60 Hz Variations in Pins

1. 60 Hz Variations in Pins • Plugged probe into temperature controller output pins: pins 1, 2, 3, 4 all show 1Vp-p variations • Plugged probe into pins at other end of cable connected to temperature controller output: pins 1, 2, 3, 4 all show 200 mVp-p • Touched probe to wires connecting temperature controller cable and photodetector assembly: pins 1, 2, 3, 4 show 200 mVp-p variations if amp is not connected and 100 mVp-p variations if amp is connected

2. Other Characteristics • Temp controller on at 0.625 DC Amps, connected to photodetector, photodetector signal variations of 4 mVp-p • Temp controller on, but turned all the way down, takes ~10s to increase to 20 mVp-p • Temp controller switched off but connected to power and photodetector, 2 mVp-p • Temp controller disconnected from power, still connected to photodetector, 40 mVp-p, sensitive to my motion around electronics • Disconnect temp controller from photodetector from temp controller end of cable, 10 mVp-p, sensitive to motion • Disconnect temp controller from photodetector from photodetector end, variations are too small to distinguish from other variations/noise

3. Ground Schematic To Power Strip Labsphere photodetector casing Shielded Cable Cooler (+) Cooler (-) PS/TC-1 Controller Thermistor Thermistor InGaAs Photodetector and Temp Controller assembly BNC Cable Ground PD current signal Keithley Model 428 Current Amplifier Connected to Amp ground To Power Strip Connected to temp controller ground

4. Schematic for Analog Board Power Supply from Keithley Model 428 Current Amplifier Manual

5. Figure labeled “Typical Connections” from Keithley Model 428 Current Amplifier Manual Pictures of photodetector and temperature controller connections