Circuit Diagram

Above is shown the general circuit diagram for each detector in SPARO. The bolometers and the Bias Resistors(20M) are located on the inner 3 He stage and are connected to the thermally isolated JFETs via rigid tensioned wires and stiff PC boards. The source resistor is located in the preamp in operation mode and in the test apparatus in load curve mode. The JFETS are powered with +/- 12 Volts via lead acid batteries.