Found in a 1967 Electronic Design, this circuit operates in a range of 0 to 1 V input with frequencies determined by C2. The components are from the period.
The circuit shown has a voltage gain of 500 times and can use equivalent FETs like the BF245. The...
Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using...
We found this circuit in an old publication from Argentina. The relay must be of the sensitive type,...