This circuit allows you to read resistors up to 20 M ohms, converting it into voltage. The circuit is from the 90s. The operational ones used admit modern equivalents.
This high quality circuit with complementary symmetry was found in an Electronics World of 1966....
This circuit was obtained from an American documentation from the 1980s. The T1 triggering...
This circuit appeared in a noverber 1962s Practical Electronics. The magazine is no more, but the...