This circuit was found in a 1967 Electronics World. We can design it with a BF245 for the FET and a BC558 for the bipolar transistor. The circuit has 3 scales and a 10 M ohm input resistance.
We found this interesting timer circuit or CMOS timer in a 1988 publication. The circuit is still...
This circuit found in Radio Electronics can be used in games to produce a random pulse train. The...
We found this amplifier with high input impedance and low capacitance, using FET, in a...