iso-amp input).
The routing should be set in the summing module S2.
Example:When S3m placed in slot A, inputs are AV1 and AV2.
Sometimes the x0.01 input can be set jumpered to gnd in the module, for enabling modulation the wiring should be jumpered as on the picture: