Whitening Filter Test and Abnormal Output
Today, we tested the whitening filter (D1302087) used in the magnetic field measurement system.
1. Increase in Noise with Analog Signal In Disconnected
The configuration card was inserted into the whitening filter, with all switches set to 0 (OFF).
The Analog Out was connected to the AA system, while the Analog Signal In (D-sub 15-pin) was left disconnected.
When the whitening filter was powered on, the RMS noise increased from approximately 0.0003 V to 0.0006 V.
This increase was observed on both Board 1 and Board 2.
2. Abnormal Output with the D-sub 15-pin Connected
On Board 2, the Analog Signal In (D-sub 15-pin) was connected to a conversion box that adapts the pin configuration for the magnetometer.
The magnetometer itself was not connected to the conversion box.
All switches on the configuration card were set to 0 (OFF).
When the whitening filter was powered on, an abnormal output reaching approximately 20 V was observed at Analog Out.
The waveform appeared to be oscillating, but the cause has not yet been identified. The Picture was attached.
To prevent possible damage to the circuit, we decided to stop further testing today after consulting with Yokozawa-san.
At present, the problem may be related to the internal wiring or grounding of the conversion box, but the cause remains unclear.
We plan to check the pin assignments and continuity of the wiring in the conversion box.
