Group 1 - Qingdao Dingxin Communication Co., Ltd., Qingdao Zhidian New Energy Technology Co., Ltd., and Qingdao Dingxin Communication Power Engineering Co., Ltd. have obtained a patent for a signal processing circuit for Rogowski coils, which is applicable in the smart grid sector [1] - The patent features real-time measurement capabilities, fast response speed, and a wide current measurement range, ensuring measurement accuracy even under low current conditions [1] - The signal processing circuit includes components such as a passive RC integration circuit, low-pass filter circuit, T-type integration circuit, and anti-aliasing filter circuit, which work together to convert and process current signals [1] Group 2 - Qingdao Dingxin Communication Co., Ltd. was established in 2008 with a registered capital of 652.19 million RMB and has participated in 2,622 bidding projects [2] - Qingdao Zhidian New Energy Technology Co., Ltd. was founded in 2015 with a registered capital of 48.64 million RMB and has been involved in 142 bidding projects [2] - Qingdao Dingxin Communication Power Engineering Co., Ltd. was also established in 2015 with a registered capital of 7.5 million RMB and has participated in 27 bidding projects [2]