Periodic signal detector in high level noise - has AC component passed through amplifier and low-pass filter to be synchronously chopped to charge capacitors

摘要

The extraction and detection of a periodic signal which has associated high lebel noise where a synchronous signal is available. The detection equipment is comparatively cheap to produce, physically light, with a low volume and allows the signal in question to be reconstructed despite variations in its strength. The AC element of the composite input signal is extracted, amplified and filtered in a low-pass network. This component is then chopped synchronously, charging capacitors, the output being recovered by high input impedance separators as noise, signal, and DC components.