Common gate stage (CB7470E)

This circuit for FET was obtained from a 1977 Radio Handbook. The input impedance is 150 ohm. The output is high impedance.

Precision Tone Switch 4046 (CB25256E)
Using a 4046 PLL this circuit recognizes a 1.6 to 1.8 kHz tone by driving an output LED. The...
Battery charger with current and voltage limiter (CB9537E)
This battery charger circuit was found in ancient American documentation. The components are...
Solar Battery Test (CB1355E )
This circuit is of great use today, when solar energy is becoming increasingly important. The...