抄録
A small singal variance detection by an analogue technique and misdetection prevention algorithm to check transient variance integrity by digital technique is proposed. Real time acquisition of an one time signal variance is processed by two signal difference stages that make fluctuation as small as possible. Low S/N ratio signal difference is detected without averaging nor smoothing for S/N improvement. Misdetection prevention algorithm compensates analogue circuit's vulnerability to noise, rejecting similar variance more than two times during time window. Test signal generator was made to check one time small signal variance and multiple small signal variance, showing an effectiveness of noise rejection for proposed system. Fluctuation rejection experiments from 1Hz to 5kHz and multiple pulse testified that proposed detection system was effective to work under noisy environment. 0.5% relative signal variation for 5V gate input was detected with 9Vpp fluctuant noise from 1Hz to 100Hz. Total throughput after small signal variance event is lms.
