This high-precision circuit was found in a 1969 documentation. The components are from the period. R1 is 100 G ohms and C1 is 0.1 uF.
This circuit is from a 1979 publication. The sensor consists of plates or screens that, when...
Found in an 80's documentation this circuit uses an integrated from the uncommon era today. Other...
This circuit was found in a Popular Electronics from the 90s. It uses a LASCR which is a photo-SCR...