RedShirtImaging, LLC.: Support: NeuroPlex Installation and Testing Procedures

Before plugging in the WuTech power supply, use an Ohm meter to measure the resistance between the power housing and ground to make sure the power housing is grounded. If the power supply is mounted on a rack, make sure the power supply housing has a very good contact to the rack and the rack has a very good ground line.

Without connecting to another part of the system, turn the power supply on. All of the LED indicators on the front panel should be on, indicating that the voltages are supplied. Measure the output voltages on the large output connector with a volt-meter. Make sure there are four supply voltages: +/- 15V and +/-7.2V to 8V. After the measurement turn off the power for a few seconds and turn it on and measure the output voltages again. Repeat this procedure three times. This will ensure that the output voltages did not change during shipment and the power supply is safe for the device.

If the line voltage is 220V, a special precaution is needed. In the factory the power supply was tested under 110V and then set to 220V input before shipping. Power under 220V was never tested. If the conversion was wrong, the power supply is likely to hold many minutes before it burns. During this time the output voltages would be correct. Thus it is extremely important to do the following test at a 220V area -- leave the power supply on for AT LEAST 10 MIN before connecting to the rest of the system. During this period if any abnormality occurs, such as a burned fuse, smoke or noise in the housing, unplug the plug on the wall and send the power supply back. If after ten minutes, there is no smoke and all the lights on the power supply are on, you can conduct the normal power-up test described above.

Turn off the power supply. Open the WuTech diode array by removing the side panel where the two cable bundles exit. Use a flashlight to inspect if any pre-amp cards are loose (they may appear higher than other cards).

Warning: NEVER touch the fiber-optics!!

Push the loose cards back in. If necessary, you can also remove the top plate of the array box. Close the side panel and tighten ALL the screws of that panel. This is important for achieving a light-tight and good shielding contact for the array housing.

Connect the array to the power supply by connecting the two small white three-lead connectors, one from the power supply and one from the array. Make sure that the gain is set on "low" for pre-amplifiers before turning on the power. Turn on the power supply while inspecting the LEDs on the Array housing. The two LEDs, +15V and -15V should be on, indicating the power to the array is correctly connected. Turn on the switch labeled "LED" on the array housing. Remove the cover on the fiber aperture by removing the four screws of the centering disk. Look into the array aperture. There should be five lit fibers at five corners of the hexagon. These lit fibers can be used for orienting the array and aligning the detectors to the image of the preparation. Warning: Do not touch the fiber optics aperture!! This aperture is softer than most of metals and is easily scratched. Turn off the LEDs and turn the gain switch to "low". Then turn off the Power supply for the next step.

Connect the two cable bundles from the array module to the post-amp cards. Place the PostAmp Module facing the array. Lay the cable bundles on top of the PostAmp Module down to the rear of the module. Looking into the rear of the module, you should see the input connectors of the second stage amplifier cards ( 2 connectors for each card, 16 in total). Plug the connectors top-down. When facing the rear of the PostAmp Module, the bundle labeled "left" should be plugged into the left row connectors.

Identify the power cable for the PostAmp Module. This is a short, multicolored and twisted wire cable with a 9-lead white block connector at the end. Connect this cable to the cable-of-the-same-type from the power supply module.

Identify the flat cable labeled # 4. On one end of this cable there are several connectors already connected to the PostAmp Module before shipping. On the other end is a 37 pin female "D" connector. Plug this connector to the 37 pin male "D" connector at the back of the Output-Amp Control Panel.

Replace the rear panel of the PostAmp Module. Use the four nylon spacers in between the rear panel and the rack to leave space for the cables. Make sure the computer is on and the two LED indicators for computer power on the front panel of the PostAmp Module are lit. Turn on the Power Supply Module while inspecting the LEDs on the front panel of the PostAmp Module. The four indicators, +/-15V, and +/- 8V should be all on indicating the power supply to the second stage is correctly connected.



		Warning: NEVER turn on the PostAmp power while the computer power is off. This is because the A/D converter can be damaged when the input voltage is higher than its power supply voltages. Always watch the indicators on the front panel of the PostAmp Module. If the computer power is off, turn off the Post Amp power immediately. This panel is designed with this purpose since some modern computers can be shut off with power saving or other software controls.

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Now when the PostAmp Module is on, LED indicators on the right half of the Output-Control panel are indicating the settings for the 2nd stage amplifiers. Use a black cloth to cover the array aperture and take data again. This data is the dark noise of the system. The RMS value of the dark noise can be obtained from the software. A measure for this system is follows: When the gain on the PreAmp is high(1Gohm) and Post Amp Gain=1000X, HP=AC2 and low pass filter = 500 Hz, the RMS noise for most of the detectors is around 300 mv. This value converts to an input current of the PreAmp of about 300 pA, close to the theoretical Johnson noise of the feedback resistor at 500 Hz bandwidth. If the dark noise is significantly higher than this value, make sure the array is sealed in the complete dark. Also, use the FFT function of the NeuroPlex to check if there is any 60 Hz noise in the system.