2-JFETs Oscillator (CB22396E)

This LC oscillator was found in English documentation from the 1990s. JFETs may be general-purpose equivalents.

555 Biofeedback Monitor (CB24775E)
This simple 555 biofeedback circuit was found in the December 1983 issue of Radio Electronics...
Water Tank Sensor with Alarm (CB16458E)
This circuit has a programmable alarm that can be triggered with different water levels. The...
Battery na alternator monitor (CB7136E)
Found in a 1991 Hobbyst Handbook, this circuit monitors both battery and alternator voltage. The set...